Inhibition of testicular steroidogenesis in the neonatal rat following acute ethanol exposure.
We have previously reported detrimental effects of in utero ethanol exposure on testicular steroidogenic enzyme activity in newborn rats. It is now reported that in utero ethanol exposure during Day 12 of gestation through birth has no apparent morphological effect on the testes of Day 1 neonatal rats. It appears that the detrimental effects of ethanol on testicular steroidogenesis can be manifested at the biochemical level in the absence of morphological effects. However, it remained unknown as to whether acute exposure to ethanol would elicit similar biochemical effects as chronic ethanol exposure on testicular steroidogenesis. To test this possibility ethanol was injected at 0, 1, or 2 g/kg intraperitoneally (IP) into rats of various postnatal ages. Plasma ethanol and testosterone levels as well as testicular 17 alpha-hydroxylase and C17,20-lyase activities were measured. The results indicate that acute exposure to ethanol significantly (p less than 0.05) inhibits the catalytic activity of testicular 17 alpha-hydroxylase in the newborn rat testis. This inhibition was specific since the activity of testicular C17,20-lyase was not affected. In conjunction with the reduction in testicular enzyme activity, plasma testosterone levels were reduced to 30% of the control levels in newborn animals receiving ethanol. In older animals, i.e., postnatal Day 20 and 40 rats, plasma testosterone levels were reduced, but not significantly, following ethanol treatment. Furthermore, testicular enzyme activity was not significantly reduced following ethanol treatment in these same older animals. These results suggest that the newborn rat testis is especially sensitive to the effects of ethanol.
Kelce
W R
WR
Department of Veterinary Biomedical Sciences, University of Missouri-Columbia 65211.
Ganjam
V K
VK
Rudeen
P K
PK
D000375:Aging; D000446:Aldehyde-Lyases / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D005865:Gestational Age; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D011919:Rats, Inbred Strains; D013254:Steroid 17-alpha-Hydroxylase / Q000037:antagonists & inhibitors; D013256:Steroids / Q000096:biosynthesis*; D013737:Testis / Q000033:anatomy & histology / Q000187:drug effects / Q000201:enzymology*; D013739:Testosterone / Q000097:blood
D013256:Steroids; D000431:Ethanol; D013739:Testosterone; D003577:Cytochrome P-450 Enzyme System; D013254:Steroid 17-alpha-Hydroxylase; D000446:Aldehyde-Lyases