Arginine-vasopressin and corticotropin-releasing hormone are sequentially involved in the endothelin-1-induced acute stimulation of rat pituitary-adrenocortical axis.
The acute effect of endothelin-1 (ET-1) on the hypothalamo-pituitary-adrenal (HPA) axis has been investigated in the rat. The plasma concentrations of arginine-vasopressin (AVP), ACTH, aldosterone and corticosterone have been measured by RIA 30 and 60 min after ET-1 administration. ET-1 (2.0 nmol kg(-1) raised AVP plasma concentration at both 30 and 60 min. ET-1 did not alter the ACTH plasma level at 30 min, but markedly increased it at 60 min. ACTH response was unaffected by the simultaneous administration of AVP-receptor antagonists (AVP-As) Des-Gly-[Phaa1,D-Tyr(Et)2,Lys6,Arg8]-vasopressin or [Deamino-Pen1,Tyr(Me)2,Arg8]-vasopressin (20 nmol kg(-1), but abolished by the corticotropin-releasing hormone (CRH)-receptor antagonist alpha-helical-CRH(9-41) (alpha-CRH, 10 nmol kg(-1). ET-1 evoked significant rises in the blood levels of aldosterone and corticosterone at both 30 and 60 min. AVP-As abrogated the response at 30 min, while alpha-CRH was ineffective. Both AVP-As and alpha-CRH partially reversed adrenocortical secretory response at 60 min. Collectively, these findings confirm that systemically administered ET-1 stimulates rat HPA axis, and provide evidence that the mechanism underlying this effect may involve the sequential activation of AVP and CRH release.
Malendowicz
L K
LK
Department of Histology and Embryology, School of Medicine, Poznan, Poland.
Belloni
A S
AS
Nussdorfer
G G
GG
Hochol
A
A
Nowak
M
M
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000450:Aldosterone / Q000097:blood; D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists; D001127:Arginine Vasopressin / Q000031:analogs & derivatives / Q000097:blood*; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D019332:Endothelin-1 / Q000494:pharmacology*; D005260:Female; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D065092:Antidiuretic Hormone Receptor Antagonists; D019332:Endothelin-1; D001127:Arginine Vasopressin; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D003345:Corticosterone