RESUMEN
BACKGROUND: Cathepsin K is a cysteine protease with strong collagenolytic and elastolytic properties. Recently, cathepsin K expression in tumour cells of malignant melanoma and in the stromal cells of squamous cell carcinoma of the skin has been reported to play an important role in tumour progression. However, its expression profile in basal cell carcinoma (BCC) has not yet been clarified. OBJECTIVE: The aim of this study is to examine the expression profile of cathepsin K in both the tumour cells and the peritumoural stromal cells of BCC in comparison with its expression in normal skin. METHODS: Fifty consecutive operative cases of BCC, 10 cases of actinic keratosis, 10 cases of Bowen's disease and five normal skin tissues were assessed for cathepsin K expression by immunohistochemical methods. RESULTS: In normal skin, cathepsin K expression was observed in the stratum corneum, mature sebaceous cells and outer root sheath of the hair follicles. Cathepsin K was expressed in the tumour cells of all BCC cases, in which 90% showed diffuse expression (>51% of tumour cells), as well as in the peritumoural stromal cells in all BCC cases. Focal cathepsin K expression was observed in the tumour cells of Bowen's disease (2/10 cases), but not in any of actinic keratosis (0/10 cases). CONCLUSION: Cathepsin K expression may contribute to tumour invasion and peculiar histopathological features, such as fibromucinous stroma around the tumour nests by mediating extracellular matrix degradation in BCC.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Carcinoma Basocelular/enzimología , Catepsina K/metabolismo , Neoplasias Cutáneas/enzimología , Anciano , Anciano de 80 o más Años , Biopsia con Aguja , Enfermedad de Bowen/enzimología , Enfermedad de Bowen/patología , Enfermedad de Bowen/cirugía , Carcinoma Basocelular/patología , Carcinoma Basocelular/cirugía , Estudios de Casos y Controles , Progresión de la Enfermedad , Femenino , Humanos , Inmunohistoquímica , Queratosis Actínica/enzimología , Queratosis Actínica/patología , Queratosis Actínica/cirugía , Masculino , Persona de Mediana Edad , Invasividad Neoplásica/patología , Pronóstico , Valores de Referencia , Medición de Riesgo , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugíaRESUMEN
No conservative treatments for chylothorax have yet been established, and surgical ligation of the thoracic duct is required in many cases. In the present study, we investigated the management of body fluid in a canine chylothorax model. Twelve beagle dogs were divided evenly into three groups: A, B, and C. Under general anesthesia, the thoracic duct was cut and opened, and the amount of lymph fluid leakage was measured. Intravenous extracellular fluid infusion was started at 5mL/kg/h for the first 2h, and then between 2 and 4h, the infusion rate was increased to 10 mL/kg/h in group A and to 20mL/kg/h in group B. During the first 2h after cutting the thoracic duct, the mean lymph fluid leakage rates in groups A, B, and C were 0.466, 0.635, and 0.575 mL/kg/h, respectively. The rates of leakage did not differ significantly among the groups. Between 2 and 4h, the mean rates of leakage were 0.750, 1.43, and 0.544mL/kg/h, respectively, being significantly higher in groups A and B than in group C. The amount of lymph fluid ascending the thoracic duct correlates with the amount of intravenous fluid infusion. For the management of chylothorax, it is important to avoid fluid overload.
Asunto(s)
Quilo/metabolismo , Quilotórax , Fluidoterapia/efectos adversos , Animales , Quilotórax/etiología , Perros , Verde de Indocianina/administración & dosificación , Infusiones Intravenosas , Modelos Animales , Conducto Torácico/metabolismoRESUMEN
We undertook this study to determine the role of Microsomal PGE Synthase-1 (mPGES-1), and mPGES-1-generated Prostaglandin (PG) E2 on Dendritic Cell (DC) phenotype and function. Using mPGES-1 KnockOut (KO) mice, we generated bone marrow derived DCs and determined their eicosanoid production profile, cell surface marker expression, and cytokine production. We also assessed DC migratory and functional capacity in vivo. Compared to wild-type, mPGES-1 deficient DCs exhibited a markedly attenuated increase in PGE2 production upon LPS stimulation, and displayed preferential shunting towards PGD2 production. mPGES-1 KO DCs did not display deficiencies in maturation, migration or ability to sensitize T cells. However, mPGES-1 deficient DCs generated reduced amounts of the Th1 cytokine IL-12, which may in part be due to increased PGD2 rather than decreased PGE2. These findings provide useful information on the effects of inducible PGE2 on the innate immune system, and have important implications regarding potential consequences of pharmacologic mPGES-1 inhibition.
Asunto(s)
Citocinas/metabolismo , Células Dendríticas/metabolismo , Dinoprostona/biosíntesis , Oxidorreductasas Intramoleculares/genética , Animales , Movimiento Celular/genética , Cricetinae , Eliminación de Gen , Interleucina-12/metabolismo , Oxidorreductasas Intramoleculares/metabolismo , Lipopolisacáridos/farmacología , Ratones , Ratones Noqueados , Prostaglandina-E Sintasas , RatasRESUMEN
The roles of prostanoids in the pathogenesis of cardiovascular diseases and in the development of pathological conditions have been examined using mice lacking the individual, specific prostanoid receptor. Prostaglandin (PG) I2 protected the heart from ischemia-reperfusion injury in a model of acute myocardial infarction. In addition, PGI2 suppressed the development of pressure overload-induced cardiac hypertrophy. Aside from its potent vasodilatory action, PGI2 contributed critically to the development of renovascular hypertension via the activation of the renin-angiotensin-aldosterone system. Thromboxane (TX) A2 and PGF2alpha were found to be the mediators of inflammatory tachycardia under a systemic inflammatory condition induced by lipopolysaccharide. Under a septic condition leading to a vascular hypo-responsive state, TXA2 worked to maintain vascular tone by inhibiting the induction of inducible nitric oxide synthase in vascular smooth muscle cells. Mice lacking the PGE2 receptor subtype EP3 had a bleeding tendency and were resistant to thromboembolism, due to a defective activation of platelets. From these studies, the important and novel roles of prostanoids in the pathogenesis of cardiovascular diseases have been clarified.
Asunto(s)
Enfermedades Cardiovasculares/metabolismo , Prostaglandinas/metabolismo , Transducción de Señal , Animales , Plaquetas/metabolismo , Cardiomegalia/metabolismo , Cardiomegalia/prevención & control , Enfermedades Cardiovasculares/genética , Enfermedades Cardiovasculares/fisiopatología , Enfermedades Cardiovasculares/prevención & control , Dinoprost/metabolismo , Epoprostenol/metabolismo , Hemodinámica , Humanos , Hipertensión Renovascular/metabolismo , Mediadores de Inflamación/metabolismo , Ratones , Ratones Noqueados , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/prevención & control , Receptores de Prostaglandina/deficiencia , Receptores de Prostaglandina/genética , Receptores de Prostaglandina/metabolismo , Sepsis/metabolismo , Transducción de Señal/genética , Taquicardia/metabolismo , Tromboxano A2/metabolismoRESUMEN
The objective of this experiment was to determine the effect of prepartum lipid supplementation on the number and quality of embryos recovered following ovarian super-ovulation in postpartum suckled beef cows. Mature cows (n = 40) were assigned to one of two treatments (lipid versus. no lipid) and supplemented for approximately 40 days prior to calving. Supplements provided to cows were isocaloric and isonitrogenous. The treatment group was fed 1.6 kg hd(-1) per day of whole soybeans (WSB; 19.8% ether extract, and 41.8% crude protein) and the control group received a supplement consisting of 1.8 kg hd(-1) day of a soybean meal and soy-hull combination (SBS; 2.15% EE and 36.81% CP). Cows were synchronized using a GnRH [Cystorelin((R)) 100 microg im]-GnRH-PGF(2alpha) [Lutalyse 25 mg im] protocol. Cows were administered two injections of GnRH seven days apart and PG seven days after the second GnRH injection. Twenty-eight cows (WSB, n = 15; SBS, n = 13) responded to estrus synchronization and were superstimulated. Super-ovulation was initiated on day 8-10 of the synchronized cycle by twice-daily injections of pFSH (Pluset) over four days in decreasing doses using a total of 608.4 IU per cow. Prostaglandin F(2alpha) was administered 96 and 108 h after super-stimulation was initiated with FSH. Days postpartum (WSB = 59 days; SBS = 57 days) at initiation of FSH treatments were similar (P > 0.10) for both treatments. Cows were monitored for estrus activity by the HeatWatch Estrus Detection System. Twenty-seven cows (WSB, n = 15; SBS, n = 12) exhibited estrus after FSH and inseminated at 0, 12, and 24 h after the onset of estrus with 1, 2, and 1 units of semen, respectively. Embryos were recovered and evaluated 7-8 days later. Only cows that responded to FSH and that were inseminated were used for statistical analysis. Data were analyzed using the General Linear Models Procedure of SAS. Body condition scores did not differ (P > 0.10) between treatments when cows were evaluated at the initiation of the experiment, two weeks prior to calving, and at initiation of superovulation with FSH. Estrous cyclicity prior to the initiation of estrus synchronization did not differ (P > 0.10) between treatments. There was no difference (P > 0.10) between treatments in recovery of total embryos (WSB, 14.7 +/- 3.5; SBS, 17.5 +/- 3.0), transferable embryos (WSB, 10.3 +/- 2.5; SBS, 13.6 +/- 2.6), degenerate embryos (WSB, 3.3 +/- 1.1; SBS, 1.6 +/- 1.7) or unfertilized ova (WSB, 1.1 +/- 0.5; SBS, 2.3 +/- 1.2). Cows that were supplemented with whole soybeans prior to parturition failed to produce an increased total number of ova or transferable embryos following super-ovulation.
Asunto(s)
Bovinos/fisiología , Transferencia de Embrión/veterinaria , Hormona Folículo Estimulante/administración & dosificación , Lípidos/administración & dosificación , Paridad , Superovulación , Animales , Dieta , Proteínas en la Dieta/administración & dosificación , Dinoprost/administración & dosificación , Sincronización del Estro , Femenino , Hormona Liberadora de Gonadotropina/administración & dosificación , Embarazo , Glycine maxRESUMEN
The experimental objective was to compare pregnancy rates after fixed-time AI in postpartum suckled beef cows following administration of two progestin-based protocols to synchronize ovulation. Cows (n = 424) at three locations (n = 208, 122, and 92 per location) were stratified by age, BCS, and days postpartum (DPP) and assigned randomly to one of the two treatment protocols. The MGA Select-treated cows (MGA Select; n = 213) were fed melengestrol acetate (MGA, 0.5 mg x cow(-1) x d(-1)) for 14 d and carrier for 8 d, and then GnRH (100 microg i.m. Cystorelin; d 26) was injected 12 d after MGA withdrawal, and PG (25 mg i.m. Lutalyse) was administered 7 d after GnRH. Cows assigned to the 7-11 Synch protocol (7-11 Synch; n = 209) were fed carrier for 15 d and MGA for 7 d, and then injected with PG on d 22 (d 7 of MGA), GnRH on d 26, and PG again on d 33. Artificial insemination was performed at fixed times for cows in both treatments at 60 or 72 h after d 33 PG for 7-11 Synch and MGA Select groups, respectively. All cows were injected with GnRH (100 microg of i.m. Cystorelin) at AI. There was no treatment x location interaction for age (P = 0.90), BCS (P = 0.64), or DPP (P = 0.93), and the results were therefore pooled for the respective treatments (age [7-11 Synch, 5.5 +/- 0.2; MGA Select, 5.5 +/- 0.2], BCS [7-11 Synch, 5.7 +/- 0.1; MGA Select, 5.6 +/- 0.1], and DPP [7-11 Synch, 41.1 +/- 1.1; MGA Select, 42.1 +/- 1.1]). Blood samples were collected 8 and 1 d before MGA or carrier to determine pretreatment estrous cyclicity (progesterone >or=1 ng/mL; 7-11 Synch, 59/209 [28%]; MGA Select, 54/213 [25%]; P = 0.50) and again on d 33 PG to evaluate treatment response as a percentage of cows with progesterone concentrations in serum >or=1ng/mL (7-11 Synch, 184/209 [88%]; MGA Select, 177/213 [83%]; P = 0.15). Pregnancy rates resulting from fixed-time AI did not differ (P = 0.25) between treatments (7-11 Synch, 128/209 [61%]; MGA Select, 142/213 [67%]), nor did pregnancy rates (P = 0.77) at the end of the breeding season (7-11 Synch, 198/208 [95%]; MGA Select, 204/213 [96%]). These data indicate that pregnancy rates were comparable after fixed-time AI, following administration of the 7-11 Synch and MGA Select protocols. Both protocols provide opportunities for beef producers to use AI and eliminate the need to detect estrus.
Asunto(s)
Bovinos/fisiología , Sincronización del Estro/métodos , Glucocorticoides/farmacología , Inseminación Artificial/veterinaria , Acetato de Melengestrol/farmacología , Animales , Dinoprost/administración & dosificación , Dinoprost/análogos & derivados , Dinoprost/farmacología , Sincronización del Estro/efectos de los fármacos , Femenino , Glucocorticoides/administración & dosificación , Hormona Liberadora de Gonadotropina/administración & dosificación , Hormona Liberadora de Gonadotropina/farmacología , Inseminación Artificial/métodos , Lactancia , Modelos Logísticos , Acetato de Melengestrol/administración & dosificación , Embarazo , Índice de Embarazo , Progesterona/sangre , Prostaglandinas/administración & dosificación , Distribución Aleatoria , Factores de TiempoRESUMEN
Two progestin-based protocols for estrus synchronization in replacement beef heifers were compared on the basis of estrous response, interval to and synchrony of estrus, and pregnancy rate. The objective was to determine, whether addition of GnRH to a melengestrol acetate (MGA)-prostaglandin F2alpha (PGF2alpha) estrus synchronization protocol would improve synchrony of estrus without compromising fertility in yearling beef heifers. Heifers at two locations (Location 1, n = 60 and Location 2, n = 64) were assigned randomly to one of two treatments by breed and pubertal status. Heifers were defined as, pubertal when concentrations of progesterone in serum were elevated (> or = 1 ng/mL) in either one of two samples obtained 10 and 1 day prior to treatment initiation. Prior to MGA administration, 18/60 (30%) and 36/64 (56%) of the heifers at Locations 1 and 2, respectively, were pubertal. Heifers in both treatments were fed MGA (0.5 mg/head/day in 1.8 kg/head/day supplement) for 14 days followed by 25 mg of PGF2alpha i.m. (MGA-PGF2alpha) 19 days after MGA withdrawal (Day 33 of treatment). One-half of the heifers at each location received 100 microg of GnRH i.m. 12 days after MGA withdrawal (Day 26 of treatment; MGA Select). The control group received only MGA-PGF2alpha. Heifers were observed for signs of behavioral estrus continuously during daylight hours for 7 days beginning on the day PGF2alpha was administered. Heifers were inseminated 12 h after observed estrus. There was a treatment by location by pubertal status interaction (P < 0.05) for interval to estrus. Compared to the respective control treatment at each location, prepubertal heifers assigned to the MGA Select protocol at Location 1 had longer intervals to estrus, whereas at Location 2, prepubertal heifers assigned to the MGA-PGF2alpha protocol had longer intervals to estrus. The higher number of pubertal heifers at Location 2 was associated with a reduced variance in the interval to estrus among MGA Select treated heifers. Total estrous response and synchronized conception rates were similar between treatments at both locations. These data suggest that addition of GnRH to the MGA-PGF2alpha protocol may improve synchrony of estrus, however, the degree of synchrony may be influenced by pubertal status of heifers at the time treatments are imposed. Further studies are needed to define production systems in which the MGA Select protocol is warranted for use in beef heifers.
Asunto(s)
Bovinos/fisiología , Sincronización del Estro/métodos , Progestinas/administración & dosificación , Maduración Sexual , Animales , Dieta , Dinoprost/administración & dosificación , Estro/fisiología , Femenino , Hormona Liberadora de Gonadotropina/administración & dosificación , Embarazo , Índice de Embarazo , Progesterona/sangre , Factores de TiempoRESUMEN
The hypothesis was the greater the magnitude of acute increase in circulating concentration of progesterone of female cattle, the greater the acute inhibitory effect on frequency of pulsatile LH release. From Day 0 to 4 of the treatment period, females without functional corpora lutea were treated with varying doses of progesterone to result in varying concentrations of progesterone within the typical physiological range in blood. From Day 4 to 7, cattle were treated with a single dose of progesterone to achieve a similar circulating concentration of progesterone among all females in the study. Therefore, from Day 0 to 4 relative to Day 4 to 7 of the treatment period, females had a: (1) large (3.1 ng/ml), (2) moderate (2.5 ng/ml), or (3) small (0.5 ng/ml) increase in concentration of progesterone in blood. Frequency of LH pulses was greater (P <0.10) in females with the greatest magnitude of change in concentration of progesterone during the first 24 h following the change in concentration as compared with females with the moderate or small of change in concentration of progesterone suggesting our working hypothesis should be rejected. The greater the magnitude of acute change in concentration of progesterone, however, the longer time required for re-initiation of release of LH pulses of the amplitude of pulses that preceded the change in concentration of progesterone.
Asunto(s)
Bovinos/fisiología , Ciclo Estral/fisiología , Hormona Luteinizante/fisiología , Progesterona/fisiología , Animales , Bovinos/sangre , Estradiol/sangre , Estradiol/fisiología , Sincronización del Estro , Femenino , Análisis de los Mínimos Cuadrados , Hormona Luteinizante/sangre , Hormona Luteinizante/metabolismo , Progesterona/sangre , Radioinmunoensayo/veterinaria , Distribución AleatoriaRESUMEN
Two progestin-based protocols for estrus synchronization in postpartum beef cows were compared following treatment administration on the basis of estrous response, interval to and synchrony of estrus, and pregnancy. Cows were assigned to one of the two treatment protocols by age, body condition score (BCS), and days postpartum (DPP). The MGA Select-treated cows (MGA Select; n = 109) were fed melengestrol acetate (MGA; 0.5mg x cow-1 x d(-1)) for 14 d, fed carrier for 8 d, GnRH (100 microg of Cystorelin) was injected i.m. 12 d after MGA withdrawal, and PG (25 mg of Lutalyse) was administered i.m. 7 d after GnRH. Cows assigned to the 7-11 Synch protocol (7-11 Synch; n = 111) were fed carrier for 15 d, fed MGA for 7 d, injected with PG on d 22 (d 7 of MGA), injected with GnRH on d 26, and injected with PG on d 33. Mean BCS (4.8 +/- 0.1, MGA Select; 4.7 +/- 0.1, 7-11 Synch) and DPP (40 +/- 1, MGA Select; 40 +/- 1, 7-11 Synch) did not differ between treatments. Blood samples were collected 8 d and 1 d before feeding of MGA or carrier to determine the pretreatment estrous cyclicity (progesterone > or = 1 ng/mL; 10/109 [9%], MGA Select; 12/111 [11%], 7-11 Synch), and again at PG on d 33 to evaluate treatment response (81/109 [74%], MGA Select; 84/111 (76%), 7-11 Synch). Serum concentrations of progesterone at PG on d 33 differed (P < 0.01) between treatments (3.3 +/- 0.3 ng/mL [MGA Select] vs. 1.7 +/- 0.1 ng/mL [7-11 Synch]). HeatWatch was used for 6 d after PG on d 33 to detect estrus, and AI was performed 12 h after the onset of estrus. Estrous response did not differ between treatments (100/109 [92%], MGA Select; 101/111 [91%], 7-11 Synch). Mean interval to estrus (65 +/- 2.7 h, MGA Select; 52 +/- 1.8 h, 7-11 Synch) and synchrony of estrus differed (P < 0.01) between treatments. Synchronized conception and pregnancy rates (61/100 [61%], 61/109 [56%], MGA Select; 71/101 [70%], 71/111 [64%], 7-11 Synch), and final pregnancy rates (94/109 [86%], MGA Select; 99/110 [90%], 7-11 Synch) did not differ between treatments. In summary, estrous response and fertility did not differ among cows assigned to the MGA Select or 7-11 Synch protocols. Synchrony of estrus, defined as the variance in the interval to estrus from PG, however, was improved following treatment with the 7-11 Synch protocol.
Asunto(s)
Bovinos/fisiología , Dinoprost/análogos & derivados , Dinoprost/farmacología , Sincronización del Estro/efectos de los fármacos , Fármacos para la Fertilidad Femenina/farmacología , Hormona Liberadora de Gonadotropina/farmacología , Acetato de Melengestrol/farmacología , Congéneres de la Progesterona/farmacología , Animales , Constitución Corporal/fisiología , Dinoprost/administración & dosificación , Sincronización del Estro/métodos , Femenino , Fármacos para la Fertilidad Femenina/administración & dosificación , Glucocorticoides/farmacología , Hormona Liberadora de Gonadotropina/administración & dosificación , Inseminación Artificial/veterinaria , Acetato de Melengestrol/administración & dosificación , Periodo Posparto/efectos de los fármacos , Periodo Posparto/fisiología , Embarazo , Índice de Embarazo , Progesterona/sangre , Congéneres de la Progesterona/administración & dosificación , Distribución Aleatoria , Factores de TiempoRESUMEN
Two progestin-based protocols for the synchronization of estrus in beef cows were compared. Cyclic, nonlactating, crossbred, beef cows were assigned by age and body condition score to one of two treatments. Cows assigned to the MGA Select protocol were fed melengestrol acetate (MGA; 0.5 mg x cow(-1) x (-1)) for 14 d, GnRH was administered (100 microg i.m. of Cystorelin) 12 d after MGA withdrawal, and PGF2alpha (25 mg of i.m. Lutalyse) was administered 7 d after GnRH. Cows assigned to the 7-11 Synch protocol were fed MGA for 7 d and were injected with PG on d 7 of MGA, GnRH on d 11, and PG on d 18. Transrectal ultrasonography was performed daily to monitor follicular dynamics from the beginning of MGA feeding through ovulation after the synchronized estrus. All cows exhibited estrus in response to PG. Mean interval to estrus was shorter (P < 0.01) for 7-11 Synch-treated cows (56 +/- 1.5 h) than for cows assigned to the MGA Select protocol (73 +/- 4.7 h). Mean interval from estrus to ovulation did not differ between treatments (P > 0.10). Variances for interval to estrus differed (P < 0.01) between treatments. Mean follicular diameter at GnRH injection, PG injection, and estrus did not differ (P > 0.10) between treatments. Relative to MGA Select, serum estradiol-17beta concentrations were higher (P < 0.01) for 7-11 Synch 2 d and 1 d before, on the day of GnRH injection, in addition to 4 d after GnRH, and 24 h after PG. Mean progesterone concentrations were greater (P < 0.01) for MGA Select cows from 4 d before to 7 d after GnRH. Forty-four percent of the variation in interval to estrus between treatments was explained by differences in estradiol-17beta concentrations 24 h after PG. This study suggests that follicular competence is likely related to steroidogenic capacity of the follicle and the endocrine environment under which growth and subsequent ovulation of the dominant follicle occurs.
Asunto(s)
Bovinos/fisiología , Dinoprost/farmacología , Sincronización del Estro/efectos de los fármacos , Fármacos para la Fertilidad Femenina/farmacología , Hormona Liberadora de Gonadotropina/farmacología , Acetato de Melengestrol/farmacología , Congéneres de la Progesterona/farmacología , Factores de Edad , Animales , Constitución Corporal/fisiología , Bovinos/sangre , Dinoprost/administración & dosificación , Sincronización del Estro/métodos , Femenino , Glucocorticoides/farmacología , Acetato de Melengestrol/administración & dosificación , Folículo Ovárico/diagnóstico por imagen , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , Ovulación , Embarazo , Progesterona/sangre , Congéneres de la Progesterona/administración & dosificación , Distribución Aleatoria , Factores de Tiempo , Resultado del Tratamiento , UltrasonografíaRESUMEN
The objective was to determine the appropriate timing of fixed-time artificial insemination (AI) following administration of the MGA Select protocol. Cows at two locations (Location 1, n=114; Location 2, n=97 ) were assigned to fixed-time AI at 72 or 80 h by age, body condition score (BCS), days postpartum (DPP), AI technician, and sire. All cows were synchronized with the MGA Select protocol, consisting of oral administration of melengestrol acetate (MGA; 0.5mg/hd per day) for 14 days, GnRH (Cysotrelin, 100 microg, i.m.; Day 26) 12 days after MGA withdrawal, followed in 7 days with PGF(2alpha) (PG; Lutalyse, 25mg i.m.; Day 33). Cows were inseminated at 72 h ( n=108 ) or 80 h ( n=103 ) after PG and GnRH (100 microg) was given at insemination. Location was not significant and, therefore, was removed from the model. Mean BCS ( 5.2+/-0.1, 72 h; 5.3+/-0.1, 80 h) and DPP ( 34+/-2, 72 h; 35+/-2, 80 h) did not differ ( P>0.1 ) between treatments. Serum progesterone concentrations 7 and 1 day prior to MGA were used to determine pre-treatment cyclicity: cows with at least one sample with progesterone > or =1 ng/ml were defined as cyclic (33/108, 31%, 72 h, versus 32/103, 31%, 80 h; P>0.1). Cows with serum progesterone concentrations > or =1 ng/ml on the day of PG were defined as responding to the synchronization protocol (74/108 (69%), 72 h versus 69/103 (67%), 80 h; P>0.1 ). Although pregnancy rates were higher ( P<0.05 ) for cows inseminated at 72 h (69/108, 64%) versus 80 h (52/103, 50%) after PG, pregnancy rates at the end of the breeding season did not differ ( P>0.1 ) between treatments (98/108 (91%), 72 h; 88/103 (85%), 80 h). In conclusion, pregnancy rates were higher when postpartum beef cows synchronized with the MGA Select protocol were inseminated at 72 h versus 80 h after PG.
Asunto(s)
Bovinos/fisiología , Dinoprost/administración & dosificación , Hormona Liberadora de Gonadotropina/administración & dosificación , Inseminación Artificial/veterinaria , Acetato de Melengestrol/administración & dosificación , Animales , Cruzamiento , Sincronización del Estro/métodos , Femenino , Inseminación Artificial/métodos , Periodo Posparto , Embarazo , Progesterona/sangre , Factores de TiempoRESUMEN
The objectives of the present study were to determine how varying frequency of LH pulses as controlled by varying treatments with progesterone (P4) in cattle would affect: (1) concentration of steroid hormones and activity of insulin-like growth factor binding proteins (IGFBPs) in the ovarian follicular fluid and blood plasma, and (2) duration of persistence of largest ovarian follicles. There were four treatment groups (n=7 per group) and a control group (n=5) of mature, non-lactating beef cows. Treatments were: (1) two progesterone releasing intravaginal devices (PRIDs) for 16 days (2PRID); (2) a half PRID for 16 days (0.5PRID); (3) two PRIDs for 8 days, then a half PRID for 8 days (2-0.5PRID); or (4) a half PRID for 8 days, then two PRIDs for 8 days (0.5-2PRID). Treatment was initiated on the fifth day of the estrous cycle, which was designated as Day 0, and continued for 16 days. All P4-treated females were administered prostaglandin F2alpha on Day 0 and 1 to regress their corpora lutea. Frequency of LH pulses was greater during treatment with the smaller dose of P4 compared with treatment with the larger dose of P4 and the control group. Ovarian follicles were classified into five categories based on ultrasonographic observations: growing (G); atretic (A); growing dominant (GD); growing persistent (GP); or atretic persistent (AP). At ovariectomy on Day 16, the largest and second largest follicles collected were re-classified into five categories based on follicular concentration of steroids. Classification of the largest follicle collected on Day 16 was influenced by treatment (P<0.005), with the 2PRID group having A follicles, the 2-0.5PRID group GP follicles, the 0.5-2PRID group AP follicles, and the 0.5PRID group GD and GP follicles. Concentrations of 17beta-estradiol (E2) were greatest in GD and GP follicles (P<0.05). There was less (P<0.05) activity of IGFBP-2 in GD follicles and less (P<0.05) activity of IGFBP-3 in GD and GP follicles than other follicles. Activity of IGFBP-4 and -5 was greater (P<0.05) in A and AP follicles than G, GD, and GP follicles. Maintenance of a frequent release of LH pulses over a 16-day period did not result in maintenance of persistent follicles throughout this period indicating that duration of dominance of these follicles is finite even when there is frequent release of LH pulses. Follicular atresia is associated with greater activity of IGFBP-2, -4, -5, and greater concentrations of P4 in follicles, whereas growing dominant and persistent follicles contained greater concentrations of E2, androstenedione (A4), and less IGFBP-2 activity than follicles of other classes. Follicle classifications based on ultrasonography or follicular concentration of steroids did differ (P<0.05) for the largest follicles from the 2PRID group. Two follicles in this group appeared as GD follicles by ultrasonography, but these were atretic based on follicular steroid contents. Objective 1 of the present study yielded the conclusion that concentrations of steroid hormones in follicular fluid and blood plasma could be predictably controlled by regulating the frequency of LH pulses with varying doses of P4. Objective 2 yielded the conclusion that maintain frequent release of LH pulses over a 16-day period could not maintain persistent follicles throughout this period, indicating that duration of dominance of these follicles is finite even when there is frequent release of LH pulses. Follicular atresia in the present study was associated with increased follicular fluid activity of IGFBP-2, -4, -5, and P4, whereas growing dominant and persistent follicles contained greater concentrations of E2, A4, and less IGFBP-2 activity than follicles of other classes.
Asunto(s)
Líquido Folicular/química , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina/análisis , Hormona Luteinizante/metabolismo , Folículo Ovárico/fisiología , Progesterona/administración & dosificación , Esteroides/análisis , Administración Intravaginal , Animales , Estradiol/análisis , Estradiol/sangre , Femenino , Hormona Folículo Estimulante/sangre , Atresia Folicular , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/análisis , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/análisis , Proteína 4 de Unión a Factor de Crecimiento Similar a la Insulina/análisis , Proteína 5 de Unión a Factor de Crecimiento Similar a la Insulina/análisis , Hormona Luteinizante/sangre , Folículo Ovárico/diagnóstico por imagen , Periodicidad , Progesterona/análisis , Progesterona/sangre , UltrasonografíaRESUMEN
An oestrous synchronisation protocol was developed for use in lactating dairy cows using PGF(2alpha), GnRH, and oestradiol cypionate (ECP). In experiment 1, lactating dairy cows received two injections of PGF(2alpha) (on days 0 and 11) (PP; n=10) or two injections of PGF(2alpha) (days 0 and 11) and 100 microg of GnRH on day 3 (PGP; n=10). In experiment 2, cows were treated with PGP (n=7), or PGP and 1 mg of ECP at the same time (PGPE(0); n=7) or 1 day after the second PGF(2alpha) injection (PGPE(1); n=7). In experiment 3, 101 lactating dairy cows in a commercial herd were assigned to one of three treatments; PP, PGP, or PGPE(1). Follicular growth was measured by ultrasound in experiments 1 and 2. Every cow (experiments 1, 2, and 3) was blood sampled at selected intervals for progesterone and oestradiol assays and inseminated at oestrus. In experiment 1, a higher percentage of GnRH-treated cows ovulated after the first PGF(2alpha) injection (90% versus 50%; P<0.05). The GnRH-treated cows tended to have a larger dominant follicle present at the time of the second PGF(2alpha) injection (16.5+/-0.5 mm versus 15.0+/-0.7 mm; P<0.10). The percentage of cows that ovulated after the second PGF(2alpha) injection was similar (60%). In experiment 2, cows treated with ECP had higher peak preovulatory concentrations of oestradiol in plasma (6.99+/-0.63 versus 3.63+/-0.63; P<0.01) following the second PGF(2alpha) injection and a higher percentage ovulated (86% versus 43%; P<0.05). A higher percentage of PGPE(1)-treated cows in experiment 3 were observed in standing oestrus and ovulated after the second PGF(2alpha) injection (standing oestrus, 26.4, 34.3, and 62.6%, P<0.01; ovulated, 56, 63, and 78%, P<0.05; PP, PGP, and PGPE(1), respectively). In conclusion, the PGP protocol increased the number of cows that ovulated after the first PGF(2alpha) injection and produced a more mature dominant follicle at the time of the second PGF(2alpha) injection. Adding ECP to PGP (PGPE(1)) enhanced the expression of oestrus and increased ovulation percentage. The combination of PGP and ECP is potentially a new method to routinely synchronise oestrus and ovulation in dairy cows.
Asunto(s)
Bovinos/fisiología , Dinoprost/administración & dosificación , Estradiol/análogos & derivados , Estradiol/administración & dosificación , Sincronización del Estro/métodos , Hormona Liberadora de Gonadotropina/administración & dosificación , Animales , Estradiol/sangre , Femenino , Folículo Ovárico/anatomía & histología , Ovulación , Progesterona/sangre , Factores de TiempoRESUMEN
Although treatment of cycling cows with low concentrations of melengesterol acetate (MGA) results in formation of persistent follicles, in the absence of corpora lutea, it is not known whether persistent follicles form in anestrous cows in response to a similar treatment. The objective of this experiment was to determine the effect of long-term MGA treatment (14 d) on follicular dynamics and the secretion of estradiol in anestrous postpartum beef cows. Treatment groups (replicated over 2 yr) included the following: anestrous control (AC; n = 11), anestrous MGA (AM; n = 16), and cycling MGA (CM; positive control; n = 16). Angus-crossbred cows were assigned to treatment by age, cow body condition, and days postpartum. Cows were fed carrier (AC group) or 0.5 mg MGA x animal(-1) x d(-1) (AM and CM groups) for 14 d beginning approximately 38 d postpartum. Cows allotted to the CM group were injected with PGF2alpha, on the first day of MGA treatment to induce luteolysis. The preceding treatment (CM) results in formation of persistent follicles and secretion of elevated concentrations of estradiol. Ovaries of each cow were examined daily by transrectal ultrasonography beginning 5 to 7 d preceding the initiation of feeding MGA or carrier and continued until ovulation or 7 d following MGA feeding. There was no difference among groups in the stage of follicular wave or diameter of the largest follicle at the start of carrier or MGA feeding. The length of the follicular wave present at the start of MGA feeding was greater (P < 0.01) for cows in the CM (14.5 d, yr 1; 18.3 d, yr 2) group compared to the AM (9.4 d, yr 1; 7.9 d, yr 2) or AC (9.7 d, yr 1; 10.7 d, yr 2) groups. Maximum follicular diameter over both years was greater (P < 0.01) for the CM (20.6 mm) group than the AM (15.1 mm) or AC (16.4 mm) groups. Circulating concentrations of estradiol were also increased (P < 0.05) in the CM group compared to the AM or AC groups. However, MGA appeared to have no effect (P > 0.05) on the number of follicles recruited, growth rate of the dominant follicle during the first 6 d oftreatment, or growth rate to the maximum follicular diameter. In summary, MGA treatment did not increase the duration ot the follicular wave, maximum follicular diameter, or secretion of estradiol in anestrous postpartum cows, nor did MGA affect the number of follicles recruited or growth rate of dominant follicles in cycling or anestrous animals.
Asunto(s)
Bovinos/fisiología , Estradiol/metabolismo , Acetato de Melengestrol/farmacología , Folículo Ovárico/efectos de los fármacos , Congéneres de la Progesterona/farmacología , Administración Oral , Anestro , Animales , Cuerpo Lúteo/efectos de los fármacos , Dinoprost/administración & dosificación , Femenino , Ovulación , Inducción de la Ovulación/métodos , Inducción de la Ovulación/veterinaria , Periodo PospartoRESUMEN
The hypothesis that ovulation in response to short-term (48 h) calf removal (CR) is dependent on the developmental stage of the dominant follicle was tested in two studies. The objective of Exp. 1 was to characterize the fate of a dominant follicle following 48-h CR on d 2, 4, or 8 of a postpartum follicular wave. Ovaries of 61 beef cows were examined daily by transrectal ultrasonography starting at d 20 to 21 postpartum. Treatments were no CR (n = 14) and CR on d 2 (n = 12), 4 (n = 16), or 8 (n = 10) of first detected follicular wave. Percentage of cows that ovulated a dominant follicle following treatment was not different among groups (P = 0.62). Maximum size of dominant follicles was larger in cows that ovulated (P = 0.002) than in cows that did not ovulate. The objectives of Exp. 2 were 1) to determine whether a follicular wave could be synchronized in anestrous cows following injection of 1 mg of estradiol benzoate (EB) and 200 mg of progesterone (P4; EB + P4); 2) to characterize the fate of dominant follicles following 48-h CR at three stages of a synchronized follicular wave; and 3) to determine whether estrous cycles of normal length followed ovulation in cows pretreated with EB + P4. Ovaries of 50 anestrous beef cows were examined daily as in Exp. 1. Treatments were sesame oil (SO) injected (i.m.) on d 25 postpartum and no CR (n = 9); EB + P4 and no CR (n = 9); EB + P4 and CR on 6 (n = 12), 8 (n = 9), or 12 (n = 11) d after injection. The EB and P4 injections were given on d 25 postpartum. Variability in day of emergence of subsequent follicular waves was lower in cows receiving EB + P4 than in SO-injected cows (P < 0.05). The percentage of cows that ovulated was not different (P = 0.16), but CR increased the percentage of cows that ovulated when groups that received EB + P4 were compared to the EB + P4 group that did not have CR (53.1 vs 11.1%, respectively; P < 0.05). Maximum diameter of dominant follicles was larger (P = 0.05) in ovulatory follicles. The luteal phase was longer (P < 0.03) in cows receiving EB + P4 injection (10.6 +/- 1.2 d) than in cows receiving SO (4.4 +/- 2.2 d). In summary, the maximum size of ovulatory follicles was greater than that of nonovulatory follicles, the ovulatory response of postpartum anestrous cows was maintained through d 8 of a follicular wave, synchronization of follicular waves was accomplished in postpartum cows using EB + P4, and the subsequent luteal phase length was increased in animals that were administered EB + P4.
Asunto(s)
Bovinos/fisiología , Estradiol/análogos & derivados , Estradiol/administración & dosificación , Sincronización del Estro/efectos de los fármacos , Folículo Ovárico/fisiología , Progesterona/administración & dosificación , Anestro , Animales , Animales Lactantes , Esquema de Medicación , Femenino , Folículo Ovárico/diagnóstico por imagen , Inducción de la Ovulación/veterinaria , Periodo Posparto , Factores de Tiempo , Ultrasonografía , DesteteAsunto(s)
Dipeptidil Peptidasa 4/metabolismo , Compuestos Organofosforados/aislamiento & purificación , Compuestos Organofosforados/farmacología , Piperidonas/aislamiento & purificación , Piperidonas/farmacología , Inhibidores de Proteasas/aislamiento & purificación , Inhibidores de Proteasas/farmacología , Streptomyces/metabolismo , Espectroscopía de Resonancia Magnética , Estructura Molecular , Compuestos Organofosforados/química , Compuestos Organofosforados/metabolismo , Piperidonas/química , Piperidonas/metabolismo , Inhibidores de Proteasas/química , Inhibidores de Proteasas/metabolismo , Streptomyces/crecimiento & desarrolloRESUMEN
When methods of drug intervention are being developed to control estrous cycles, a thorough understanding of the endocrine and functional changes together with the reproductive behavior of the animals are essential. This review presents our current knowledge on reproductive endocrinology, physiology and behavior, and the methods of drug intervention to control estrous cycles. It also describes current efforts to develop advanced drug delivery systems that meet the animal scientist's demands to control the estrous cycle in cattle.
Asunto(s)
Bovinos/fisiología , Sistemas de Liberación de Medicamentos , Estro/efectos de los fármacos , Animales , Dinoprost/farmacología , Estro/fisiología , Femenino , Hormona Luteinizante/metabolismo , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , Pregnenodionas/farmacología , Progesterona/farmacología , Progestinas/farmacología , Maduración SexualRESUMEN
The objective of the experiment was to examine the interaction of endophyte-infected tall fescue and environmental temperature on follicular and luteal development and function in beef heifers. Heifers were fed endophyte-free or endophyte-infected tall fescue seed at thermoneutral or heat stress temperatures (n = 6/treatment) 4 wk before and 3 wk after synchronized ovulation. All heifers were subjected to thermoneutral conditions (19 degrees C, 50% relative humidity) from Days -7 to -2; temperature increased incrementally from Days -1 to 0 and cycled between 25 degrees C and 31 degrees C between Days 1 and 20 for heat-stressed heifers. Serum was collected and ovaries monitored every other day after induced luteolysis between Days 1 and 23 or until ovulation. Size and location of follicles >4 mm and corpora lutea were recorded. Serum concentrations of prolactin were reduced in heat-stressed heifers fed infected seed and both heat stress and infected seed decreased total cholesterol. Rectal temperature and respiration rate were greatest in heifers fed the infected seed when exposed to maximal temperatures. Heat stress led to reduced diameter of the corpus luteum and serum progesterone compared with thermoneutral conditions. Progesterone was reduced more so in heifers fed infected seed. The combination of infected seed and heat stress was associated with reduced diameter of the preovulatory dominant follicle, and consumption of infected seed led to fewer large follicles during the estrous cycle. Both stressors led to reduced serum estradiol. Impaired follicle function may explain reduced pregnancy rates commonly observed in heifers grazing infected tall fescue pasture.
Asunto(s)
Alimentación Animal/efectos adversos , Trastornos de Estrés por Calor/fisiopatología , Ovario/fisiopatología , Enfermedades de las Plantas , Animales , Temperatura Corporal/efectos de los fármacos , Bovinos , Colesterol/sangre , Dieta , Estradiol/sangre , Estro/efectos de los fármacos , Femenino , Contaminación de Alimentos , Folículo Ovárico/fisiología , Progesterona/sangre , Prolactina/sangre , Mecánica Respiratoria/efectos de los fármacosRESUMEN
The relationships between structures and inhibitory activities of glycosidase inhibitors of gem-diamine 1-N-iminosugars in media of enzyme assays have been investigated. It has been proved that gem-diamine 1-N-iminosugar smoothly undergoes a structural change to a hydrated ketone or its derivative via a hemiaminal in the media (pH 5.0-6.3), and that the products generated in the media as well as the parent gem-diamine 1-N-iminosugars potently inhibit glycosidases.
Asunto(s)
Metabolismo de los Hidratos de Carbono , Inhibidores Enzimáticos/metabolismo , Glicósido Hidrolasas/metabolismo , Cetonas/metabolismo , alfa-L-Fucosidasa/metabolismo , Animales , Carbohidratos/química , Carbohidratos/farmacología , Diaminas/química , Inhibidores Enzimáticos/farmacología , Glicósido Hidrolasas/antagonistas & inhibidores , Concentración de Iones de Hidrógeno , Iminas/química , Cetonas/química , Cetonas/farmacología , Relación Estructura-Actividad , Factores de Tiempo , alfa-L-Fucosidasa/antagonistas & inhibidoresRESUMEN
Ascorbic acid has three known functions: it is necessary for collagen synthesis, promotes steroidogenesis and acts as an antioxidant. Within the ovary, most studies have concentrated on the role of ascorbic acid in luteal formation and regression and little is known about the function of this vitamin in follicular growth and development. Follicular growth and development were investigated in this study using an individual follicle culture system that allows the growth of follicles from the late preantral stage to Graafian morphology. Follicles were isolated from prepubertal mice and cultured for 6 days. Control media contained serum and human recombinant FSH. Further groups of follicles were cultured in the same media but with the addition of ascorbic acid at concentrations of either 28 or 280 micromol l(-1). Addition of ascorbic acid at the higher concentration significantly increased the percentage of follicles that maintained basement membrane integrity throughout culture (P < 0.001). Ascorbic acid had no effect on the growth of the follicles or on oestradiol production. Metalloproteinase 2 activity tended to increase at the higher concentration of ascorbic acid and there was a significant concomitant increase in the activity of tissue inhibitor of metalloproteinase 1 (P < 0.01). Follicles cultured without the addition of serum but with FSH and selenium in the culture media underwent apoptosis. Addition of ascorbic acid to follicles cultured under serum-free conditions significantly reduced apoptosis (P < 0.05). From these data it is concluded that ascorbic acid is necessary for remodelling the basement membrane during follicular growth and that the ability of follicles to uptake ascorbic acid confers an advantage in terms of granulosa cell survival.