Perinatal Kafein Uygulamasının Yavru Sıçanların Beyin Dokusundaki Seks Steroit Hormonları Üzerine Etkisi

Abstract

Most of the anatomical, physiological and neurochemical gender-related differences in the brain occur prenatally. Testosterone, estradiol and dihydrotestosterone are the main sex steroid hormones responsible for the organization and sexual differentiation of brain structures during early development. Caffeine is a psychoactive substance widely consumed in the world via coffee, chocolate, beverages, food and some therapeutics. Caffeine is a nonselective adenosine antagonist having neuroprotective effects. Hypothalamo-pituitary-adrenocortical axis, gonads and adrenal cells, including adenosine receptors, have a key role in the synthesis of sex steroid hormones. Since caffeine might affect the metabolic pathways in these structures through adenosine receptor antagonism we aimed to investigate the possible modulatory effects of the mother's caffeine consumption (low or high dose) on sex steroid hormones of brain tissue in the fetuses or pups. In the present study, rats were treated either with low dose (0.3 g/L) or high dose (0.8 g/L) caffeine in their drinking water during their pregnancy and lactation period. Testosterone, estradiol, and dihydrotestosterone levels in the frontal cortex and hypothalamus were measured by using radioimmunoassay method at embryonic day 19, neonatal day and postnatal day 4. Adrenal gland weights, anogenital distance (in fetuses and pups), gonad weights and serum free testosterone level (in pups) were also measured. Our findings showed that low dose caffeine administration increased body weights in both male and female rats and anogenital index in male rats at postnatal day 4. Furthermore, high dose caffeine administration decreased adrenal weight in male rats on embryonic day 19 and increased testosterone level in the frontal cortex of female fetuses and hypothalami of male newborn rats. In conclusion, the effects of caffeine administration on sex steroids in the brain tissue during the perinatal period are dose-related and these effects seem to be independent of the peripheral steroid sources.