Retinoic acid stimulates growth hormone synthesis in human somatotropic adenoma cells: characterization of its nuclear receptors.
In order to gain a better understanding on the possible role of retinoic acid (RA) on human GH secretion, we have characterized the expression of its nuclear receptors in somatotropic adenoma cell extracts. By immunoblotting with rabbit polyclonal antibodies directed against RAR alpha, beta, and gamma and RXR alpha and beta, we could only detect the presence of RAR alpha and RXR alpha proteins. The predominant expression of RXR alpha was confirmed at the mRNA level by Northern and slot-blot analysis. We then investigated the effect of RA on GH synthesis in cell culture of adenomatous somatotrophs. In cultured cells, RA (1 microM) stimulated GH secretion, increased intracellular GH content and GH mRNA levels within 72 h, suggesting a modulation of GH synthesis by RA.
Guibourdenche
J
J
Unité INSERM 427, Faculté des Sciences Pharmaceutiques et Biologiques, Université René Descartes Paris V, France.
Djakouré
C
C
Porquet
D
D
Pagésy
P
P
Rochette-Egly
C
C
Peillon
F
F
Li
J Y
JY
Evain-Brion
D
D
D000172:Acromegaly; D000236:Adenoma / Q000235:genetics*; D000328:Adult; D015153:Blotting, Western; D002478:Cells, Cultured; D005260:Female; D019382:Human Growth Hormone / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D047488:Retinoid X Receptors; D014157:Transcription Factors / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*
D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D019382:Human Growth Hormone; D014212:Tretinoin