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.
Department of Histology and Embryology, School of Medicine, Poznan, Poland.
L K
LK
Malendowicz
A S
AS
Belloni
G G
GG
Nussdorfer
A
A
Hochol
M
M
Nowak
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