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Effective management and conservation of threatened species biodiversity requires knowledge of reproductive biology, such as cyclicity, mode, and age at maturity. We combined reproductive endocrinology and in-situ ultrasonography to examine reproductive characteristics of female Caribbean reef sharks Carcharhinus perezi, a widely distributed, threatened marine predator which remains largely understudied throughout its range. Unique to this study was the opportunity to conduct longitudinal assessments of two individuals, recaptured across multiple seasons during sampling in The Bahamas. Within- individual, paired hormone analyses and in-situ ultrasounds of female sharks that were confirmed as either pregnant, non-pregnant, or reproductively active, suggest a biennial reproductive cycle for Carcharhinus perezi. This unique opportunity to assess the reproductive biology of the same individuals over time underscore the importance of repeated sampling for elucidating population reproductive cyclicity of highly mobile sharks in the wild. [ABSTRACT FROM AUTHOR]

Effective management and conservation of threatened species biodiversity requires knowledge of reproductive biology, such as cyclicity, mode, and age at maturity. We combined reproductive endocrinology and in-situ ultrasonography to examine reproductive characteristics of female Caribbean reef sharks Carcharhinus perezi, a widely distributed, threatened marine predator which remains largely understudied throughout its range. Unique to this study was the opportunity to conduct longitudinal assessments of two individuals, recaptured across multiple seasons during sampling in The Bahamas. Within-individual, paired hormone analyses and in-situ ultrasounds of female sharks that were confirmed as either pregnant, non-pregnant, or reproductively active, suggest a biennial reproductive cycle for Carcharhinus perezi. This unique opportunity to assess the reproductive biology of the same individuals over time underscore the importance of repeated sampling for elucidating population reproductive cyclicity of highly mobile sharks in the wild.

Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) are two typical non-volatile disinfection by-products (DBPs) found in drinking water. Increasing evidence has demonstrated that they show reproductive toxicity. However, whether they might have endocrine disrupting properties remains largely unknown. To discover this, we treated male mice or pregnant mice with 0, 1-, 102-, 103-, 104-, or 5 × 104-fold maximal concentration level (MCL) of DCAA or TCAA in drinking water. In male mice, the levels of testosterone in serum and androgen receptor (AR) in testis were declined with ≥ 103-fold MCL of DCAA (26.4 mg/kg/d) or TCAA (52.7 mg/kg/d). In pregnant mice, miscarriage rates were increased with ≥ 104-fold MCL of DCAA (264 mg/kg/d) or ≥ 103-fold MCL of TCAA. The levels of FSH in serum were increased and those of estradiol and progesterone were reduced with ≥ 103-fold MCL of DCAA or TCAA. The protein levels of estrogen receptors (ERα and ERβ) in ovary were reduced with ≥ 102-fold MCL of DCAA (2.64 mg/kg/d) or TCAA (5.27 mg/kg/d). Exposure to some certain fold MCL of DCAA or TCAA also altered the protein levels of ERα and ERβ in uterus and placenta. Exposure to 5 × 104-fold MCL of both DCAA and TCAA showed the combined effects. Therefore, both DCAA and TCAA could be considered as novel reproductive endocrine disrupting chemicals, which might be helpful for further assessment of the toxicological effects of DCAA and TCAA and the awareness of reproductive endocrine disrupting properties caused by DCAA and TCAA in drinking water. [Display omitted] • DCAA and TCAA function as endocrine-disrupting chemicals. • DCAA and TCAA reduce the levels of testosterone in serum and androgen receptor (AR) in testis of male mice. • DCAA and TCAA induce pregnant mouse miscarriage. • DCAA and TCAA increase follicle stimulating hormone levels and reduce estradiol and progesterone levels in serum of pregnant mice. • DCAA and TCAA reduce the levels of estrogen receptors (ERα and ERβ) in ovaries, uterus, and placenta of pregnant mice. [ABSTRACT FROM AUTHOR]

Abstract: Reproductive endocrinology information is limited for Chinchilla lanigera, a South American species characterized by extremely long gestation and estrus cycle compared with others rodents. This study was designed to validate a non-invasive technique for monitoring ovarian endocrine activity. Animals were exposed indoors to natural photoperiod (31°S–64°W, Argentina); temperature range: 17–26°C, with food and water ad libitum. Radiolabelled infusion (n =4): 3H-estradiol (3H-E2) and 14C-progesterone (14C-P4) were injected (i.p). Biochemical validation: HPLC-UV detector was employed to determine natural steroids in urine and fecal extracts and to determine immunoreactive metabolites. Physiological validation: (1) pregnancy (n =5): body weight and urinary and fecal steroidal metabolites were measured until birth; (2) Seasonality (n =9): urine and feces were collected in May, August, November, and February. Total 3H-E2 and 14C-P4 radioactivity recovered was 60.5±15.5 and 74.5±19.4%, respectively. After 3H-E2 injection, urinary radioactivity peaked at 7.0±0.6hr; in contrast, urinary 14C-P4 excretion peaked at 44.0±4.0hr (p =0.000). Peak radioactivity in feces occurred between 24–48hr for both hormones. Several correlations were detected during pregnancy between body weight vs. urinary progestagens/day (r =0.44, p <0.03); vs. urinary progestagens/creatinine (r =0.73, p =2.9×10−5); vs. urinary estrogens/day (r =0.74; p <0.2); and vs. urinary estrogens/creatinine (r =0.74; p <2.0×10−5). On the other hand, urinary and fecal progestagen excretion exhibited significant seasonal fluctuations and urinary estrogen concentrations showed a similar pattern (p =0.062 for winter–spring vs. summer–autumn). This methodology proved to be useful for monitoring ovary endocrine activity in urine of chinchilla female. [Copyright &y& Elsevier]

The effect of estradiol and progesterone therapy in serum and liver on the lipid profile of naturally menopausal albino rats of the Wistar strain of different age groups (12,18 and 24months) have been measured and compared with the age matched groups. Three months old rats were used as young controls. The aged rats were administered subcutaneous injection of 17-ß-estradiol (0.1 µg/g body weight), progesterone (2.5 µg/g body weight) and similar concentrations of both in combined treatment for 1month and the level of triglycerides (TG), total lipids (TL), total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL) and very low density lipoprotein (VLDL) were measured in serum and liver of 3, 12, 18 and 24months old control as well as treated groups. The results show that TG, HDL, VLDL levels were increased significantly by 71%, 155%, 54%, respectively in liver of 24months old rats by combination treatment when compared with age matched control animals. The levels of TL, TC and LDL were decreased by 20%, 31%, and 30%, respectively in serum of 12 months old rats in combination treatment group. The effect was more significant in 12 and 24 months old female rats with administration of estrogen and combined (EP) treatments. The results indirectly suggest that hormone replacement therapy (HRT) can reduce the risk of cardiovascular disease (CVD) thereby playing a cardio-protective role by restoring lipid and hormone levels to the similar levels as found in young female animals. [ABSTRACT FROM AUTHOR]

The influence of estradiol and progesterone, alone or in combination, on the discrete phases of matrix-induced endochondral bone formation was investigated. Administration of estradiol and progesterone in combination increased mesenchymal cell proliferation, as indicated by [H] thymidine incorporaton into acid precipitable material. However, ornithine decarboxylase (ODC) activity was significantly suppressed by the combination of estradiol and progesterone. Also, this treatment did not influence theSO incorporation into proteoglycans on day 7. Mineralization of newly induced bone was quantitated by alkaline phosphatase,Ca incorporation into bone mineral and calcium content, and was found to be significantly increased by progesterone alone and in combination with estradiol in both matrix-induced plaques and tibial metaphysis. These results demonstrated the stimulatory role of progesterone in combination with estradiol in bone formation and mineralization. [ABSTRACT FROM AUTHOR]

Menstrual endometrial breakdown induced by estradiol and progesterone withdrawal is regularly attributed to vasospasm of spiral arteries causing ischemia and hypoxia. We investigated whether hypoxia actually occurred in an in vivo model of menstruation. Three complementary approaches were used to look for signs of hypoxia in fragments of human functionalis xenografted to ovariectomized immunodeficient mice bearing pellets-releasing estradiol and progesterone, and then deprived of ovarian steroids. Hormone withdrawal 21 d after grafting induced menstrual breakdown and MMP expression within 4 d. Local partial oxygen pressure (pO2) was measured by electron paramagnetic resonance using implanted lithium phtalocyanine crystals. In mice with hormone maintenance until sacrifice, pO2 was low one week after grafting (14.8±3.4 mmHg) but increased twofold from the second week when tissue was largely revascularized. After 3 wk, pO2 was not modified by hormone withdrawal but was slightly increased on hormone reimpregnation 4 d after removal (34.7±6.1 mmHg) by comparison with hormone maintenance (27.1±8.6 mmHg). These results were confirmed using fluorescence quenching-based OxyLite measurements. In a further search for signs of hypoxia, we did not find significant HIF1-α immunostaining, nor pimonidazole adducts after hormone withdrawal. We conclude that hypoxia is not needed to trigger menstrual-like tissue breakdown or repair in human endometrial xenograft.