Open AccessEndothelin Antagonism Does Not Affect Adrenal Catecholamine Secretion and System Haemodynamics During Acute Stress in Wistar Rats
Author(s) -
Dmitry V. Zaretsky,
Maria V. Zaretskaia,
Е. И. Каленикова,
Mikhail A. Grafov
Publication year - 2000
Publication title -
journal of cardiovascular pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.762
H-Index - 100
eISSN - 1533-4023
pISSN - 0160-2446
DOI - 10.1097/00005344-200036051-00108
Subject(s) - catecholamine , epinephrine , endocrinology , medicine , norepinephrine , hemodynamics , adrenal medulla , endothelin receptor , adrenal gland , receptor , dopamine
In the present work we evaluated the role of circulating endothelin-1 (ET-1) in haemodynamics and the adrenal medulla responses to stress using PD-142893, a mixed endothelin-A- and -B- (ET(A)/ET(B)) receptor antagonist. Male Wistar rats were chronically instrumented with arterial and venous catheters and a microdialysis probe placed into the adrenal medulla. Stress was induced by a 1 h period of immobilization. PD-142893 was infused (20 microg/kg/min) for 90 min starting 30 min before stress onset. Concentrations of norepinephrine and epinephrine in dialysate samples were measured by high-performance liquid chromatography (HPLC). At rest animals displayed a stable level of norepinephrine (85 +/- 34 pg/ml) and epinephrine (176 +/- 57 pg/ml) in adrenal perfusate and constant haemodynamic parameters. Stress increased adrenal secretion (norepinephrine 206 +/- 50%, epinephrine 202 +/- 45%) associated with hypertension (peak 141 +/- 3 mmHg) and tachycardia (peak 505 +/- 5 bpm). No significant changes in haemodynamics or of plasma catecholamine levels were observed during infusion of PD-142893. The antagonist did not significantly change the stress-induced increase in catecholamine secretion, tachycardia or hypertension. Thus, in Wistar rats, circulating ET-1 seems not to be essential for blood pressure control or adrenal catecholamine secretion during acute stress.