How an animal performs in its natural environment ultimately plays a key role in its reproductive success. While a number of studies have investigated how selection acts on performance-related traits, far fewer studies have examined the mechanisms responsible for variation in performance. Among mechanisms, variable morphology has received the most attention. Although physiological traits have r...

The paper analyzes the scientific data included the author's own results about the opportunities to increase the reproductive potential of female animals by application of the natural no hormonal substances and the supposed mechanisms of their action on the reproductive system. Also the new scientific data related to the discovering of the "metabolic" hormones (leptin, ghrelin) and kisspeptin/G...

AIM This study was conducted to understand whether serum level of the steroid and metabolic hormones may be indicative of their level in ovarian follicular fluid (FF) in porcine, and its influence on fertility. MATERIALS AND METHODS Ovaries from pigs (n=32) of two genetic groups, namely, native (Ghungroo; n=16) and crossbred (Hampshire × Ghungroo; n=16) were collected. Both the genetic groups...

The aim of this study was to test the hypothesis that antecedent short-term administration of estradiol or progesterone into the central nervous system (CNS) reduces levels of neuroendocrine counterregulatory hormones during subsequent hypoglycemia. Conscious unrestrained male Sprague-Dawley rats were studied during randomized 2-day experiments. Day 1 consisted of an 8-h lateral ventricle infus...

The uterine endometrium is exquisitely sensitive to hormones, in particular estrogen and progesterone and to a lesser extent androgens and glucocorticoids. These hormones tightly regulate the complex functioning of the female reproductive tract and are intimately involved in controlling the growth, development, and remodeling of reproductive tissues as well as the cyclic changes that occur duri...

Hormones are crucial systemic players and act at different sites of the entire body including the brain. The brain is not only the target of hormone action, but also serves as the “conductor” of the “neuro-endocrine symphony”. Changes in neuronal activity, such as seizures in epileptic patients, may affect hormonal regulation and secretion. In turn, hormones modify susceptibility to develop sei...

Physiological responses and control of body systems differ between women and men. Moreover, within women, female gonadal hormones have important influences on organs and systems outside of reproduction. Until the NIH Revitalization Act of 1993, laboratories focused physiological research primarily on men, and this focus placed limitations on women's health care. Thus, the NIH directive to inclu...

Three experiments were conducted to test whether testicular hormones secreted during puberty masculinize and defeminize the expression of adult reproductive behavior. Experiment 1 tested the hypothesis that gonadal hormones during puberty masculinize behavioral responses to testosterone (T) in adulthood. Male hamsters were castrated either before puberty (noTduringP) or after puberty (TduringP)...