RESUMEN
This study assessed morphometric traits of the ampulla of the oviducts in prepubertal gilts treated with chorionic gonadotropins. With the day of slaughter as D0, gilts were assigned to four treatments (n = 8 each): control (untreated), eCG (200 IU eCG on D3), eCG+hCG (1200 IU eCG on D6 plus 500 IU hCG on D3), and eCG+hCG+AI (the previous treatment plus artificial insemination on D1). Blood and ampullae samples were collected at slaughter. Serum progesterone concentrations were higher for gilts treated with hCG than for those in the eCG and control treatments (p < 0.001), but estradiol concentrations did not differ (p > 0.05). The epithelium, muscle and lumen areas and the inner and larger ampullae diameters did not differ across treatments (p > 0.05). Therefore, treatment with chorionic gonadotropins did not alter the ampullae morphometry of prepubertal gilts.
Asunto(s)
Gonadotropina Coriónica , Estradiol , Inseminación Artificial , Progesterona , Maduración Sexual , Animales , Femenino , Gonadotropina Coriónica/farmacología , Gonadotropina Coriónica/administración & dosificación , Progesterona/sangre , Progesterona/farmacología , Estradiol/sangre , Estradiol/farmacología , Maduración Sexual/efectos de los fármacos , Inseminación Artificial/veterinaria , Porcinos , Sus scrofaRESUMEN
Hormonal protocols based on progestogens and equine chorionic gonadotrophin (eCG) are efficient for estrus and ovulation synchronization in ewes. Although eCG is indispensable during seasonal anestrus, it may not be necessary during the breeding season. Thus, we tested the hypothesis that GnRH is effective in replacing eCG during the breeding season allowing satisfactory ovulation rate, luteal function and conception rates after timed artificial insemination (TAI). Ewes (n = 134) with a minimum body condition score of 2.5 (0-5 scale) were treated with intravaginal devices (IVD) containing 60 mg of medroxyprogesterone acetate (MPA) for seven days and received 0.26 mg of sodium cloprostenol at the time of IVD removal. In Exp. 1, at IVD removal, ewes (n = 29) were allocated to three groups: eCG (200 IU at IVD removal; n = 10); eCG+GnRH (200 IU eCG at IVD removal and 4 µg of buserelin 36 h later; n = 10); or GnRH (buserelin 36 h after IVD removal; n = 9). Blood samples were collected 2, 6 and 12 days after TAI moment (54 h after IVD removal), for progesterone (P4) analysis. In Exp 2, the ewes were allocated to eCG (n = 10) or GnRH (n = 10) groups, as above described, and ovulation moment was evaluated 54, 66 and 78 h after IVD removal. In Exp 3, TAI was performed in ewes from eCG (n = 45) and GnRH (n = 40) groups using 100 × 106 motile spermatozoa from a pool of semen collected from four rams. In Exp. 1, based on P4 levels, we confirmed that all the ewes ovulated (29/29) and there was no significant effect of group (P = 0.89) or group x day (P = 0.18) on P4 concentration, being observed a significant effect of day (P = 0.0001). In Exp. 2, the maximum DF diameter (P = 0.26) and ovulation moment (P = 0.69) did not differ between groups. In Exp. 3, pregnancy rate was significantly lower (P = 0.02) in GnRH (22.5 %; 9/40) compared to eCG (46.7 %; 21/45). The results indicate that, although ovulation and luteal function were not altered after eCG, eCG+GnRH or GnRH treatment, GnRH alone before TAI cannot be used to replace eCG treatment during the breeding season.
Asunto(s)
Gonadotropina Coriónica , Sincronización del Estro , Hormona Liberadora de Gonadotropina , Inseminación Artificial , Animales , Femenino , Inseminación Artificial/veterinaria , Hormona Liberadora de Gonadotropina/farmacología , Hormona Liberadora de Gonadotropina/administración & dosificación , Ovinos/fisiología , Gonadotropina Coriónica/farmacología , Gonadotropina Coriónica/administración & dosificación , Embarazo , Sincronización del Estro/métodos , Progesterona/sangre , Progesterona/farmacología , Progesterona/administración & dosificación , Estaciones del Año , Acetato de Medroxiprogesterona/administración & dosificación , Acetato de Medroxiprogesterona/farmacología , Ovulación/efectos de los fármacos , Ovulación/fisiología , Gonadotropinas Equinas/farmacología , Gonadotropinas Equinas/administración & dosificaciónRESUMEN
Two experiments were performed to evaluate the effects of GnRH treatment on the fertility of suckled Nelore beef cows treated with an estradiol/progesterone (E2/P4)-based protocol for timed artificial insemination (TAI). Experiment 1 focused on determining the effects of estradiol cypionate (EC) on ovulation in TAI cows treated with GnRH 34 h after removal of the intravaginal P4 device (IPD). Suckled cows (n = 26) were treated with 2 mg estradiol benzoate (EB) and IPD containing 1 g P4. After 8 days, IPDs were removed, and all cows were treated with 150 µg of d-cloprostenol (prostaglandin F2 alpha analog) and 300 IU of equine chorionic gonadotropin (eCG), then separated into two treatment groups consisting of cows who received 1) saline 0.9% i.m. (GnRH34 group) or 2) 0.6 mg i.m. of EC (EC-GnRH34 group). On day 9 (05:00 p.m.), all cows were given GnRH (10.5 µg of buserelin acetate) i.m. No differences were observed between the groups (P > 0.05) in the time of ovulation after IPD removal or in the proportion of cows ovulating. Experiment 2 focused on determining the effects of GnRH34 along with or in the absence of EC on day 8 on pregnancy per AI (P/AI) in postpartum beef cows. Cows (n = 981) were treated similarly to those in Experiment 1, but an additional group, the EC-GnRH48 group, was included, in which cows received EC on day 8 whereas those that did not show estrus received GnRH at TAI. Thus, in this experiment, groups consisted of GnRH34 (n = 322), EC-GnRH34 (n = 335), and EC-GnRH48 (n = 324). A higher rate of estrus expression was observed in cows treated with EC following IPD removal (EC-GnRH34: 69%, EC-GnRH48: 64.8%) than in cows in the GnRH34 group (45.6%). No difference in P/AI was observed between the treatment groups (P = 0.45), but P/AI in cows in the EC-GnRH34 group (64.2%) tended to be greater (P = 0.1) than in cows in the GnRH34 group (58%). In summary, although ovulation synchrony did not differ among the groups, P/AI in cows treated with EC and GnRH 34 h after IPD removal tended to be greater than in cows treated solely with GnRH; this was most likely due to a shorter proestrus/estrus period, considering the lower proportion of cows that displayed estrus in the GnRH34 group. Finally, given that P/AI did not differ between the EC-GnRH34 and EC-GnRH48 groups, our results suggest that, for cows not displaying estrus, administration of EC at the time of IPD removal followed by treatment with GnRH 48 h afterward represents the most cost-efficient TAI strategy for South American Zebu-based beef operations.
Asunto(s)
Estradiol , Progesterona , Embarazo , Femenino , Bovinos , Animales , Caballos , Progesterona/farmacología , Estradiol/farmacología , Hormona Liberadora de Gonadotropina/farmacología , Buserelina , Inseminación Artificial/veterinaria , Inseminación Artificial/métodos , Sincronización del Estro/métodosRESUMEN
A protocol to induce lactation was applied to non-pregnant gilts. In Experiment I, five gilts with oestrus synchronized through oral supplementation of 20 mg altrenogest for 18 days received: 10 mg oestradiol cypionate (EC) on the last day of oestrous expression (D0); 10 mg EC and 300 mg long-acting progesterone (P4) on D26; and two 0.53 mg doses of a prostaglandin F2α analogue (PGF) 12 h apart on D36. Blood was collected on D12, D19, D26 and D33. Milk secretion started in all gilts 24 h after PGF administration and lasted at least 8 days. Milk samples were collected from D37 to D45. The serum P4 concentration was lower on D12 than subsequently (p < .05), but the oestradiol concentration was unaltered (p > .05). The milk produced during the induced lactation was generally richer in protein and poorer in fat compared to the milk from the lactation of a reference sow. In Experiment II, the same protocol induced lactation in two gilts, which nursed fostered piglets for 22 days. Thus, lactation was induced in all treated gilts and the milk produced was capable to nurture fostered piglets.
Asunto(s)
Lactancia , Progesterona , Animales , Porcinos , Femenino , Sus scrofa/metabolismo , Estro , LecheRESUMEN
Oocyte-derived bone morphogenetic protein 15 (BMP15) is one of the main local regulators of ovarian physiology, but its role in the regulation of preovulatory follicles and ovulation is not well established. Therefore, this study was conceived to determine the effect of intrafollicular injection (IFI) of BMP15 on final follicular growth, ovulation and luteinization in cattle. Initially, it was observed that relative mRNA abundance of the BMP15 receptor BMPR1B in granulosa cells was regulated by GnRH treatment, and it was negatively correlated (R2 = 0.5; P < 0.001) to progesterone concentration in follicular fluid (FF) from preovulatory follicles. The IFI of recombinant human BMP15 tended to inhibit the growth of dominant follicles, as evidenced by an average increase of only 7.7% in the follicular diameter (from 8.8 mm to 9.1 mm) at 36 h post injection compared to 36.4% increase (from 8.9 mm to 14 mm) in the control group. Injection of BMP15 into preovulatory follicles (12-14 mm), simultaneously to im GnRH treatment, inhibited ovulation compared to control group, but did not prevent luteinization and progesterone production. Most of preovulatory follicles injected with BMP15 became luteinized cysts. Collectively, these findings indicate a suppressive role of BMP15 on later follicular development and ovulation in cattle, but not on luteogenesis and progesterone secretion.
Asunto(s)
Proteína Morfogenética Ósea 15 , Folículo Ovárico , Animales , Proteína Morfogenética Ósea 15/metabolismo , Bovinos , Femenino , Células de la Granulosa/metabolismo , Folículo Ovárico/fisiología , Ovulación , Progesterona/farmacologíaRESUMEN
Lipopolysaccharide (LPS) endotoxemia has been negatively associated with fertility. This study aimed to investigate the effect of LPS-induced inflammation on gene expression associated with bovine fertility in the uterus and oviduct. Sixteen healthy heifers were divided into two groups. The LPS group (n = 8) received two intravenous (i.v.) injections of 0.5 µg/kg of body weight of LPS with a 24-h interval, and the control group (n = 8) received two i.v. injections of saline solution with the same interval of time. All the animals had the follicular wave synchronized. Three days after the second injection of LPS, all animals were slaughtered and uterine and oviduct samples were collected. Gene expression associated with inflammatory response, thermal and oxidative stresses, oviduct environment quality, and uterine environment quality was evaluated. Body temperature and leucogram demonstrated that LPS induced an acute systemic inflammatory response. In the uterus, the expression of PTGS2 and NANOG genes was downregulated by the LPS challenge. However, no change in expression was observed in the other evaluated genes in the uterus, nor those evaluated in the oviduct. In conclusion, the inflammatory process triggered by LPS did not persist in the uterus and oviduct 3 days after challenge with LPS. Nonetheless, reduction in PTGS2 and NANOG expression in the uterus suggested that, indirectly, LPS may have a prolonged effect, which may affect corpus luteum and endometrial functions.
Asunto(s)
Bovinos , Fertilidad , Oviductos , Útero , Animales , Bovinos/genética , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/metabolismo , Femenino , Fertilidad/genética , Lipopolisacáridos/farmacología , Oviductos/metabolismo , Útero/metabolismoRESUMEN
Regulation of the transforming growth factor beta (TGFß) superfamily by gonadotrophins in swine follicular cells is not fully understood. This study evaluated the expression of steroidogenic enzymes and members of the TGFß superfamily in prepubertal gilts allocated to three treatments: 1200 IU eCG at D -3 (eCG); 1200 IU eCG at D -6 plus 500 IU hCG at D -3 (eCG + hCG); and the control, composed of untreated gilts. Blood samples and ovaries were collected at slaughter (D0) and follicular cells were recovered thereafter. Relative gene expression was determined by real-time PCR. Serum progesterone levels were greater in the eCG + hCG group compared with the other groups (P < 0.01). No differences were observed in the expression of BMP15, BMPR1A, BMPR2, FSHR, GDF9, LHCGR and TGFBR1 (P > 0.05). Gilts from the eCG group presented numerically greater mean expression of CYP11A1 mRNA than in the control group that approached statistical significance (P = 0.08) and greater expression of CYP19A1 than in both the eCG and the control groups (P < 0.05). Expression of BMPR1B was lower in the eCG + hCG treatment group compared with the control (P < 0.05). In conclusion, eCG treatment increased the relative expression of steroidogenic enzymes, whereas treatment with eCG + hCG increased serum progesterone levels. Although most of the evaluated TGFß members were not regulated after gonadotrophin treatment, the downregulation of BMPR1B observed after treatment with eCG + hCG and suggests a role in luteinization regulation.
Asunto(s)
Gonadotropina Coriónica , Folículo Ovárico/citología , Proteínas de la Superfamilia TGF-beta/metabolismo , Animales , Gonadotropina Coriónica/farmacología , Femenino , Progesterona , PorcinosRESUMEN
Two experiments evaluated the effects of gonadotropin releasing hormone (GnRH) treatment on fertility of suckled Nelore beef cows treated with an estradiol/progesterone (P4)-based protocol for timed artificial insemination (TAI). Experiment 1 was designed to determine the effect of GnRH administered 34 h after P4 insert removal (GnRH34) on time of ovulation. Suckled cows (n = 34) were treated with 2 mg estradiol benzoate (EB) and an intravaginal insert containing 1.9 g of P4. Eight days later, P4 inserts were removed, and all cows received 150 µg of d-cloprostenol (prostaglandin F2 alpha analogue), 300 IU of eCG, and 1 mg of estradiol cypionate (ECP). On Day 9 (05:00 p.m.), cows were randomly distributed, according to the diameter of the pre-ovulatory follicle, in two treatments: 1) GnRH (n = 17) cows that received 10.5 µg of buserelin acetate, or 2) no further treatment (control, n = 17). Cows treated with GnRH 34 h after P4 insert removal ovulated earlier (P = 0.02) than control cows (66 ± 0.0 and 77.2 ± 4.3 h). Experiment 2 was designed to determine the effect of GnRH34 on the fertility of suckled beef cows. Nelore cows (n = 506) were treated as Experiment 1. On Day 8, cows were painted in the sacrocaudal region to identify cows that displayed estrus. On Day 9 (05:00 p.m.), cows were randomized to receive same treatment as Experiment 1, control (n = 252), or GnRH (n = 254). All cows were TAI 48 h after P4 insert removal. At TAI, estrus was evaluated, and deemed to have occurred in cows without a tail-head chalk mark (>75% paint loss). Cows treated with GnRH 34 h after P4 insert removal had greater (P = 0.01) pregnancy per AI (P/AI) than cows that only received ECP (63.0% and 50.4%). No difference (P = 0.5) was observed in the proportion of cows that displayed estrus between treatments. Furthermore, cows that displayed estrus had greater (P < 0.01) P/AI than cows that did not. Treatment with GnRH, given at 34 h after P4 insert removal, increased (P < 0.05) P/AI in cows that did not show estrus at TAI. In summary, treatment with GnRH 34 h after P4 insert removal was associated with earlier ovulation and resulted in greater P/AI in suckled Nelore cows treated with an estradiol/P4-based protocol for TAI.
Asunto(s)
Inseminación Artificial , Progesterona , Animales , Buserelina , Bovinos , Dinoprost , Estradiol , Estro , Sincronización del Estro , Femenino , Hormona Liberadora de Gonadotropina/farmacología , Inseminación Artificial/veterinaria , Lactancia , EmbarazoRESUMEN
Although it is well documented that leptin signals the body nutritional status to the brain, mechanisms of leptin regulation at the ovary are not well understood. This study was conducted to determine whether there was leptin and the receptor for leptin (LEPR) in cattle ovarian follicles and to investigate potential actions of leptin on follicular growth in vivo and on regulation of granulosa cell functions in vitro. There was leptin and LEPR in granulosa and theca cells of dominant and subordinate follicles, with greater immunostaining for leptin in granulosa cells of subordinate follicles. There was a lesser relative abundance of leptin receptor gene-related protein (LEPROT) and of the adiponectin receptors 1 (ADIPOR1) and 2 (ADIPOR2) mRNA transcripts in granulosa cells of subordinate than dominant follicles (P < 0.05). Intrafollicular injection of either 100 or 1000 ng/mL leptin did not affect the diameter and the growth of dominant follicles (P> 0.05). Supplementation of in vitro culture medium with different leptin concentations did not affect (P > 0.05) the relative abundance of hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 (HSD3B1), cytochrome P450 family 11 subfamily A member 1 (CYP11A1), signal transducer and activator of transcription 3 (STAT3) and X-linked inhibitor of apoptosis protein (XIAP) mRNA transcripts in granulosa cells. These findings indicate that leptin and LEPR are present in the follicular cells of cattle ovaries, but leptin apparently does not have essential functions in steroidogenesis and growth of dominant follicles.
Asunto(s)
Regulación de la Expresión Génica/efectos de los fármacos , Leptina/metabolismo , Leptina/farmacología , Folículo Ovárico/metabolismo , Animales , Bovinos , Femenino , Regulación de la Expresión Génica/fisiología , Leptina/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Adiponectina/genética , Receptores de Adiponectina/metabolismo , Receptores de Leptina/genética , Receptores de Leptina/metabolismoRESUMEN
OBJECTIVE: To analyse the Na content of bread by comparing the amount of salt and Na among the label, laboratory analysis and international guidelines. DESIGN: Ten selected bakeries provided 3239 randomly selected samples of bread, which were weighed on-site. Triplicate samples were retrieved from each bakery (thirty samples) for analysis. Bread production was observed, and ingredient labels were queried to determine salt weights, which were used for comparison with the laboratory analysis. Flame photometry and the method for chlorides were utilised for analysing Na. Laboratory findings were compared to nine different international nutritional guidelines for Na consumption. SETTING: Florianopolis, south of Brazil. PARTICIPANTS: Ninety independent bakeries locally producing Portuguese rolls were queried; rolls from ten conveniently selected bakeries were retrieved for further analysis. RESULTS: The average weight of the rolls was 50·2 ± 5·3 g. The average amount of salt (g) per roll, by laboratory and label analyses, was 0·69 ± 0·0 and 0·62 ± 0·1 g, respectively. The mean level of Na (mg) reported on nutrient labels (478·2 ± 93·4/100 g) was significantly lower than by laboratory analysis (618·2 ± 73·8/100 g), P < 0·001. There was a difference for Na in rolls produced in the bakeries considering the unit weight of rolls (P ≤ 0·001) per 100 g (P = 0·026) and the mode of production. The consumption of two averaged units of rolls was equivalent to 51·7 % of the Brazilian guideline daily amount for Na for children and 31 % for adults. CONCLUSIONS: The nutrient labels underreported Na values. This study strengthens the importance of monitoring Na of breads in Brazil.
Asunto(s)
Laboratorios , Sodio , Adulto , Brasil , Niño , Análisis de los Alimentos , Humanos , PortugalRESUMEN
Dairy cows frequently undergo a state of negative energy balance (NEB) after parturition and some have impaired ovarian functions that result in delayed resumption of estrous cyclicity and development of follicles without ovulation occurring. During the postpartum period, cows undergo body-fat store losses, hormonal changes, fat mobilization and increases in nonesterified fatty acid (NEFAs) concentrations in blood and follicular fluid. The effect of NEFAs on follicular development and function of follicular cells, however, is not fully understood. The aim of this study, therefore, was to study the effect of an intrafollicular injection of a mixture of oleic, stearic and palmitic NEFAs on dominant follicle development and function of granulosa cells in cows that were not in a NEB state. Follicular size was less at 24 and 48â¯h after administration of NEFAs compared to that of control follicles injected with vehicle only. At 24â¯h after intrafollicular injection, the relative mRNA transcript abundance for proteins involved in steroidogenesis (CYP19A1, 3BHSD, STAR, FSHR), metabolism (GLUT1, GLUT3, INSR, IRS1, IRS2, SLC27A1, PPARG), and cell proliferation and apoptosis (CCND2; XIAP) in granulosa cells, as well as estradiol concentrations in follicular fluid were similar in control and NEFA-treated follicles. In conclusion, the results of this study indicate increased intrafollicular concentrations of NEFAs in cows that are not in a NEB state has a detrimental effect on follicle development. We propose intrafollicular injection is a useful approach to further investigate the local effects of NEFAs on the function of follicular cells.
Asunto(s)
Bovinos , Ácidos Grasos no Esterificados/farmacología , Folículo Ovárico/efectos de los fármacos , Ovulación/efectos de los fármacos , Animales , Aromatasa/genética , Aromatasa/metabolismo , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/fisiología , Sincronización del Estro/efectos de los fármacos , Sincronización del Estro/fisiología , Ácidos Grasos no Esterificados/administración & dosificación , Femenino , Líquido Folicular/efectos de los fármacos , Líquido Folicular/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Células de la Granulosa/citología , Células de la Granulosa/efectos de los fármacos , Células de la Granulosa/metabolismo , Inyecciones , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/fisiología , Oogénesis/efectos de los fármacos , Oogénesis/genética , Folículo Ovárico/fisiología , Ovariectomía/veterinaria , Ovulación/genética , Ovulación/metabolismo , ARN Mensajero/metabolismoRESUMEN
The peroxisome proliferator-activated receptor gamma (PPARG, also called NR1C3) is a nuclear receptor of the peroxisome proliferator-activated receptor family (PPAR). PPARs are involved in the regulation of apoptosis, cell cycle, estradiol and progesterone synthesis, and metabolism. However, the role of PPARs and their regulation during follicular development and ovulation in monovular species remain poorly understood. In this study, a well-established intrafollicular injection model was used to investigate if the PPARG participates in the regulation of dominant follicle development and ovulation in cattle. Findings from this study revealed that the relative mRNA abundance of PPARG was similar between dominant and subordinate follicles around follicle deviation, decreased after the LH surge, and increased before ovulation. In addition, a quadratic correlation was found between PPARG mRNA levels in granulosa cells and progesterone concentration in the follicular fluid. Intrafollicular injection of 50⯵M Troglitazone (TGZ; a PPARG agonist) inhibited follicular growth and decreased CYP19A1 mRNA abundance in granulosa cells. These findings indicate that PPARG is involved in the regulation of steroidogenesis, follicle growth and ovulation in cattle.
Asunto(s)
Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , PPAR gamma/agonistas , Troglitazona/farmacología , Animales , Bovinos , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Femenino , Expresión Génica/efectos de los fármacos , Células de la Granulosa/efectos de los fármacos , Células de la Granulosa/fisiología , Oogénesis/efectos de los fármacos , Oogénesis/genética , Ovulación/efectos de los fármacos , Ovulación/genética , PPAR gamma/genética , PPAR gamma/metabolismoRESUMEN
Omega-3 PUFA may benefit sow reproductive performance, but effects on weaned gilts are unknown. This study evaluated the effects of supplementing omega-3 PUFA to gilts after weaning on growth, metabolic markers, and gene expression of steroidogenic enzymes and hormone receptors. For 52 d, gilts in the control group were fed 100 g/d of regular diets, whereas gilts in the omega-3 group were fed 75 g/d of such diets plus 25 g/d of the microalgae Schizochytium sp. (3.5 g/d of omega-3 PUFA; n = 8 gilts/group). Blood samples were collected at day 0, day 21, and day 52. Total serum cholesterol levels were lower for the omega-3 group than for the control group (P < 0.05), but high-density lipoprotein-cholesterol levels were reduced at day 52 for both groups (P < 0.05). Gilts in the omega-3 group presented lower feed intake, better feed conversion, and less-intense immunolabeling for leptin and its receptor in the cytoplasm of oocytes included in primordial/primary follicles than gilts in the control group (P < 0.05). The expression of genes coding for cholesterol side-chain cleavage and aromatase enzymes and the LH receptor in follicular cells was lower for supplemented gilts (P < 0.05). Compared with controls, supplemented gilts presented decreased serum cholesterol levels and better feed conversion, but leptin presence and gene expression for steroidogenic enzymes and for the LH receptor were lower at ovarian level.
Asunto(s)
Alimentación Animal/análisis , Dieta/veterinaria , Ácidos Grasos Omega-3/farmacología , Ovario/efectos de los fármacos , Porcinos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Femenino , Expresión Génica/efectos de los fármacos , Leptina/metabolismo , Ovario/metabolismoRESUMEN
Oncostatin M (OSM) and its receptor (OSMR) are members of the interleukin-6 family cytokines. Although OSM and OSMR expression was detected in human ovaries, their function and regulation during follicle development, ovulation and luteolysis have not been studied in any species. The aim of the present study was to investigate the levels of OSM and OSMR mRNA in bovine ovaries and the effect of OSM treatment on cultured granulosa cells. OSM mRNA was not detected in granulosa cells obtained from follicles around the time of follicular deviation and from pre-ovulatory follicles, whereas OSMR transcript levels were greater in granulosa cells of atretic subordinate follicles (P < 0.001). Abundance of OSMR mRNA increased in granulosa cells of preovulatory follicles, collected at 12 and 24 h after the ovulatory stimulus with gonadotropins (P < 0.001). In the luteal tissue, OSM mRNA abundance levels were higher at 24-48 h after PGF-induced luteolysis (P < 0.01) compared to 0 h, whereas OSMR mRNA was transiently increased at 2 h after PGF treatment (P < 0.05). In cultured granulosa cells, 10 ng/mL OSM in the presence of FSH increased BAX/BCL2 mRNA ratio (P < 0.05) compared to the control. Moreover, 100 ng/mL OSM in the presence of FSH increased OSMR (P < 0.05) and decreased XIAP mRNA (P < 0.05) levels, compared to the control group. These findings provide the first evidence that OSMR is regulated during follicle atresia, ovulation and luteolysis, and that OSM from other cells may mediate granulosa and luteal cell function, regulating the expression of genes involved in cell's viability.
Asunto(s)
Regulación de la Expresión Génica/fisiología , Células de la Granulosa/metabolismo , Células Lúteas/metabolismo , Oncostatina M/metabolismo , ARN Mensajero/metabolismo , Receptores de Oncostatina M/metabolismo , Animales , Bovinos , Células Cultivadas , Femenino , Luteólisis/fisiología , Oncostatina M/genética , Ovulación/fisiología , ARN Mensajero/genética , Receptores de Oncostatina M/genéticaRESUMEN
During folliculogenesis, the luteinizing hormone (LH) surge triggers dynamic events in granulosa cells that culminate with ovulation. The aim of this study was to evaluate if the epidermal growth factor receptor (EGFR) is required for ovulation in cattle, and if it regulates the expression of the natriuretic peptide (NP) system in granulosa cells after gonadotropin-releasing hormone (GnRH)/LH stimulation. It was observed that GnRH induces amphiregulin (AREG) and epiregulin (EREG) mRNA at 3 and 6â¯h after in vivo treatment, but the expression of these genes was not regulated by atrial (ANP) and C-type (CNP) NPs in granulosa cells cultured in vitro. The abundance of mRNA encoding the NP receptors (NPR1, 2 and 3) was not altered by LH supplementation and/or EGFR inhibition (AG1478; AG) in granulosa cells after 6â¯h of in vitro culture. However, in the same conditions, mRNA encoding the natriuretic peptide precursor C (NPPC) was upregulated by LH, whereas AG (0.5 and 5⯵M) inhibited the LH effect. In order to confirm those results, 5⯵M AG or saline were intrafollicularly injected in preovulatory follicles and cows were simultaneously treated with GnRH intramuscularly. Granulosa cells harvested at 6â¯h after GnRH injection revealed higher NPR3 and lower NPPC mRNA levels in AG-treated, compared to control cows. However, intrafollicular injection of AG did not inhibit GnRH-induced ovulation. In granulosa cells cultured in vitro, ANP associated with LH increased prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA abundance. In conclusion, we inferred that LH modulated NPPC and NPR3 mRNA abundance through EGFR in bovine granulosa cells, but ovulation in cattle did not seem to depend on EGFR activation.
Asunto(s)
Bovinos , Regulación de la Expresión Génica/efectos de los fármacos , Células de la Granulosa/efectos de los fármacos , Hormona Luteinizante/farmacología , Receptores del Factor Natriurético Atrial/metabolismo , Anfirregulina/metabolismo , Animales , Biomarcadores , Epirregulina/metabolismo , Receptores ErbB , Femenino , Células de la Granulosa/fisiología , ARN Mensajero , Receptores del Factor Natriurético Atrial/genética , Regulación hacia ArribaRESUMEN
Although fixed-time artificial insemination (FTAI) protocols are available for sheep, estrus resynchronization has not been previously reported. The objectives of this study were to evaluate the effect of estrus resynchronization with exogenous progestogen on endogenous progesterone levels and to compare pregnancy rates after two consecutive estrus synchronizations in ewes. In Experiment 1, ewes (n = 20) received an intravaginal device (IVD) containing 60 mg medroxyprogesterone acetate (MPA) for 10 days. At the IVD withdrawal (D0), ewes received 250 IU eCG and were allocated into two treatments: either no further treatment (Control; n = 10) or estrus resynchronization (Resynch; n = 10) from D12 to D19. Serum progesterone (P4) levels did not differ at D12 and D19 (P > 0.05), but were greater at D15 for the Control compared with the Resynch group (P < 0.05). In experiment 2, ewes (n = 250) were submitted to a first synchronization protocol followed by estrus detection and either artificial insemination (AI) or natural mating (NM). Subsequently, ewes were divided into two groups: Control (n = 104): which received no further treatment and were bred by NM; and Resynch (n = 146): which were submitted to a second synchronization starting on D14 (first IVD withdrawal = D0) and to NM after second IVD withdrawal (D20). Cumulative pregnancy rates did not differ between the Control (67.3%, 70/104) and Resynch (62.3%, 91/146) groups. In a third experiment, ewes (n = 83) were bred by two consecutive FTAI within a 20-day interval. Pregnancy rates after the first (30.1%, 25/83) and the second FTAI (36.2%, 21/58) did not differ (P > 0.05). In conclusion, although exogenous progestogen supplementation reduced circulating levels of P4, pregnancy maintenance was unaffected. Estrus resynchronization in ewes is feasible, resulting in similar fertility after the first and the second services. The use of resynchronization coupled with artificial insemination using semen from genetically superior rams may potentially accelerate genetic improvement in sheep herds by allowing a higher differential selection compared with natural breeding.
Asunto(s)
Gonadotropina Coriónica/farmacología , Sincronización del Estro/métodos , Animales , Gonadotropina Coriónica/administración & dosificación , Femenino , Inseminación Artificial/veterinaria , Acetato de Medroxiprogesterona/administración & dosificación , Acetato de Medroxiprogesterona/farmacología , Embarazo , Índice de Embarazo , OvinosRESUMEN
Prostaglandin F2α (PGF) induces the precipitous loss of steroidogenic capabilities and cellular death in the corpus luteum of many species, yet the molecular mechanisms underlying this event are not completely understood. Signal transducer and activator of transcription 3 (STAT3) was activated in granulosa cells during follicle atresia, whereas AKT is immediately down-regulated in the corpus luteum after PGF treatment in cattle; however, their involvement in both functional and morphological luteolysis in monovular species still need to be determined. Blood samples and corpus lutea were collected from cows before (0) and 2, 12, 24, and 48 hr after PGF treatment on Day 10 of the estrous cycle (4-5 cows per time point). Serum progesterone concentrations decreased by threefold (p < 0.05) within 2 hr, confirming functional luteolysis. The mRNA abundance of the pro-apoptotic gene BAX increased 12-48 hr post-PGF treatment (p < 0.05), while morphological luteolysis was observed 24 and 48 hr after PGF treatment, based on the loss of plasma membrane integrity, reduction of cytoplasmic volume, and pyknotic nuclei. Phosphorylated STAT3 increased, peaking at 12 hr, and remained elevated until 48 hr after PGF treatment. SOCS3 transcript abundance also increased (p < 0.05) starting at 2 hr post-PGF treatment. In contrast, AKT phosphorylation decreased by 12 hr after treatment. Thus, activation of STAT3 and inactivation of AKT signaling are involved in structural regression of the corpus luteum.
Asunto(s)
Cuerpo Lúteo/metabolismo , Dinoprost/farmacología , Luteólisis/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Bovinos , FemeninoRESUMEN
Intratesticular injection (ITI) of sodium chloride (NaCl) is efficient for chemical castration of young calves, but its effects on calves welfare are unknown. Two experiments were conducted to evaluate the effects of ITI of 20% NaCl on stress and inflammatory markers in calves less than 20 days old and to assess the efficiency of ITI of 30% NaCl in 5 months old calves. In Experiment 1, control calves were only restrained and compared to calves submitted to castration through surgery (SC) and ITI with 20% NaCl (n = 9/group). No differences were observed for the eye corner temperature measured by thermography from 60 s before to 60 s after the procedures (P > 0.05). In the SC group, acute serum cortisol levels increased at 30 and 60 min after the procedure, but increased levels in the ITI group occurred only at 30 min (P < 0.05). Chronic discomfort markers were measured at 0, 24, 48, 72 and 96 h after the procedures (D0, D1, D2, D3 and D4, respectively). The serum levels of the paraoxonase 1 (PON1) enzyme and cortisol did not differ among groups (P > 0.05). Scrotal temperature was higher at D1 in the SC group than for the other groups, but lowest at D4 compared to the control (both P < 0.05). In Experiment 2, histological sections of testes were compared after ITI with either 30% NaCl or 30% calcium chloride (CaCl2), to intact calves (control). After 60 days, intact seminiferous tubules and mediastinum were observed after ITI with 30% NaCl, whereas coagulative necrosis, inflammatory infiltration and calcification occurred after ITI with 30% CaCl2. Efficient chemical castration through ITI of 20% NaCl in young calves was followed by slight stress and inflammatory responses compared to surgical castration. However, ITI of 30% NaCl was ineffective for chemical castration of 5 months old calves.
Asunto(s)
Bovinos , Orquiectomía/veterinaria , Solución Salina Hipertónica/administración & dosificación , Animales , Arildialquilfosfatasa/sangre , Temperatura Corporal , Cloruro de Calcio/farmacología , Hidrocortisona/sangre , Masculino , Orquiectomía/métodos , Solución Salina Hipertónica/farmacología , Escroto/efectos de los fármacos , Escroto/fisiología , Testículo/efectos de los fármacos , Testículo/metabolismoRESUMEN
The increased incidence of fungal infections and the development of drug resistance have led to the search for microorganisms capable of producing bioactive metabolites with antifungal activity. Among these microorganisms, Streptomyces spp are distinguished mainly owing to their potential to secrete bioactive molecules. The aim of this study was to evaluate the production of secondary metabolites by Streptomyces sp TUR-10 against 12 fungal clinical isolates (yeast and filamentous fungi). In the preliminary screening, Streptomyces sp TUR-10 showed activity against 75% of the clinical isolates, and was selected for fermentation. In this assay, we tested three different media (MPE, M1, and ISP-4) for 96 h at pH 7.0 and 30°C for the production of bioactive metabolites. Increased production of bioactive compounds was observed when using the MPE medium for 48 h, with good activity against Candida pelliculosa. The minimum inhibitory concentration showed significant antifungal activity values ranging from 15.6 to 250 µg/mL. The actinobacterium was characterized by 16S rRNA analysis and the pattern suggested that the isolate studied belonged to the species Streptomyces ansochromogenes. The biotechnological potential of this strain was also demonstrated by the detection of the nrps and pks genes. These results indicate the production of secondary metabolites of biotechnological interest by actinobacteria from the rhizosphere, suggesting great potential for further research.