ABSTRACT
The dynamics of blood plasma corticosterone, testosterone and androstenedione levels and their reaction to acute stress (30 min immobilization) in 35-, 40- and 45-day old female rats exposed to chronic stress (daily 30-min immobilization from 35th to 45th day of life) and/or to excess of exogenous androgens (implantation of capsules with testosterone to 33-day old animals) during pubescence was studied. Both control and experimental females in all age groups responded to acute stress by significant elevation of blood plasma corticosterone levels. At the end of the chronic stress session, the extent of adrenals activation in response to acute dosed stress was lowered in androgenized 45-day old females and increased gradually in stressed ones. After acute stress, the blood plasma testosterone level decreased in control 35-day old females and rose - in androgenized females against 10-fold rising of basal hormonal level. In 40-day old control females as well as in androgenized ones exposed to chronic stress during 5 days, the acute dosed stress did not result in significant changes of blood plasma testosterone and elevated blood plasma androstenedione. Stressed 40-day old females with increased basal androstenedione secretion did not respond to acute stress by the hormone level changes while blood plasma testosterone declined significantly. At the end ofpubescence (on the 45th day of life), acute stress did not affect the blood plasma testosterone level in control and androgenized animals, while decreased it in stressed females and increased - in androgenized rats exposed to chronic stress against elevated basal level of the hormone. The conclusion is made about possible functional relationship between the changes in hormonal homeostasis during pubescence and development of reproductive system in mature animals.
Subject(s)
Adrenal Glands/drug effects , Androgens/administration & dosage , Androstenedione/blood , Corticosterone/blood , Sexual Maturation/drug effects , Testosterone/blood , Adrenal Glands/physiology , Animals , Drug Implants , Female , Humans , Immobilization , Rats , Rats, Wistar , Sexual Maturation/physiology , Stress, Physiological/drug effectsABSTRACT
Effects of chronic stress (daily 30-min immobilization) on 35-45 days of life and its combination with androgenization (implantation of testosterone-containing capsules on 33rd day of life) on reproductive system of 2.5 month old female rats were studied. The term of sexual maturation, estrous cycles regularity and structure, blood plasma levels of testosterone, progesterone and androstenedione as well as ovarian histology were examined. Androgenization resulted in the blood plasma testosterone level increase and the androstenedione level decrease, development of oligo- or anovulatory condition characterized by disorders or discontinuation in estrous cyclicity. We also detected abrupt reduction or absence of postovulatory luteal bodies, cysts formation and ovarian interstitial tissue overgrowth. All experimental animals had normal blood plasma corticosterone level. Stressed rats had no considerable changes in reproductive system except of some cyclicity disorders. Stressed against androgenization rats demonstrated delayed pubescence, an increased number of ovarian cysts along with attenuation ofandrogenization-caused negative effects on the sexual cyclicity.