RESUMO
The study evaluates the effect of three hormonal protocols on ovarian dynamics and progesterone (P4) secretion of buffalo (Bubalus bubalis). Twenty-nine pluriparous Murrah buffaloes were used. The protocols were as follows: OVSYNCH (n = 10): 100 µg of gonadorelin (day 0), 500 µg of cloprostenol (day 7), and 100 µg of gonadorelin (day 9). CIDR+EB (intravaginal device (CIDR®) + estradiol benzoate; n = 10): CIDR plus 2 mg of EB (day 0), withdrew of CIDR, 500 µg of cloprostenol (day 7) and 1 mg of EB (day 8). CIDR+eCG (n = 9): CIDR plus 2 mg of EB (day 0), withdrew of CIDR, 500 µg of cloprostenol and 400 IU of eCG (day 7). Follicles were counted with an ultrasound and measured at 0, 24, and 54 h. The maximum follicle diameter and ovulation were evaluated at 70, 80, and 94 h after CIDR withdrew. Estrous was detected per 1 h three times daily. Blood samples were collected on days 0, 7, 10, 15, and 22 to determine P4 concentration. In CIDR+EB protocol, 50% of buffaloes presented estrous, at 69.6 h. All buffaloes ovulated. CIDR+eCG group had the shortest (69 h) ovulation time. No treatment differences for follicular population, maximum follicle diameter, and P4 concentration on days 7 and 10 (P > 0.05) were found. The P4 concentration in OVSYNCH and CIDR+eCG protocols were > 1 ng/ml, on days 15 and 22 (P < 0.05). There was no difference in ovarian activity; however, the P4 secretion was normal in the OVSYNCH and CIDR+eCG protocols compared to the CIDR+EB protocol.
Assuntos
Búfalos/fisiologia , Sincronização do Estro/métodos , Ovário/fisiologia , Progesterona/sangue , Progestinas/sangue , Animais , Cloprostenol/administração & dosagem , Estradiol/administração & dosagem , Estradiol/análogos & derivados , Estrogênios/administração & dosagem , Feminino , Hormônio Liberador de Gonadotropina/administração & dosagem , México , Progestinas/administração & dosagem , Distribuição AleatóriaRESUMO
OBJECTIVE: With the widespread use of sex-steroid hormones in contraceptives and hormone replacement therapy, there is an increasing need for reliable analytical methods. We report the development of a sensitive and robust UPLC-MS/MS method for quantitation of both endogenous and synthetic sex-steroid hormones in human serum. STUDY DESIGN: We developed and validated a UPLC-MS/MS method to quantify progestogens (etonogestrel, levonorgestrel, medroxyprogesterone acetate, norethindrone, progesterone) and estrogens (estradiol and ethinyl estradiol) with good accuracy, high sensitivity, and excellent robustness. We then applied the method to the analysis of sex-steroid hormones in serum from 451 clinical research participants. RESULTS: Each UPLC-MS/MS analysis was 6.5 min. The lower limits of quantitation (LLOQs) were 25 pg/ml for the progestogens, and 2.5 and 5.0 pg/ml for estradiol and ethinyl estradiol, respectively. When estradiol was analyzed without assessment of progestogens, the LLOQ was reduced to 1 pg/ml. The calibration curves were linear from 25-50,000, 2.5-2000 (1-2000 for estrogens-only analysis) and 5-2000 pg/ml, respectively. Both the accuracy and precision were below±15% not only for routine validation (intraday and interday), but for long-term (>2 years) assay robustness with external controls, thereby, demonstrating the utility of this method for multi-year clinical trial assessments of progestogens and estrogens. We applied the method to quantify sex-steroid levels in 1804 clinical samples. CONCLUSIONS: We successfully developed a UPLC-MS/MS method, and overcame the matrix suppression to allow sensitive quantitation of both synthetic and endogenous sex-steroid hormones in human serum. IMPLICATIONS: We developed a sensitive and robust UPLC-MS/MS method to accurately measure the levels of sex-steroid hormones in serum. The method overcame matrix interference barriers and achieved excellent long-term stability and reproducibility (≥96.9% accuracy; ≤13.0% relative variability measured with external controls over 2 years), demonstrating its utility in clinical sample analysis.
Assuntos
Cromatografia Líquida/métodos , Estrogênios/sangue , Espectrometria de Massas/métodos , Progestinas/sangue , Humanos , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: In rodents, progesterone (P4) pretreatment increases anxiety and response to stressors. Social isolation is a stressor that generates physiological and behavioural stress responses in sheep. The aim of the study was to compare the stress response of anoestrous ewes previously treated or not with P4 to the social isolation test. DESIGN: Ten ewes received P4 treatment during 13 d (group P4-W) and another 10 remained untreated as controls (group Con). The ewes were individually isolated in a novel place during 10 min, 24 h after the end of P4 pretreatment and their behaviours were recorded. Cortisol and P4 concentrations as well as body surface temperature were recorded before and after the test. RESULTS: Ewes of the P4-W group presented higher cortisol levels 0, 10, 20 and 30 min after the social isolation and had greater area under the curve of cortisol compared to Con ewes (41,785%±4,156% vs. 25,682%±4,565% during 75 min). Progesterone and body surface temperature increased after social isolation, with no differences between P4-W and Con ewes. There were no differences in behavioural responses to social isolation. CONCLUSIONS: P4 pretreatment appears to augment the stress response to social isolation in anoestrous ewes.
Assuntos
Progesterona/farmacologia , Progestinas/farmacologia , Ovinos/sangue , Isolamento Social , Estresse Fisiológico/efeitos dos fármacos , Animais , Temperatura Corporal , Esquema de Medicação , Feminino , Hidrocortisona/sangue , Progesterona/administração & dosagem , Progesterona/sangue , Progestinas/administração & dosagem , Progestinas/sangue , Ovinos/fisiologia , Estresse Fisiológico/fisiologiaRESUMO
OBJECTIVE: To determine the pain thresholds of women taking different formulations of hormonal contraceptives. DESIGN: Cross-sectional study. SETTING: Basic health care unit. PATIENT(S): Eighty-nine healthy nonusers and 188 users of hormonal contraceptives. INTERVENTION(S): Subject interviews were followed by the application of a semistructured questionnaire, including a psychometric assessment with the Beck Depression Inventory and the State-Trait Anxiety Inventory. After the interview, a 10-mL peripheral blood sample was collected. Pain thresholds were obtained by performing pressure algometry. MAIN OUTCOME MEASURE(S): Serum concentrations of E2, P, and T (free fraction) were determined via chemoluminescence. The menstrual cycle phase was determined according to hormonal level and identification of an LH surge in urine. Pain threshold was evaluated with a dynamometer applied to the forearm skin of the nondominant limb and abdominal wall. RESULT(S): Progestin-only contraceptive users showed a higher pain pressure threshold in the forearm (2.94 ± 0.96 vs. 2.74 ± 0.89 vs. 2.62 ± 0.92) and right (2.11 ± 0.87 vs. 1.83 ± 0.81 vs. 1.78 ± 0.77) and left abdomen (2.12 ± 0.88 vs. 1.79 ± 0.76 vs. 1.73 ± 0.70) than did combined hormonal contraceptive users and nonusers of hormonal contraceptives, respectively. Users of contraceptives that continuously release etonogestrel (subcutaneous implant, vaginal ring) or levonorgestrel (intrauterine devices) had higher pain thresholds. CONCLUSION(S): Women who used hormonal contraceptives enabling continuous release of etonogestrel or levonorgestrel tended to have higher pain thresholds than did nonusers of hormonal contraceptives.
Assuntos
Anticoncepcionais Femininos/administração & dosagem , Ciclo Menstrual/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Progestinas/administração & dosagem , Adulto , Estudos de Casos e Controles , Anticoncepcionais Femininos/efeitos adversos , Anticoncepcionais Orais Combinados/administração & dosagem , Anticoncepcionais Orais Hormonais/administração & dosagem , Estudos Transversais , Desogestrel/administração & dosagem , Implantes de Medicamento , Estradiol/sangue , Feminino , Humanos , Dispositivos Intrauterinos Medicados , Levanogestrel/administração & dosagem , Hormônio Luteinizante/sangue , Medroxiprogesterona/administração & dosagem , Medição da Dor , Pressão , Progesterona/sangue , Progestinas/sangue , Psicometria , Inquéritos e Questionários , Testosterona/sangue , Adulto JovemRESUMO
OBJECTIVE: We sought to evaluate in women with twin gestation the relationship between 17-hydroxyprogesterone caproate (17-OHPC) concentration and gestational age at delivery and select biomarkers of potential pathways of drug action. STUDY DESIGN: Blood was obtained between 24-28 weeks (epoch 1) and 32-35 weeks (epoch 2) in 217 women with twin gestation receiving 17-OHPC or placebo. Gestational age at delivery and concentrations of 17-OHPC, 17-hydroxyprogesterone, progesterone, C-reactive protein (CRP), and corticotrophin-releasing hormone were assessed. RESULTS: Women with higher concentrations of 17-OHPC delivered at earlier gestational ages than women with lower concentrations (P < .001). Women receiving 17-OHPC demonstrated significantly higher (P = .005) concentrations of CRP in epoch 1 than women receiving placebo but CRP values were similar in epoch 2 in both groups. A highly significant (P < .0001) positive relationship was observed between 17-OHPC concentration and progesterone and 17-hydroxyprogesterone concentrations at both epochs. Corticotropin-releasing hormone concentrations did not differ by treatment group. CONCLUSION: 17-OHPC may adversely impact gestational age at delivery in women with twin gestation.
Assuntos
Idade Gestacional , Hidroxiprogesteronas/efeitos adversos , Gravidez de Gêmeos/efeitos dos fármacos , Nascimento Prematuro/tratamento farmacológico , Progestinas/efeitos adversos , Caproato de 17 alfa-Hidroxiprogesterona , 17-alfa-Hidroxiprogesterona/sangue , Adulto , Biomarcadores/sangue , Proteína C-Reativa/análise , Hormônio Liberador da Corticotropina/sangue , Feminino , Humanos , Hidroxiprogesteronas/administração & dosagem , Hidroxiprogesteronas/sangue , Gravidez , Nascimento Prematuro/prevenção & controle , Progesterona/sangue , Progestinas/administração & dosagem , Progestinas/sangue , Resultado do TratamentoRESUMO
Since it is recognized that acute inflammation of the temporomandibular joint results in sleep disturbances in male rats, and that the orofacial region may display a site-specific effect of ovarian hormones on nociception, we hypothesized that distinct genders would respond differently when subjected to this inflammatory acute orofacial pain. Sleep was monitored after injection of saline/Freund's adjuvant into the temporomandibular joint in male and female (proestrus and diestrus phases) rats. Progesterone and stress-related hormones were also assessed. In males, Freund's adjuvant induced a significant nociceptive response and sleep disturbances. Behavior and sleep architecture in the females remained unaffected. Our results suggest that females and males present distinct responses to an acute model of orofacial pain.
Assuntos
Artrite/complicações , Modelos Animais de Doenças , Transtornos do Sono-Vigília/etiologia , Sono/fisiologia , Transtornos da Articulação Temporomandibular/complicações , Adjuvantes Imunológicos , Hormônio Adrenocorticotrópico/sangue , Hormônio Adrenocorticotrópico/fisiologia , Animais , Nível de Alerta/fisiologia , Artrite/fisiopatologia , Diestro/fisiologia , Ingestão de Líquidos/fisiologia , Ingestão de Alimentos/fisiologia , Eletroencefalografia , Eletromiografia , Feminino , Adjuvante de Freund , Masculino , Dor/fisiopatologia , Proestro/fisiologia , Progesterona/sangue , Progesterona/fisiologia , Progestinas/sangue , Progestinas/fisiologia , Distribuição Aleatória , Ratos , Ratos Wistar , Fatores Sexuais , Fases do Sono/fisiologia , Cloreto de Sódio , Transtornos da Articulação Temporomandibular/fisiopatologia , Vigília/fisiologiaRESUMO
The introduction of highly sensitive methods, such as transvaginal sonography and measurement of serum b-human chorionic gonadotropin, has dramatically improved ectopic pregnancy diagnosis in recent years. Early diagnosis is the key to successful and conservative management of women with ectopic pregnancy; however, approximately 50 percent of such women are initially misdiagnosed, resulting in significant morbidity and mortality. In order to improve diagnosis, several serum markers are being investigated including progesterone, CA 125, pregnancy-associated plasma protein-A, vascular endothelial growth factor, and maternal creatine kinase. Measurement of serum vascular endothelial growth factor, alone or together with other markers, could be a promising method for earlier and more accurate differential diagnosis. However, the clinical applicability of these findings remains to be evaluated in larger prospective studies.
Assuntos
Antígeno Ca-125/sangue , Creatina Quinase/sangue , Gravidez Ectópica/diagnóstico , Gravidez Tubária/diagnóstico , Proteína Plasmática A Associada à Gravidez/análise , Fator A de Crescimento do Endotélio Vascular/sangue , Biomarcadores/sangue , Feminino , Idade Gestacional , Humanos , Gravidez , Primeiro Trimestre da Gravidez/sangue , Gravidez Ectópica/sangue , Gravidez Tubária/sangue , Progesterona/sangue , Progestinas/sangueRESUMO
OBJECTIVE: To evaluate the effect of the addition of methyltestosterone to estrogen and progestogen therapy on postmenopausal sexual energy and orgasm. METHODS: Sixty postmenopausal women in a stable relationship with a partner capable of intercourse, and presenting sexual complaints that appeared after menopause, were randomly divided into two groups: EP (n = 29) received one tablet of equine estrogens (CEE) 0.625 mg plus medroxyprogesterone acetate (MPA) 2.5 mg and one capsule of placebo; EP + A (n = 31) received one tablet of CEE 0.625 mg plus MPA 2.5 mg and one capsule of methyltestosterone 2.0 mg; The treatment period was 12 months. The effects of treatment on sexual energy were assessed using the Sexual Energy Change Scale. The ability to reach orgasm in sexual relations with the partner was verified through monthly calendars and by calculating the ratio between monthly frequency of orgasms in sexual relations and monthly sexual frequency. RESULTS: There was a significant relationship between improvement in level of sexual energy and the addition of methyltestosterone to CEE/MPA treatment (p = 0.021). No significant effect on orgasmic capacity was noted after the treatment period. CONCLUSION: Addition of methyltestosterone to CEE/MPA therapy may increase sexual energy, but might not affect the ability to obtain orgasm in sexual relations.
Assuntos
Terapia de Reposição de Estrogênios , Estrogênios/farmacologia , Libido/efeitos dos fármacos , Metiltestosterona/farmacologia , Orgasmo/efeitos dos fármacos , Progestinas/farmacologia , Adulto , Estudos de Coortes , Método Duplo-Cego , Moduladores de Receptor Estrogênico/metabolismo , Terapia de Reposição de Estrogênios/efeitos adversos , Terapia de Reposição de Estrogênios/métodos , Estrogênios/sangue , Estrogênios Conjugados (USP) , Feminino , Humanos , Libido/fisiologia , Pessoa de Meia-Idade , Orgasmo/fisiologia , Pós-Menopausa , Progestinas/sangueRESUMO
Blood samples were collected during the estrous cycle (n=3), throughout gestation (n=3), and during the periparturient period (n=11) to assess serum concentrations of cortisol in pregnant and non-pregnant Asian elephants whose reproductive status was being monitored by serum progestin determination. While serum cortisol concentrations remained constant throughout gestation, progestin concentrations decreased significantly (p<0.05) in the second half of pregnancy, declining to undetectable levels by 3 days before calving. During the non-luteal phase of the estrous cycle serum progestins varied from undetectable levels to 100pg/ml (53+/-10.7pg/ml) then increased steadily during the luteal phase (322+/-207.5pg/ml). There were no significant differences between serum cortisol concentrations during the luteal and those of the non-luteal phase (p>0.05). The mean cortisol concentration during the estrous cycle was about twice that during pregnancy (p>0.05). No substantial changes in maternal cortisol were found during the course of pregnancy or the periparturient period.
Assuntos
Elefantes/sangue , Hidrocortisona/sangue , Prenhez/sangue , Progestinas/sangue , Animais , Ásia , Estro , Feminino , Gravidez , Valores de ReferênciaRESUMO
The introduction of highly sensitive methods, such as transvaginal sonography and measurement of serum b-human chorionic gonadotropin, has dramatically improved ectopic pregnancy diagnosis in recent years. Early diagnosis is the key to successful and conservative management of women with ectopic pregnancy; however, approximately 50 percent of such women are initially misdiagnosed, resulting in significant morbidity and mortality. In order to improve diagnosis, several serum markers are being investigated including progesterone, CA 125, pregnancy-associated plasma protein-A, vascular endothelial growth factor, and maternal creatine kinase. Measurement of serum vascular endothelial growth factor, alone or together with other markers, could be a promising method for earlier and more accurate differential diagnosis. However, the clinical applicability of these findings remains to be evaluated in larger prospective studies.
Assuntos
Feminino , Humanos , Gravidez , /sangue , Creatina Quinase/sangue , Gravidez Ectópica/diagnóstico , Gravidez Tubária/diagnóstico , Proteína Plasmática A Associada à Gravidez/análise , Fator A de Crescimento do Endotélio Vascular/sangue , Biomarcadores/sangue , Idade Gestacional , Primeiro Trimestre da Gravidez/sangue , Gravidez Ectópica/sangue , Gravidez Tubária/sangue , Progesterona/sangue , Progestinas/sangueRESUMO
BACKGROUND: Paradoxical sleep deprivation (PSD) associated with cocaine has been shown to enhance genital reflexes (penile erection-PE and ejaculation-EJ) in Wistar rats. Since hypertension predisposes males to erectile dysfunction, the aim of the present study was to investigate the effects of PSD on genital reflexes in the spontaneously hypertensive rat (SHR) compared to the Wistar strain. We also extended our study to examine how PSD affect steroid hormone concentrations involved in genital events in both experimental models. METHODS: The first experiment investigated the effects of PSD on genital reflexes of Wistar and SHR rats challenged by saline and cocaine (n = 10/group). To further examine the impact of the PSD on concentrations of sexual hormones, we performed a hormonal analysis of testosterone and progesterone in the Wistar and in SHR strains. Since after PSD progesterone concentrations decreased in the SHR compared to the Wistar PSD group we extended our study by investigating whether progesterone (25 mg/kg or 50 mg/kg) or testosterone (0.5 mg/kg or 1.0 mg/kg) administration during PSD would have a facilitator effect on the occurrence of genital reflexes in this hypertensive strain. RESULTS: A 4-day period of PSD induced PE in 50% of the Wistar rats against 10% for the SHR. These genital reflexes was potentiated by cocaine in Wistar rats whereas this scenario did not promote significant enhancement in PE and EJ in hypertensive rats, and the percentage of SHR displaying genital reflexes still figured significantly lower than that of the Wistar strain. As for hormone concentrations, both sleep-deprived Wistar and SHR showed lower testosterone concentrations than their respective controls. Sleep deprivation promoted an increase in concentrations of progesterone in Wistar rats, whereas no significant alterations were found after PSD in the SHR strain, which did not present enhancement in erectile responses. In order to explore the role of progesterone in the occurrence of genital reflexes, SHR were treated daily during the sleep deprivation period with progesterone; after the administration of this hormone and challenge with cocaine, we observed a significant increase in erectile events compared with the vehicle PSD SHR+cocaine group. CONCLUSION: Our data showed that the low frequency of genital reflexes found in SHR sleep deprived rats may be attributed to the lower concentrations of progesterone in these rats, based on the observation that progesterone replacement increased genital reflexes in this strain.
Assuntos
Disfunção Erétil/tratamento farmacológico , Hipertensão/complicações , Progesterona/farmacologia , Progestinas/farmacologia , Privação do Sono , Androgênios/sangue , Androgênios/farmacologia , Animais , Cocaína , Disfunção Erétil/induzido quimicamente , Masculino , Progesterona/sangue , Progestinas/sangue , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Comportamento Sexual Animal/efeitos dos fármacos , Testosterona/sangue , Testosterona/farmacologia , VasoconstritoresRESUMO
The Wobbler mouse, a mutant characterized by motoneuron degeneration in the cervical spinal cord, has been used to test the efficacy of novel treatments for human motoneuron diseases (HMD). Previous reports have shown that slow axonal transport is impaired in Wobblers and other models of HMD. Since progesterone (PROG) corrects some morphological, molecular, and functional abnormalities of Wobbler mice, we studied if steroid exposure for 8 weeks restored retrograde axonal transport by measuring motoneuron labeling after injection of fluorogold into the limb muscles. The dye was injected into forelimb biceps bracchii and flexor or into the rearlimb gastrocnemius muscles; 6 days later, the number of fluorescent motoneurons and the total number of cresyl violet stained motoneurons were counted in the cervical (C5-T1) or lumbar (L3-L5) spinal cord regions. A pronounced reduction (- 42.2%) of the percent of fluorescent motoneurons in Wobbler mice cervical cord was noted, which was significantly corrected after PROG treatment. In contrast, labeling of lumbar motoneurons was not reduced in Wobbler mice and was not affected by PROG treatment. In no case PROG showed an effect in control mice. Concomitantly, PROG slightly but significantly increased biceps weight of Wobbler mice. Behaviorally, PROG-treated Wobblers performed better on a motor test (hanging time from a horizontal rope) compared to untreated counterparts. We postulate a dual role for PROG in the Wobbler mouse, in part by prevention of motoneuron degeneration and also by enhancement of axonal transport. The latter mechanism could improve the traffic of neurotrophic factors from the forelimb muscles into the ailing motoneurons, improving neuromuscular function in this murine model of HMD.
Assuntos
Transporte Axonal/efeitos dos fármacos , Doença dos Neurônios Motores/tratamento farmacológico , Doença dos Neurônios Motores/fisiopatologia , Neurônios Motores/efeitos dos fármacos , Progestinas/uso terapêutico , Medula Espinal/patologia , Animais , Comportamento Animal , Vértebras Cervicais/patologia , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Progestinas/sangue , Estilbamidinas/metabolismo , Extremidade Superior/fisiopatologiaRESUMO
Several progestin-only long acting contraceptives are currently available in the form of implants or injectables. Vaginal rings are another contraceptive option in the final stages of development. These steroid-containing polymer rings are placed in the vagina, providing relatively constant drug release, thus allowing for lower effective doses. Vaginal rings have the advantage of being user-controlled and non-provider dependent, and their use is non-coital related. The first clinical study with medroxyprogesterone acetate vaginal rings was published in 1970. Since then numerous clinical trials testing different steroids and doses have followed. A large Phase III multicenter clinical trial with a levonorgestrel ring, releasing 20 microg/day, was coordinated and sponsored by WHO. The cumulative one-year pregnancy rate was 4. 5%. The principal reasons for discontinuation were menstrual disturbances (17.2%), followed by frequent expulsion of the ring (7. 1%), and vaginal symptoms (6.0%). The finding of erythematous lesions in the vagina in some women has led to the development of a more flexible device. Collaboration with industry should facilitate the manufacture of a redesigned levonorgestrel ring with a higher release rate. The Population Council is also developing a vaginal ring containing Nestorone for 6 months of continuous use. Ovulation inhibition was achieved in over 97% of the segments studied, with rings releasing either 50, 75, or 100 microg/day. No pregnancies occurred in women using the low-dose ring, while one pregnancy each occurred in the intermediate- and high-dose ring groups for a 6-month cumulative pregnancy rate of 0.0, 1.9, and 2.1%. Bleeding irregularities were common. Nestorone is orally inactive; therefore this ring is also excellent for use in lactating women.
Assuntos
Anticoncepcionais Femininos/administração & dosagem , Progestinas/administração & dosagem , Administração Intravaginal , Anticoncepcionais Femininos/sangue , Anticoncepcionais Femininos/normas , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/normas , Implantes de Medicamento/farmacocinética , Implantes de Medicamento/normas , Feminino , Humanos , Gravidez , Progestinas/sangue , Progestinas/normasRESUMO
This paper describes experiments designed to test the effect of depot medroxyprogesterone acetate (DMPA) on calcium metabolism of adult ovariectomized rats. The 24 animals were randomly assigned to control or treated groups. Treated rats received 15 mg of DMPA i.m. per week, during four or twelve weeks. Controls received solvent alone. The variables characterizing the metabolism of Ca (daily rates of intestinal absorption and excretion, bone accretion and resorption and the sizes of the exchangeable pools and their rate constants) were measured with the aid of 45Ca according to Aubert and Milhaud. No effects were observed at four weeks of treatment. After twelve weeks, treatment produced serum levels of 46.5 ñ 5.6 nmoles of medroxyprogesterone/L, reduction of bone turnover (Ca accretion and resorption rates) and of the size of the slow exchanging Ca compartment. The increase in true Ca intestinal absorption was compensated by the increased endogenous fecal Ca excretion. The mass of body Ca was not affected by treatment.
Assuntos
Animais , Feminino , Ratos , Cálcio/metabolismo , Acetato de Medroxiprogesterona/farmacologia , Ovariectomia , Progestinas/farmacologia , Reabsorção Óssea , Cálcio/análise , Fezes/química , Absorção Intestinal/efeitos dos fármacos , Acetato de Medroxiprogesterona/sangue , Progestinas/sangue , Distribuição AleatóriaRESUMO
This paper describes experiments designed to test the effect of depot medroxyprogesterone acetate (DMPA) on calcium metabolism of adult ovariectomized rats. The 24 animals were randomly assigned to control or treated groups. Treated rats received 15 mg of DMPA i.m. per week, during four or twelve weeks. Controls received solvent alone. The variables characterizing the metabolism of Ca (daily rates of intestinal absorption and excretion, bone accretion and resorption and the sizes of the exchangeable pools and their rate constants) were measured with the aid of 45Ca according to Aubert and Milhaud. No effects were observed at four weeks of treatment. After twelve weeks, treatment produced serum levels of 46.5 ñ 5.6 nmoles of medroxyprogesterone/L, reduction of bone turnover (Ca accretion and resorption rates) and of the size of the slow exchanging Ca compartment. The increase in true Ca intestinal absorption was compensated by the increased endogenous fecal Ca excretion. The mass of body Ca was not affected by treatment. (AU)