Physiological and drug-induced changes in blood levels of adrenal steroids and their precursors in cynomolgus monkeys: An application of steroid profiling by LC-MS/MS for evaluation of the adrenal toxicity.
The adrenal gland is the most common toxicological target of drugs within the endocrine system, and inhibition of adrenal steroidogenesis can be fatal in humans. However, methods to evaluate the adrenal toxicity are limited. The aim of the present study was to verify the usefulness of simultaneous measurement of blood levels of multiple adrenal steroids, including precursors, as a method to evaluate drug effects on adrenal steroidogenesis in cynomolgus monkeys. With this aim, physiological and drug-induced changes in blood levels of adrenal steroids, including cortisol, aldosterone, androgen, and their precursors were examined. First, for physiological changes, intraday and interday changes in blood steroid levels were examined in male and female cynomolgus monkeys. The animals showed circadian changes in steroid levels that are similar to those in humans, while interday changes were relatively small in males. Next, using males, changes in blood steroid levels induced by ketoconazole and metyrapone were examined, which suppress adrenal steroidogenesis via inhibition of CYP enzymes. Consistent with rats and humans, both ketoconazole and metyrapone increased the deoxycorticosterone and deoxycortisol levels, probably via CYP11B1 inhibition, and the increase was observed earlier and with greater dynamic range than the changes in cortisol level. Changes in other steroid levels reflecting the drug mechanisms were also observed. In conclusion, this study showed that in cynomolgus monkeys, simultaneous measurement of blood levels of adrenal steroids, including precursors, can be a valuable method to sensitively evaluate drug effects on adrenal steroidogenesis and to investigate the underlying mechanisms.
['Tochitani|Tomoaki|T|', 'Yamashita|Akihito|A|', 'Matsumoto|Izumi|I|', 'Kouchi|Mami|M|', 'Fujii|Yuta|Y|', 'Yamada|Toru|T|', 'Miyawaki|Izuru|I|']
D000311:Adrenal Glands D000450:Aldosterone D000728:Androgens D000818:Animals D002853:Chromatography, Liquid D002940:Circadian Rhythm D003900:Desoxycorticosterone D005260:Female D006801:Humans D006854:Hydrocortisone D007654:Ketoconazole D008252:Macaca fascicularis D008297:Male D008797:Metyrapone D013252:Steroid 11-beta-Hydroxylase D053719:Tandem Mass Spectrometry
Cynomolgus monkey Adrenal steroidogenesis In vivo Liquid chromatography-tandem mass spectrometry Simultaneous measurement of multiple steroids