Effects of estrogen and testosterone on the metabolism of mevalonate by the shunt pathway.
Mevalonate is metabolized by a sterol-forming and a non-sterol-forming, also called the "shunt", pathway. Effects of estrogen and testosterone administration on the shunt activity were examined in male and female Wistar and Sprague-Dawley rats. Shunt activity was determined in vivo from the yield of expired 14CO2 following [5-14C]mevalonate injection. Total mevalonate utilized was determined from the yield of expired 14CO2 following [1-14C]mevalonate injection. In the female, about 45% of mevalonate appears to be metabolized via the shunt, and in the male about 20%. This difference between male and female rats is dependent on both testosterone and estrogen, and apparently on testosterone to a greater extent. Thus estrogen treatment produced a 20-35% increase in shunt activity over castrated controls, while castration of males without hormonal treatment resulted in about a 50% increase in shunt activity, and testosterone administration returned castrated male and female shunt activity to that of intact males, or nearly so. Light/dark cycle had no effect in vivo on shunt activity, but may be critical in demonstrating sex differences in shunt activity in kidney slices.
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D002369:Castration; D002940:Circadian Rhythm; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D007668:Kidney / Q000378:metabolism; D008297:Male; D008798:Mevalonic Acid / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D013739:Testosterone / Q000494:pharmacology*
D004967:Estrogens; D002245:Carbon Dioxide; D013739:Testosterone; D008798:Mevalonic Acid