Recent studies have demonstrated that some hormones are present in baleen powder from bowhead (Balaena mysticetus) and North Atlantic right (Eubalaena glacialis) whales. To test the potential generalizability of this technique for studies of stress and reproduction in large whales, we sought to determine whether all major classes of steroid and thyroid hormones are detectable in baleen, and whe...

Hormonal induction of sexual receptivity in ovariectomized female mice can be effectively reinstated by sequential administration of estradiol and progesterone. In this regard, mice appear to be similar to other rodents. While it is generally accepted that hypothalamic progesterone receptors function as estradiol-induced transcription factors in the induction of sexual receptivity in rats, hams...

The grey mullet fingerling were imported to Iran in 1997 from Hong Kong and in coastal fish pond of north part of Iran were successfully cultured in order to obtain broodstocks and induce artificial reproduction. Seasonal changes in serum concentrations of Testosterone, 17-β Estradiole (E2), 17-α Hydroxy Progesterone and also the level of calcium, Triglyceride and cholesterol in females grey mu...

background: milk is a valuable sources of nutrition in the human diet however; there are reports on safety of milk steroid hormones contain. this study designed to determine the level of steroid hormones including estrone (e1), 17β-estradiol (e2), and estriol (e3) in raw and pasteurized milk from non-pregnant and pregnant buffalos. methods: steroids was extracted using liquid extraction, enzyma...

Gonadal steroids have traditionally been found to have short-term effects on the mating behavior of adult vertebrates, such that increased steroid hormone levels influence behavior over the course of a few days. Long-term effects also have been observed in which embryonic exposure to steroid hormone influences the sexual behavior of adults. The generality of the paradigms that have resulted fro...

Among the small group of species (e.g., some temperate zone turtles, snakes, and bats) that exhibit a dissociated reproductive pattern, the red-sided garter snake (Thamnophis sirtalis parietalis) is probably the most well studied. For these species, courtship and mating occur immediately upon emergence from winter dormancy; the gonads remain essentially inactive. Male red-sided garter snakes ar...

Do men die young and sick, or do women live long and healthy? By trying to explain the sexual dimorphism in life expectancy, both biological and environmental aspects are presently being addressed. Besides age-related changes, both the immune and the endocrine system exhibit significant sex-specific differences. This review deals with the aging immune system and its interplay with sex steroid h...

SYNOPSIS. Research on the sexual differentiation of mating behavior has impeded progress in our understanding of the proximate bases of individual differences in two ways. First, by viewing variation as categorical rather than continuous, and second, by not placing sufficient emphasis on the fact that males and females differ genetically in many vertebrates, environmental contributions to indiv...

Gonadal steroid hormones act in the brain to elicit changes in gene expression that result in profound effects on behavior and physiology. A variety of in vitro studies indicate that nuclear receptor coactivators are required for efficient transcriptional activity of steroid receptors. Two nuclear receptor coactivators, steroid receptor coactivator-1 (SRC-1) and cAMP response element binding pr...

It has been shown that some of the mycotic infections especially systemic mycoses show increased male susceptibility and some steroids have been known to influence the immune response. Researchers found that some fungi including yeasts use "message molecules" including hormones to elicit certain responses, especially in the sexual cycle, but until recently no evidence was available to...