Cytochrome P450 aromatase (CYP19) is a key enzyme in vertebrate steroidogenesis, catalyzing the conversion of C19 androgens to C18 estrogens such as beta-estradiol (E2). The objective of this study was to assess effects of the CYP19 inhibitor fadrozole on fathead minnow (Pimephales promelas) reproductive endocrinology and physiology in a short-term reproduction assay proposed for identifying sp...

Testicular function is regulated by pituitary hormones and also by paracrine and autocrine factors. A number of reports have pointed out the importance of estrogens and progesterone in male reproductive tract. Recently, we have reported in testicular biopsies from men with Sertoli Cell Only Syndrome (SCO) or Hypospermatogenesis (H) with Leydig cell hyperplasia (LCH) an increase in the expressio...

BACKGROUND Reports suggest a relationship between circulating sex hormone levels and breast cancer risk, but genetic association studies have been inconclusive. We investigated the association between levels of sex hormones and single nucleotide polymorphisms (SNPs) in genes coding for the enzymes that regulate them. METHODS We assayed circulating levels of estradiol, testosterone, estrone, a...

OBJECTIVE To demonstrate whether leptin modulates reproduction by a direct effect within the ovary. DESIGN Animal model. SETTING National Key Laboratory of Infertility. ANIMAL(S) Adult female db/db mice. INTERVENTION(S) Adult littermate wild-type (WT) and diabetic (db) leptin receptor (LR) mutant female mice were matched for the allograft of the ovary to construct new genotypic models, ...

Amphibian metamorphosis is an excellent example of hormone-dependent control of development. Thyroid hormones (THs) regulate almost all aspects of metamorphosis, including brain development and larval neuroendocrine function. Sex steroids are also important for early brain function, although little is known about interactions between the two hormonal systems. In the present study, we establishe...