Faculty Research 1990 - 1999

Title

Dexamethasone-induced hyperglycemia in obese Avy/a (viable yellow) female mice entails preferential induction of a hepatic estrogen sulfotransferase.

Document Type

Article

Publication Date

1994

Keywords

Blood-Glucose: me, Corticosterone, Dexamethasone, Estradiol, Female, Hyperglycemia: ci, Insulin, Liver: en, Male, Mice, Mice-Obese, Obesity: co, RNA-Messenger: me, Sulfotransferases: bi, SUPPORT-NON-U-S-GOVT, Transcortin: ge

JAX Source

Diabetes 1994 Aug;43(8):999-1004

Abstract

Sex steroid sulfotransferases (ST) sulfurylate and thus inactivate estrogens or androgens, producing an androgenized or estrogenized state in the liver. The expression of diabetes in a number of animal models is sexually dimorphic and has been associated with steroidal states. Although the viable yellow (Avy) mutation produces an insulin-resistant obesity syndrome in mice of both sexes, only males develop chronic hyperglycemia. Hyperglycemia was rapidly induced in Avy/a females by dexamethasone (dex). This treatment completely suppressed both endogenous plasma corticosterone and hepatic corticosterone-binding globulin (CBG) mRNA within 24 h. Hyperglycemia in dex-implanted Avy/a females was accompanied by aberrant shifts in hepatic androgen/estrogen balance. This was effected by induction of estrogen sulfotransferase (EST) mRNA together with a > 10-fold increase in enzymatic activity. Similar dex-induced increases in androgen ST or phenol ST were not observed. Prior implantation of estrogen prevented development of hyperglycemia. The time-dependent spontaneous reversal of dex-induced hyperglycemia correlated with re-expression of CBG mRNA transcripts and reduced levels of EST transcripts and enzyme activity. Although dex-induced hyperglycemia was limited to Avy/a females, dex elicited hyperinsulinemia in lean a/a control mice of both sexes and exacerbated constitutive hyperinsulinemia in Avy/a males and females. In summary, dex-induced hyperglycemia in Avy/a females was associated with increased catabolism of hepatic estrogens mediated by induction of EST.

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