Effect of chronic ACTH treatment on guinea-pig adrenal steroidogenesis: steroid plasma levels, steroid adrenal levels, activity of steroidogenic enzymes and their steady-state mRNA levels.
J Steroid Biochem Mol Biol
; 41(1): 69-78, 1992 Jan.
Article
en En
| MEDLINE
| ID: mdl-1310416
ABSTRACT
We report here the effects of a 7-day treatment of guinea-pigs with ACTH on adrenal mRNA levels for steroid-transforming enzymes. Adrenal 3 beta-hydroxysteroid dehydrogenase 4-ene-5-ene-isomerase (3 beta-HSD), 17-hydroxylase, 17,20-lyase, 21-hydroxylase and 11-hydroxylase activities were also examined as well as plasma and adrenal steroid levels. Our data reveal that chronic ACTH-treatment stimulated all post-pregnenolone enzyme activities in glomerulosa-fasciculata cells. Plasma steroid levels increased 8 h after the last injection of ACTH and returned to the control levels 24 h later whereas, in the adrenal, the content in steroids in the group sacrificed 8 h after the last injection of ACTH were similar to the values of the control group and decreased markedly 24 h later. It is suggested that the steroid turn-over in the adrenal may be affected by the chronic ACTH-treatment. On the other hand, despite the significant stimulation in steroid-transforming enzyme activities, our data reveal that chronic ACTH administration caused a decrease in mRNA levels for P450c21 and P450c17 while P450scc, 3 beta-HSD and P450c11 remained unchanged. Taken together, these results suggest that in vivo chronic ACTH-treatment of guinea-pigs increases adrenal steroidogenic capacity by increasing steroid secretion and steroid enzyme activity. Moreover, the chronic treatment with ACTH may have a post-transcriptional effect on steroidogenic enzymes gene expression by affecting the half-life of their mRNAs.
Buscar en Google
Bases de datos:
MEDLINE
Asunto principal:
Esteroide Hidroxilasas
/
Esteroides
/
ARN Mensajero
/
Enzima de Desdoblamiento de la Cadena Lateral del Colesterol
/
Corticoesteroides
/
Glándulas Suprarrenales
/
Hormona Adrenocorticotrópica
/
Sistema Enzimático del Citocromo P-450
/
Aldehído-Liasas
/
3-Hidroxiesteroide Deshidrogenasas
Límite:
Animals
Idioma:
En
Revista:
J Steroid Biochem Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Año:
1992
Tipo del documento:
Article
País de afiliación:
Canadá