Mevalonate, an essential intermediate in cholesterol synthesis, is metabolized either to cholesterol or, by the shunt pathway, to CO2. Previous investigations have demonstrated that the kidneys are the chief site of circulating mevalonate metabolism and that sex hormones as well as insulin markedly influence circulating mevalonate metabolism. The present study examined in rats the influence of thyroid hormone status on mevalonate metabolism in vivo and in vitro. L-thyroxine administration increased renal conversion of circulating mevalonate to cholesterol, 41% in the females and 22% in the males. Conversely, hypothyroidism induced by 6 N propyl-2-thiouracil reduced renal conversion of circulatng mevalonate to cholesterol by 45% in females and 27% in males; thyroid hormone replacement in these animals returned cholesterogenesis in the kidneys to supranormal levels. Neither L-thyroxine nor hypothyroidism altered circulating mevalonate conversion to cholesterol in the liver or carcass. In vitro studies confirmed the in vivo observations. Changes in thyroid hormone produced only minor changes in the shunt pathway of mevalonate metabolism. This study demonstrates that the major effect of the thyroid hormone on the metabolism of circulating mevalonate is to alter the conversion of mevalonate to cholesterol, an effect localized solely to the kidneys.
K R Feingold, M H Wiley, G MacRae, M D Siperstein
Usage data is cumulative from May 2023 through May 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 90 | 0 |
67 | 16 | |
Scanned page | 121 | 0 |
Citation downloads | 11 | 0 |
Totals | 289 | 16 |
Total Views | 305 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.