During a follicular wave in mares, the two largest follicles (F1 and F2) begin to deviate in diameter when F1 is a mean of 22.5 mm. The intrafollicular effects of pregnancy-associated plasma protein-A (PAPP-A), IGF-I, activin-A and vascular endothelial growth factor (VEGF) on other follicular-fluid factors during deviation were studied. In four treated groups (n = 7/group), a single dose of one...

Metabolic clearance rates of testosterone (MCR(T)) and androstenedione (MCR(A)) were determined twice during the same cycle in six normal women, using a constant infusion of testosterone-(3)H and androstenedione-(14)C. Nonlabeled steroids served as internal standards. Plasma concentrations of testosterone (i(T)) and androstenedione (i(A)) were measured, and the blood production of testosterone ...

Oocytes matured in vitro are useful for assisted human and farm animal reproduction. However, the quality of oocytes is usually lower than that vivo oocytes, possibly due to absence some important signal regulators vitro. In this study, untargeted metabolomics was used detect changes metabolites follicular fluid (FF) during pig oocyte maturation culture medium maturation. Our results showed tot...

Endogenous steroid hormones and endocannabinoids (ECs) are important regulators in the stress response of human body. For measurement chronic stress, hair analysis has been established as method choice for long-term retrospective determination endogenous markers. A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantification five (cortisone, cortisol, androstenedione, test...

During late pregnancy in the ewe, ovarian function is suppressed by placental steroids and following parturition ovarian function is restored. This experiment determined the ovarian secretion of oestradiol and androstenedione during late pregnancy and the early postpartum period in ewes. Six ewes with ovarian autotransplants were transplanted with three day 6 embryos and three gave birth on day...

Microsomal estrogen synthetase (cytochrome P-450ES), also known as aromatase, was purified from fresh human placenta microsomes by DEAE-Trisacryl and testosterone-agarose chromatography. Estrogen synthetase assays were done with androstenedione as substrate, NADPH as electron donor, and a partially purified P-450 reductase from human placenta as the electron carrier. The specific cytochrome P-4...

Owl clutches typically hatch asynchronously, and brood size hierarchies develop. In this study, we describe intra-clutch variation of testosterone, androstenedione, estradiol, and corticosterone in Eastern screech owl egg yolks. In order to assess whether these hormones may have originated in the follicle, we also characterize variation of testosterone, androstenedione, and corticosterone withi...

Breast tumor homogenate from 17 patients was incu bated with androstenedione, and 13 tumors yielded es trone and/or estradici as metabolites. To ensure proper identification of the metabolites, we used a dual-labeling technique consisting of incubating tumor homogenate with [3H]androstenedione and adding 14C-estrogens after the reaction was stopped. The estrogen metabolites were isolated and pu...

The concentrations of androstenedione, testosterone, oestrone and oestradiol-17beta were measured in peripheral and ovarian venous blood and follicular fluid of women at various stages of the menstrual cycle. The concentration of oestradiol was similar in small follicles (diameter less than 8 mm) at all stages of the menstrual cycle and in large follicles (diameter greater than or equal to 8 mm...