Testosterone effect on insulin content, messenger ribonucleic acid levels, promoter activity, and secretion in the rat
Por:
Morimoto S., Fernandez-Mejia C., Romero-Navarro G., Morales-Peza N., Diaz-Sanchez V.
Publicada:
1 ene 2001
Resumen:
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.
Filiaciones:
Morimoto S.:
Depto. Biologia de la Reproduccion, Inst. Nac de Cie. Med. Nutr. SZ, Vasco de Quiroga 15, Tlalpan 14000, D.F. Mexico City, Mexico
Fernandez-Mejia C.:
Depto. Biologia de la Reproduccion, Inst. Nac de Cie. Med. Nutr. SZ, Vasco de Quiroga 15, Tlalpan 14000, D.F. Mexico City, Mexico
Romero-Navarro G.:
Depto. Biologia de la Reproduccion, Inst. Nac de Cie. Med. Nutr. SZ, Vasco de Quiroga 15, Tlalpan 14000, D.F. Mexico City, Mexico
Morales-Peza N.:
Depto. Biologia de la Reproduccion, Inst. Nac de Cie. Med. Nutr. SZ, Vasco de Quiroga 15, Tlalpan 14000, D.F. Mexico City, Mexico
Diaz-Sanchez V.:
Depto. Biologia de la Reproduccion, Inst. Nac de Cie. Med. Nutr. SZ, Vasco de Quiroga 15, Tlalpan 14000, D.F. Mexico City, Mexico
All Open Access; Bronze
|