Testosterone Effect on Insulin Content, Messenger Ribonucleic Acid Levels, Promoter Activity, and Secretion in the Rat*
| Autor: | Cristina Fernandez-Mejia, Nestor Morales-Peza, Vicente Díaz-Sánchez, Guillermo Romero-Navarro, Sumiko Morimoto |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Chloramphenicol O-Acetyltransferase
Male medicine.medical_specialty medicine.medical_treatment Carbohydrate metabolism Biology Transfection Adenoviridae Islets of Langerhans Endocrinology Internal medicine Insulin Secretion medicine Hyperinsulinemia Animals Insulin Testosterone Pancreatic islet function RNA Messenger Rats Wistar Promoter Regions Genetic geography geography.geographical_feature_category Pancreatic islets Hyperandrogenism Blotting Northern medicine.disease Islet Rats Glucose medicine.anatomical_structure Plasmids |
| Zdroj: | Endocrinology. 142:1442-1447 |
| ISSN: | 1945-7170 0013-7227 |
| DOI: | 10.1210/endo.142.4.8069 |
| Popis: | Coexistence of hyperinsulinemia and hyperandrogenism in women has been frequently described. Most of the studies addressing this issue have focused on the mechanisms by which insulin produces hyperandrogenism. In the present study, we analyzed the effects of testosterone in vivo and in vitro upon insulin gene expression and release in the rat. Our studies demonstrate that testosterone increases insulin messenger RNA (mRNA) levels in vitro as well as in vivo. In both prepuberal and intact adult rats, serum testosterone concentrations were positively correlated with insulin mRNA levels and insulin concentration in serum. Testosterone deprivation after gonadectomy decreased both insulin gene expression and serum insulin concentration. Insulin mRNA levels were partially restored after 3 days of testosterone administration and serum insulin was 80% and 27% above baseline values at 5 and 7 days posttreatment. Primary cultured pancreatic islets treated with the sexual steroid increased about 80% insulin mRNA, as well as protein, and release. In transfected islets, testosterone increased the activity of the −410 bp rat insulin promoter I by 154%. These data demonstrate that testosterone has a direct effect upon pancreatic islet function by favoring insulin gene expression and release. |
| Databáze: | OpenAIRE |
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