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1.
J Endocrinol Invest ; 44(4): 851-863, 2021 Apr.
Article in English | MEDLINE | ID: mdl-32776198

ABSTRACT

CONTEXT: In preclinical studies, high androgen levels during pregnancy are associated with low birth weight and rapid postnatal weight gain in the offspring. However, human data linking prenatal androgens with birth weight and early life weight gain in the offspring are scarce. DESIGN: We evaluated 516 mother-child pairs enrolled in the New England birth cohorts of the Collaborative Perinatal Project (1959-1966). We assayed androgen bioactivity in maternal sera during third-trimester using a receptor-mediated luciferase expression bioassay. Age and sex-specific BMI Z-scores (BMIz), defined using established standards, were assessed at birth, 4 months, 1 year, 4 years, and 7 years. We used linear mixed models to evaluate the relation of maternal androgens with childhood BMIz overall and by sex. We examined the association of maternal androgens with fetal growth restriction. The association of weight trajectories with maternal androgens was examined using multinomial logistic regression. RESULTS: Higher maternal androgen levels associated with lower BMIz at birth (ß = - 0.39, 95% CI: - 0.73, - 0.06); this relation was sex-dependent, such that maternal androgens significantly associated with BMIz at birth in girls alone (ß = - 0.72, 95% CI: - 1.40, - 0.04). The relation of maternal androgens with fetal growth restriction revealed dose threshold effects that differed by sex. There was no significant association between maternal androgens and weight trajectory overall. However, we found a significant sex interaction (p = 0.01); higher maternal androgen levels associated with accelerated catch-up growth in boys (aOR = 2.14, 95% CI: 1.14, 4.03). CONCLUSION: Our findings provide evidence that maternal androgens may have differential effects on the programming of intrauterine growth and postnatal weight gain depending on fetal sex.


Subject(s)
Androgens/blood , Body-Weight Trajectory , Pregnancy Trimester, Third/blood , Prenatal Care , Adult , Androgens/analysis , Birth Weight , Body Mass Index , Child , Child Development/physiology , Child, Preschool , Cohort Studies , Correlation of Data , Female , Humans , Infant, Newborn , New England/epidemiology , Pregnancy , Prenatal Care/methods , Prenatal Care/statistics & numerical data , Sex Factors , Weight Gain/physiology
2.
Minerva Ginecol ; 65(6): 641-51, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24346252

ABSTRACT

Observations over the past decade using longitudinal data reveal a gender-specific shift in adrenal steroid production. This shift is represented by an increase in the circulating concentrations of delta 5 steroids in 85% of all women and is initiated only after the menopausal transition has begun. While the associated rise in the major adrenal androgen, dehydroepiandrosterone sulfate (DHEAS), is modest, the parallel rises in dehydroepiandrosteone (DHEA) and androstenediol (Adiol) are much more robust. These increases in circulating steroid concentrations are qualitatively similar on average between ethnicities but quantitatively different between individual women. Both circulating testosterone (T) and androstenedione (Adione) also rise concomitantly but modestly by comparison. This phenomenon presents a new and provocative aspect to the endocrine foundations of the menopausal transition and may provide important clues to understanding the fundamentals of mid-aged women's healthy aging, particularly an explanation for the wide diversity in phenotypes observed during the MT as well as their different responses to hormone replacement therapies. Experimental studies using the nonhuman primate animal model show an acute adrenal response to human chorionic gonadotropin (hCG) challenge as well as the presence of luteinizing hormone receptors (LHR) in their adrenal cortices. These experimental results support the concept that LHRs are recruited to the adrenal cortices of mid-aged women that subsequently function to respond to increasing circulating LH to shunt pregnenolone metabolites towards the delta 5 pathway. Future investigations are required to determine the relationship of these changes in adrenal function to symptoms and health outcomes of mid-aged women.


Subject(s)
Dehydroepiandrosterone , Menopause , Androgens , Animals , Dehydroepiandrosterone Sulfate , Humans , Testosterone
3.
Neuroscience ; 255: 219-25, 2013.
Article in English | MEDLINE | ID: mdl-24120552

ABSTRACT

Aged ovariectomized (OVX) female monkeys, a model for menopause in humans, show a decline in spine density in the dorsolateral prefrontal cortex (dlPFC) and diminished performance in cognitive tasks requiring this brain region. Previous studies in our laboratory have shown that long-term cyclic treatment with 17ß-estradiol (E) produces an increase in spine density and in the proportion of thinner spines in layer III pyramidal neurons in the dlPFC of both young and aged OVX rhesus monkeys. Here we used 3D reconstruction of Lucifer yellow-loaded neurons to investigate whether clinically relevant schedules of hormone therapy would produce similar changes in prefrontal cortical neuronal morphology as long-term cyclic E treatment in young female monkeys. We found that continuously delivered E, with or without a cyclic progesterone treatment, did not alter spine density or morphology in the dlPFC of young adult OVX rhesus monkeys. We also found that the increased density of thinner spines evident in the dlPFC 24h after E administration in the context of long-term cyclic E therapy is no longer detectable 20days after E treatment. When compared with the results of our previously published investigations, our results suggest that cyclic fluctuations in serum E levels may cause corresponding fluctuations in the density of thin spines in the dlPFC. By contrast, continuous administration of E does not support sustained increases in thin spine density. Physiological fluctuations in E concentration may be necessary to maintain the morphological sensitivity of the dlPFC to E.


Subject(s)
Dendritic Spines/drug effects , Estradiol/administration & dosage , Estrogens/administration & dosage , Prefrontal Cortex/drug effects , Animals , Cell Shape , Disease Models, Animal , Estradiol/blood , Estrogen Replacement Therapy , Estrogens/blood , Female , Macaca mulatta , Ovariectomy , Prefrontal Cortex/cytology
4.
Zoo Biol ; 30(5): 498-522, 2011.
Article in English | MEDLINE | ID: mdl-20938969

ABSTRACT

Cotton-top tamarins (Saguinus oedipus) are a critically endangered species that have been bred successfully in captivity for many years. For two decades, the Cotton-top Tamarin SSP(©) has been challenged with a high rate of reproduction combined with a history of contraceptive failures and nonrecommended births using the current Depo Provera(®) (medroxyprogesterone acetate) injection followed by MGA (melengestrol acetate) implant contraception combination. To address these issues we have developed and tested the use of levonorgestrel (LNG) as an effective contraception option for cotton-top tamarins. LNG was delivered in an injectable, gel matrix consisting of polylactic-co-glycolic acid, triethyl citrate and N-methylpyrrolidone. This gel matrix forms a biodegradable depot at the subcutaneous injection site providing slow release of the active ingredient. Gel matrix composition and LNG concentration were adjusted in four gel formulations to maximize the duration of contraceptive efficacy while minimizing immediate post-injection increases in fecal LNG concentration. LNG treatment (68.44 ± 8.61 mg/kg) successfully eliminated ovarian cycles (fecal pregnanediol-3-glucuronide (PdG) and estrone conjugates (E(1) C)) for 198.8 ± 70.3 days (formulation four; range 19-50 weeks). It was demonstrated that subcutaneous LNG depot injection was an effective, reversible contraceptive option for the management of cotton-top tamarins in captivity.


Subject(s)
Contraceptive Agents, Female/pharmacology , Levonorgestrel/pharmacology , Saguinus , Absorbable Implants , Animals , Animals, Zoo , Delayed-Action Preparations , Estrone/metabolism , Feces/chemistry , Female , Gels , Levonorgestrel/administration & dosage , Levonorgestrel/chemistry , Male , Menstrual Cycle/drug effects
5.
J Wildl Dis ; 46(1): 103-10, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20090023

ABSTRACT

Environmental contamination by petroleum hydrocarbons from anthropogenic sources can be a cause of stress for free-ranging wildlife. The response of wildlife to chemical contaminants requires that the hypothalamic-pituitary-adrenal (HPA) axis be precisely regulated to allow for proper glucocorticoid-mediated adaptive responses. Chronic oral exposure to low concentrations of bunker C fuel oil causes the development of adrenal hypertrophy in male ranch mink (Mustela vison) without increasing serum or fecal glucocorticoid concentrations. This hypertrophy is an adaptive response to fuel oil-induced adrenal insufficiency. To determine if the same phenomenon occurs in female mink or male mink exposed to artificially weathered fuel oil, female mink were fed 0 ppm (mineral oil) or 420 ppm fuel oil and male mink were exposed to 0 ppm, 420 ppm fuel oil, or 480 ppm artificially weathered fuel oil in the diet for 60-62 days. At the end of the exposure, serum glucocorticoid concentrations were assayed along with body and organ weight measurements. Fecal glucocorticoid concentrations were assayed at time points throughout the exposure. Male mink fed fuel oil or weathered fuel oil and female mink fed fuel oil had adrenal enlargement without any significant increases in the serum or fecal concentration of glucocorticoids, which is consistent with fuel oil-induced adrenal insufficiency. To address the physiological consequences of adrenal insufficiency, fuel oil-exposed male mink were administered an adrenocorticotropic hormone (ACTH) stimulation test. Fuel oil-exposed animals had a smaller incremental increase in serum glucocorticoid concentration after ACTH challenge compared to control animals. Our findings provide further evidence that the HPA axis of fuel oil-exposed animals is compromised and, therefore, not able to respond appropriately to the diverse stressors found in the environment.


Subject(s)
Adrenal Glands/drug effects , Adrenal Insufficiency/veterinary , Environmental Exposure , Fuel Oils/toxicity , Mink , Administration, Oral , Adrenal Glands/pathology , Adrenal Insufficiency/chemically induced , Adrenal Insufficiency/pathology , Adrenocorticotropic Hormone/metabolism , Animals , Body Weight/drug effects , Dose-Response Relationship, Drug , Feces/chemistry , Female , Glucocorticoids/analysis , Glucocorticoids/blood , Hypertrophy/chemically induced , Hypertrophy/veterinary , Male , Organ Size/drug effects , Random Allocation , Sex Factors , Toxicity Tests, Chronic/veterinary
6.
Arch Environ Contam Toxicol ; 54(2): 337-47, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17763884

ABSTRACT

Animals living in the near-shore marine environment are predisposed to contact with chemical contaminants through land- and ocean-based activities. The release of petroleum hydrocarbons into the marine environment is a stressor to this environment and its resident wildlife. The stress response to chemical threats is dependent on an intact hypothalamic-pituitary-adrenal axis, which also may be a target to the effects of these chemicals. Ranch mink (Mustela vison) were used as surrogates for sea otters (Enhydra lutris) to examine the development of adrenal hypertrophy after chronic, oral exposure to low concentrations of bunker C fuel oil. Animals were fed three different concentrations of fuel oil (48, 520, and 908 ppm) or mineral oil (control) for 60-62 days. At the end of the exposure, blood and fecal samples were collected and organs were weighed and examined microscopically. In all fuel oil groups, exposure resulted in adrenal hypertrophy, an adaptation suggestive of adrenal activation. However, concentrations of serum and fecal glucocorticoids and serum progesterone were not elevated over control values. Hematologic parameters and serum chemistries showed no changes consistent with increased adrenal activity. In addition, adrenal glands from animals fed the higher concentrations of fuel oil contained large numbers of heavily vacuolated cells. We conclude that petroleum hydrocarbons are inducing an adrenal insufficiency that leads to the adaptive enlargement of the gland. This would increase the susceptibility of fuel oil-exposed animals to the deleterious effects of other environmental stressors.


Subject(s)
Adrenal Glands/drug effects , Adrenal Insufficiency/chemically induced , Fuel Oils/toxicity , Mink , Administration, Oral , Adrenal Glands/pathology , Adrenal Insufficiency/metabolism , Adrenal Insufficiency/pathology , Adrenal Insufficiency/veterinary , Alanine Transaminase/blood , Animals , Brain/drug effects , Brain/pathology , Feces/chemistry , Glucocorticoids/blood , Hematologic Tests , Hydrocortisone/metabolism , Liver/drug effects , Liver/pathology , Male , Mink/blood , Mink/metabolism , Organ Size/drug effects , Progesterone/blood , Toxicity Tests, Chronic
7.
Reprod Fertil Dev ; 18(6): 667-76, 2006.
Article in English | MEDLINE | ID: mdl-16930513

ABSTRACT

Domestic ewes (Ovis aries) were immunised with porcine zonae pellucidae (pZP) or pZP conjugated to keyhole limpet haemocyanin (KLH) in adjuvant(s) to examine the feasibility of the species to serve as a model for further development of pZP-based vaccines in ungulates. Two immunisation groups were employed, with a third group receiving only adjuvant (n = 5 per group). Early in the study, oestrous activity was monitored by the use of a vasectomised ram fitted with a marking harness. Eventually, ewes were exposed to an intact ram for breeding. In addition, weekly serum and every-other-day faecal samples were collected to measure pZP antibodies and progesterone metabolite concentrations respectively. At the conclusion of the study, fecundity was established, and ovarian tissue was examined. Ewes immunised against pZP : KLH with adjuvant produced minimal antibody absorbance levels, displayed normal oestrous cycles, became pregnant upon introduction of the intact ram and exhibited normal ovarian histopathology. Ewes immunised against pZP with adjuvant produced high antibody absorbance levels, were acyclic following primary immunisation and were infertile. Examination of the ovarian tissue revealed atrophic changes that included: (1) the absence of growing follicles; (2) significant reduction in the number of primordial follicles; and (3) the presence of abnormal granulosa cell clusters lacking oocytes. Antisera displayed immunoreactivity to the major components of pZP, and immunohistochemical labelling of ovarian tissue showed specificity to the ZP. These data are the first generated in an ungulate species showing deleterious effects of pZP immunisation on folliculogenesis and oestrous cyclicity.


Subject(s)
Hormones/physiology , Immunization/veterinary , Ovarian Follicle/growth & development , Sheep/physiology , Swine/immunology , Zona Pellucida/immunology , Adjuvants, Immunologic , Animals , Antibodies/blood , Blotting, Western , Contraception, Immunologic/veterinary , Enzyme-Linked Immunosorbent Assay , Estrous Cycle , Female , Fertility , Hemocyanins/immunology , Immunohistochemistry
8.
Article in English | MEDLINE | ID: mdl-14991909

ABSTRACT

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to alter carbohydrate utilization and specific steps in lipid metabolism. TCDD interacts with estradiol in mobilizing specific fatty acids in chickens that may be a cause of cranial/beak malformations in this species. This study was designed to test the hypothesis that TCDD simultaneously alters critical fatty acid mobilization during early pregnancy and determine if those changes correlate to morphological defects of the developing neural tube in the nonhuman primate. Cynomolgus macaques were treated with a single dose of 4 microg/kg body weight (BW) TCDD on gestational day 15 or 20. Pregnancies were terminated by hysterectomy on gestational day 24-26 and embryos were examined to determine morphology of the developing neural tube. Maternal blood samples were used for fatty acid quantification. Embryos exhibited cellular changes, mainly increased cell death, and intercellular spaces in the neural tube, suggestive of an adverse effect on the developing nervous system. Significant decreases on fatty acid composition were found on some of the eight classes of lipids analyzed. Particularly, a decrease was observed in the n-3 (40-60%) and n-6 (47-75%) essential fatty acids in treated pregnancies compared to untreated controls. These data demonstrate the effect of TCDD in decreasing maternal levels of n-3 and n-6 fatty acids that are considered necessary for normal development in mammals. Since neural tube development is dependent, in part, on n-3 and n-6 fatty acids, it is possible that the limitation of these essential fatty acids in plasma resulted in the observed detrimental effects on early brain development.


Subject(s)
Fatty Acids/metabolism , Neural Tube Defects/chemically induced , Polychlorinated Dibenzodioxins/toxicity , Animals , Brain/pathology , Embryo, Mammalian/drug effects , Embryo, Mammalian/pathology , Fatty Acids/analysis , Female , Lipid Mobilization/drug effects , Lipids/blood , Lipids/chemistry , Macaca fascicularis , Neural Tube Defects/pathology , Polychlorinated Dibenzodioxins/pharmacology , Pregnancy
9.
Conf Proc IEEE Eng Med Biol Soc ; 2004: 1998-2001, 2004.
Article in English | MEDLINE | ID: mdl-17272109

ABSTRACT

Preliminary evidence of FSH suppression as a marker of postpartum ovarian recrudescence is presented. Falling FSH concentration in response to ovarian follicular estrogenic secretory activity apparently signals the reestablishment of menstrual cycles. We propose to investigate further this phenomenon with the development of a portable FSH biosensor. The FSH biosensor design is based on SPR and biological thin-film technologies and is incorporated as a key element of the fertility information appliance. It is possible that the device could be a useful natural family planning tool, especially during the return to fertility after childbirth.

10.
Am J Primatol ; 61(3): 111-21, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14610729

ABSTRACT

This study was designed to test the hypothesis that basal estrone conjugate (E1C) profiles do not accurately detect ovarian function when ovarian estrogen production is low or absent. We employed surgical removal of active ovaries from laboratory rhesus macaques to simulate an acute decline in ovarian estrogen production. In the first experiment, urine samples collected prior to and following ovariectomy (Ovx) were subjected to high-performance liquid chromatography (HPLC) separation. Eluates were then assayed for E1C immunoreactive components. The results indicated a modest decrease in total immunoreactive polar conjugates following ovariectomy, with no substantial change in the overall retention profile. In the second experiment, estradiol (E2) cypionate injections were used to replace the E2 component of ovarian estrogen production in the treated (Tx) group, while the control group (C) received only vehicle. Urine samples were hydrolyzed and individual estrogens were separated by celite chromatography prior to immuno-assay. Both the Tx and C groups exhibited similar urinary excretion levels of estrone (E1), E2, and E1C prior to Ovx (Pre-Ovx) and after Ovx (Post-Ovx), but there were significant differences between groups after treatment (Post-Tx). Significant differences were observed in the Tx group's excretion of E1, E2, and E1C in the Pre- vs. Post-Ovx samples and in the Post-Ovx and Post-Tx samples. The C group also showed the expected significant differences in the Pre- vs. Post-Ovx samples, as well as in the Pre-Ovx and Post-Tx samples. The results indicate that the use of E1C measurements is clearly a suitable method for monitoring ovarian function in intact, cycling animals, but urinary E2 measurements are required to verify loss of follicular activity.


Subject(s)
Estradiol/analogs & derivatives , Estrogens/biosynthesis , Estrone/urine , Macaca mulatta/metabolism , Animals , Chromatography, High Pressure Liquid , Estradiol/metabolism , Female , Ovariectomy , Radioimmunoassay
11.
Endocrinology ; 144(2): 467-73, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12538606

ABSTRACT

Estradiol (E2) production by human luteinized granulosa cells (hLGC) is inhibited by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The molecular target of TCDD toxicity has not been identified. The decrease in E2 is ameliorated by androgen substrate addition and is not associated with changes in aromatase cytochrome P450 (P450arom) activity or protein expression. An antihuman 17alpha-hydroxylase/17,20-lyase cytochrome P450 (P450c17) antisera and a direct radiometric assay of 17,20-lyase activity were used to test the hypothesis that TCDD targets P450c17, thereby decreasing substrate availability for E2 synthesis by hLGC. P450c17 expression and 17,20-lyase activity were detected in hLGC with high levels of E2 secretion. Western immunoblot analysis demonstrated that TCDD treatment of hLGC decreased the expression of P450c17 by as much 50% (P < 0.05). TCDD exposure induced a 65% decrease in 17,20-lyase activity (P < 0.05), but no changes were seen in P450arom or in nicotinamide adenine dinucleotide phosphate (reduced)-cytochrome P450 oxidoreductase (reductase). Furthermore, the decreases in P450c17 and 17,20-lyase were proportional to the inhibition of E2 secretion. We conclude that the molecular target for endocrine disruption of hLGC by TCDD is P450c17, specifically decreasing the supply of androgens for E2 synthesis, and that it does not involve either P450arom or the redox partner protein reductase.


Subject(s)
Estradiol/metabolism , Granulosa Cells/enzymology , Luteinization/drug effects , Polychlorinated Dibenzodioxins/pharmacology , Steroid 17-alpha-Hydroxylase/metabolism , Teratogens/pharmacology , Aromatase/metabolism , Cells, Cultured , Estradiol/biosynthesis , Female , Granulosa Cells/cytology , Granulosa Cells/metabolism , Humans , Microsomes/drug effects , Microsomes/enzymology , NADPH-Ferrihemoprotein Reductase/metabolism , Oxidation-Reduction , Pregnancy
12.
Reprod Toxicol ; 17(1): 87-93, 2003.
Article in English | MEDLINE | ID: mdl-12507663

ABSTRACT

This study tests the idea that the environmental toxicant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), affects human trophoblast differentiation and alters the secretion of chorionic gonadotropin (CG). Primary cultures of cytotrophoblast cells were incubated under differentiation-inducing and nondifferentiation-inducing conditions in the presence or absence of different concentrations of TCDD. Levels of immunoreactive CG as well as bioactive CG were measured in culture supernatants. TCDD caused a significant increase in the secretion of immunoreactive CG from differentiated trophoblast cultures but had no effect on the secretion of bioactive hormone. The net effect was a TCDD-dependent reduction in the CG bioactive/immunoreactive (B/I) ratio for differentiated trophoblast cultures. TCDD had no effect on immunoreactive or bioactive CG secretion by undifferentiated trophoblasts. Immunocytochemical studies showed that TCDD had no effect on the morphologic differentiation of trophoblast cells as determined by staining nuclei and desmosomal proteins. On the other hand, immunocytochemical staining for CG was increased in cells exposed to TCDD compared to control cells. These in vitro results support earlier in vivo studies in macaques suggesting that trophoblast is a target for TCCD and that TCDD-induced early pregnancy loss is accompanied by a decrease in the CG B/I ratio.


Subject(s)
Chorionic Gonadotropin/metabolism , Environmental Pollutants/toxicity , Polychlorinated Dibenzodioxins/toxicity , Teratogens/toxicity , Trophoblasts/drug effects , Cell Nucleus/drug effects , Cell Nucleus/pathology , Cells, Cultured , Culture Media, Conditioned/chemistry , Desmosomes/chemistry , Desmosomes/drug effects , Dose-Response Relationship, Drug , Humans , Immunohistochemistry , Proteins/analysis , Trophoblasts/metabolism , Trophoblasts/pathology
13.
Am J Physiol Endocrinol Metab ; 284(3): E521-30, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12441312

ABSTRACT

The Study of Women's Health Across the Nation (SWAN) is a multiethnic cohort study of middle-aged women enrolled at seven US sites. A subset of 848 women completed a substudy in which their urinary gonadotropins and sex steroid metabolites were assessed during one complete menstrual cycle or up to 50 consecutive days. Urine was analyzed for LH, FSH, estrone conjugates (E1c), and pregnanediol glucuronide (Pdg). To prepare for serial analysis of this large, longitudinal database in a population of reproductively aging women, we examined the performance of algorithms designed to identify features of the normal menstrual cycle in midreproductive life. Algorithms were based on existing methods and were compared with a "gold standard" of ratings of trained observers on a subset of 396 cycles from the first collection of Daily Hormone Substudy samples. In evaluating luteal status, overall agreement between and within raters was high. Only 17 of the 396 cycles evaluated were considered indeterminate. Of the 328 cycles rated as containing evidence of luteal activity (ELA), 320 were considered ELA by use of a Pdg threshold detection algorithm. Of 51 cycles that were rated as no evidence of luteal activity, only 2 were identified by this algorithm as ELA. Evaluation of the day of the luteal transition with methods that detected a change in the ratio of E1c to Pdg provided 85-92% agreement for day of the luteal transition within 3 days of the raters. Adding further conditions to the algorithm increased agreement only slightly, by 1-8%. We conclude that reliable, robust, and relatively simple objective methods of evaluation of the probability and timing of ovulation can be used with urinary hormonal assays in early perimenopausal women.


Subject(s)
Hormones/urine , Menstrual Cycle/urine , Ovulation Detection/methods , Algorithms , Corpus Luteum/physiology , Female , Humans , Middle Aged , Prospective Studies
14.
Biol Reprod ; 68(1): 244-51, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12493720

ABSTRACT

The in vitro effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on steroid metabolism in human luteinized granulosa cells (hLGC) have been summarized as a decreased estradiol (E(2)) production without altering either E(2) metabolism or cytochrome P450 aromatase activity. In the present study, hLGC were used to analyze the fate of different substrates for cytochrome P450 17alpha-hydroxylase/17,20-lyase (P450(c17)) in the presence or absence of TCDD. Human LGCs were plated directly on plastic culture dishes in medium supplemented with 2 IU/ml of hCG. TCDD (10 nM) or its solvent was added directly to the cells at the time of medium change, every 48 h for 8 days. The objective of the experiment was to test the hypothesis that exogenous steroid, substrate for P450(c17), would reduce the TCDD effects on E(2) synthesis. With dehydroepiandrosterone (DHEA) (a P450(c17) product), a dose-related increase in E(2) production was observed and the effect of TCDD on lowering E(2) production disappeared. In contrast, with increasing doses, up to 10 micro M, of pregnenolone (P(5)), no change in E(2) production was observed. However, 17alpha-hydroxypregnenolone (17P(5)) at 10 micro M produced a modest but significant increase in the E(2) production. Treatments with P(5) and 17P(5) did not alter the effect of TCDD on E(2) production. Radiolabeled substrate utilization by hLGC suggests that the principal metabolic pathway for Delta5 substrates is the conversion to a Delta4 product probably by a very active 3beta-hydroxysteroid dehydrogenase. We conclude that estrogen production by hLGC is limited at the level of lyase activity. Thus, these data suggest that the most likely target for the TCDD-induced inhibition of estrogen synthesis by hLGC is the 17,20-lyase activity of the P450(c17) enzyme complex.


Subject(s)
Dihydrotestosterone/analogs & derivatives , Estradiol/biosynthesis , Luteal Cells/drug effects , Luteal Cells/metabolism , Polychlorinated Dibenzodioxins/toxicity , Steroids/metabolism , 3-Hydroxysteroid Dehydrogenases/antagonists & inhibitors , Cells, Cultured , Dihydrotestosterone/pharmacology , Environmental Pollutants/toxicity , Enzyme Inhibitors/pharmacology , Female , Humans , In Vitro Techniques , Models, Biological , Steroid 17-alpha-Hydroxylase/antagonists & inhibitors , Steroid 17-alpha-Hydroxylase/metabolism , Substrate Specificity
15.
J Psychiatr Res ; 36(6): 423-8, 2002.
Article in English | MEDLINE | ID: mdl-12393312

ABSTRACT

The pharmacokinetics of dexamethasone have been found to be related to endogenous hypothalamic-pituitary-adrenal (HPA) axis activity. Lower plasma dexamethasone levels in psychiatric patients (especially depressed) who are dexamethasone suppression test (DST) nonsuppressors have previously been reported. Since DST nonsuppression is one measure of HPA axis hyperactivity and is usually associated with relatively increased plasma cortisol levels and lower post dose plasma dexamethasone levels, we hypothesized that hypercortisolemia can induce a more rapid disappearance of dexamethasone from plasma. We therefore studied the kinetics of dexamethasone in rabbits before and after a period of sustained hypercortisolemia produced by administration of IM hydrocortisone acetate, a slowly absorbed salt of cortisol. Mean dexamethasone half-life decreased significantly from baseline of 1.92 h on day zero in seven rabbits to 1.17 h on experimental day 17 of induced hypercortisolemia (P < 0.001), while there was no significant change in saline treated controls (n = 3). Dexamethasone half-life had returned to the baseline levels when retested 88 days later on experimental day 105. The results indicate that pronounced hypercortisolemia decreases dexamethasone half-life in rabbits, and support the concept that increased circulating cortisol levels induce hepatic enzymes that metabolize dexamethasone. Thus, the lower postdexamethasone plasma dexamethasone levels and decreased dexamethasone half-life in DST nonsuppressors may in part reflect the effect of prior or coincident hypercortisolemia.


Subject(s)
Anti-Inflammatory Agents/blood , Dexamethasone/blood , Hydrocortisone/blood , Hypothalamo-Hypophyseal System/metabolism , Pituitary-Adrenal System/metabolism , Animals , Male , Rabbits , Random Allocation
16.
Reprod Suppl ; 60: 169-76, 2002.
Article in English | MEDLINE | ID: mdl-12220156

ABSTRACT

The potential for the application of porcine zona pellucida (PZP) immunocontraception in wildlife population management has been tested over a 15 year period and promises to provide a useful wildlife management tool. These studies have provided evidence indicating that the use of PZP immunocontraception in wildlife: (i) is effective at both the physiological and population level (Liu et al., 1989; Kirkpatrick et al., 1996; Turner et al., this supplement); (ii) is deliverable by remote means (Kirkpatrick et al., 1990; Shideler, 2000); (iii) is safe in pregnant animals (Kirkpatrick and Turner, this supplement); (iv) is reversible (Kirkpatrick et al., 1991; Kirkpatrick and Turner, this supplement); (v) results in no long-term debilitating health problems (Kirkpatrick et al., 1995; Turner and Kirkpatrick, this supplement); (vi) has no implications for passage through the food chain (Harlow and Lane, 1988); and (vii) is reasonably inexpensive (J. F. Kirkpatrick, personal communication). This report presents the results of a 5 year study in tule elk (Cervus elaphus nannodes), 3 years of which were on the application of PZP immunocontraception to an expanding elk population living in a wilderness area of Point Reyes National Seashore in Marin County, CA, where hunting is not allowed and culling is not publicly acceptable.


Subject(s)
Animals, Wild , Antigens/administration & dosage , Contraception, Immunologic/veterinary , Deer , Egg Proteins/administration & dosage , Membrane Glycoproteins/administration & dosage , Receptors, Cell Surface , Vaccines, Contraceptive/administration & dosage , Animals , California , Estrogens/analysis , Feces/chemistry , Female , Population Control , Progesterone/analysis , Swine , Zona Pellucida Glycoproteins
17.
Am J Primatol ; 57(2): 79-90, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12111683

ABSTRACT

The first objective of the present study was to determine the metabolic form and rate of excretion of ovarian hormone metabolites in the urine and feces of female squirrel monkeys injected with radiolabeled progesterone (Po) and estradiol. The major portion of the urinary metabolites of both hormones was excreted within 16-24 hr post-injection. Estrogen and Po isotopes in feces exhibited an excretion peak at 16 hr post-injection. The majority of recovered radiolabel of both hormones was excreted in feces. Chromatographic separation of fecal extractions indicated that the major estrogen metabolites in feces are in the free as opposed to the conjugated form. The radioactivity and immunoreactivity for estrone and estradiol (E(1) and E(2), respectively) in eluates of fecal samples subjected to celite co-chromatography indicated that both free E(1) and E(2) exist as excretion products in the feces of female squirrel monkeys. The major radioactive peaks for Po metabolites showed peaks in the elution profile at or very near the Po standard, and corresponded with the celite co-chromatography elution profile of Po standard when subjected to enzyme immunoassay (EIA). The second objective was to validate the application of EIA systems to measure fecal metabolites. Reproductive events of one female squirrel monkey across one annual reproductive cycle are described using the endocrine profile generated from fecal steroid assays. Examination of this profile confirmed that longitudinal fecal sampling and steroid hormone metabolite measurement in feces was not only feasible and practical, but accurately detected known reproductive events as well.


Subject(s)
Estradiol/metabolism , Estradiol/urine , Feces/chemistry , Progesterone/metabolism , Progesterone/urine , Saimiri/metabolism , Animals , Carbon Radioisotopes , Chromatography , Chromatography, High Pressure Liquid , Female , Immunoenzyme Techniques , Pregnancy , Saimiri/urine
18.
Hum Reprod ; 17(4): 1060-6, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11925406

ABSTRACT

BACKGROUND: To examine the reliability of HCG as a biomarker for early pregnancy loss, five experienced researchers independently assessed data from 153 menstrual cycles, determining whether each cycle represented 'no conception,' a 'continuing conception' or a 'conception lost.' METHODS: Urine samples were analysed by immunoradiometric assay using a combination of capture antibodies for the intact heterodimer (B109) and for an epitope common to the beta subunit and the beta core fragment (B204). For each cycle, HCG data were presented as graphs of daily assay results. Summary statistics for HCG assays from 46 women who had undergone bilateral tubal ligation represented baseline values. RESULTS: Pairwise agreement among the assessors for any of the three options ranged from 78-89%. At least three experts agreed for 147 cycles (96%), accounting for 28 conception losses and 19 continuing conceptions. The multi-rater kappa was 0.62 for the conception lost category and 0.68 for continuing conceptions, indicating substantial agreement. CONCLUSION: The main sources of disagreement involved deciding whether there was sufficient information for assessment, interpreting cycle parameters such as cycle length or bleeding event, and interpreting a distinct HCG rise pattern that does not exceed the baseline value obtained from the sterilized women.


Subject(s)
Abortion, Spontaneous/diagnosis , Abortion, Spontaneous/urine , Chorionic Gonadotropin/urine , Adult , Biomarkers/urine , Female , Humans , Immunoradiometric Assay , Observer Variation , Pregnancy
19.
Biol Reprod ; 65(6): 1718-25, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11717133

ABSTRACT

The study presented characterizes the ovarian and pituitary function of the aged female macaque through a complete annual reproductive cycle to compare hormone dynamics during the human and nonhuman primate menopausal transition. Data collected over an entire year from aged macaque females indicated that urinary FSHbeta subunit baseline levels statistically significantly increased in females after age-related abnormal menstrual cycles occurred. These abnormal cycles were followed by anovulation and complete cessation of follicular activity. No statistically significant difference in urinary FSHbeta subunit levels was seen between females that exhibited year-round normal ovarian cycles and those that exhibited seasonal ovarian cycles followed by an interval of anovulation during the nonbreeding season. Basal urinary estrogen metabolite levels were not observed to decrease until ovarian cycles became abnormal and FSHbeta subunit levels began to rise. Early follicular phase circulating inhibin beta levels were statistically significantly reduced only when ovariectomized females were compared to the year-round normally cycling females. A statistically nonsignificant trend toward decreased inhibin secretion, however, was apparent in aged females with normal cycles, aged females with abnormal cycles, anovulatory aged females, and finally, ovariectomized females. Whereas decreased circulating levels of dehydroepiandrosterone sulfate showed a general decline over the 1-yr study period in all groups, they were lowest in the year-round normally cycling group, progressively higher in the normal-to-anovulatory group and abnormal-to-anovulatory group, and highest in the anovulatory group. Finally, the nonbreeding season was associated with the highest number of abnormal cycles, suggesting that onset of complete ovarian senescence in these study macaques was more likely to occur during that time (i.e., females were less likely to return to normal ovarian cycles the following breeding season and more likely to exhibit permanent ovarian quiescence).


Subject(s)
Aging , Estrogens/metabolism , Follicle Stimulating Hormone/urine , Progesterone/metabolism , Animals , Anovulation , Dehydroepiandrosterone Sulfate/blood , Estrone/urine , Female , Follicle Stimulating Hormone, beta Subunit , Inhibin-beta Subunits/blood , Macaca mulatta , Menopause , Ovariectomy , Ovary/physiology , Ovulation , Pituitary Gland/physiology , Seasons
20.
Contraception ; 63(6): 335-42, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11672557

ABSTRACT

Intravaginal administration of an anti-microbial agent, (Ala(8,13,18))-magainin II amide, during blastocyst implantation inhibits pregnancy establishment in a dose-related manner in the rhesus monkey (Macaca mulatta). In the present study, mated female rhesus monkeys were vaginally inserted with tampons containing vehicle (Group 1; n = 5) and test agent (magainin, 0.5 mg/animal; Group 2; n = 6) on cycle day 20. Endometrial tissue samples were collected on Cycle Day 24 from all monkeys and processed for morphometric and ultrastructural analysis. Concentrations of estradiol-17beta, progesterone, and chorionic gonadotrophin in peripheral circulation were determined, which revealed that two monkeys in Group 1 were pregnant while no animals were pregnant in Group 2. Endometrial morphology, however, revealed histologic evidence of pregnancy in three out of the six magainin-treated animals. It appears that intra-vaginal administration of magainin II amide had a marginal effect on the implantation stage endometrium and the initiation of the implantation process in the rhesus monkey.


Subject(s)
Anti-Infective Agents/adverse effects , Embryo Implantation/drug effects , Embryo Implantation/physiology , Endometrium/anatomy & histology , Endometrium/drug effects , Administration, Intravaginal , Angiogenesis Inhibitors/administration & dosage , Animals , Antimicrobial Cationic Peptides , Endometrium/blood supply , Endothelium, Vascular/ultrastructure , Epithelial Cells/ultrastructure , Female , Macaca mulatta , Male , Microscopy, Electron , Peptides/administration & dosage , Pregnancy
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