Effect of arotinolol on hemodynamics and plasma atrial natriuretic peptide at rest and during stress in spontaneously hypertensive rats.
We investigated the effects of chronic treatment with arotinolol, a beta-blocker with weak alpha-blocking potency, on hemodynamics and plasma levels of catecholamines and atrial natriuretic peptide (ANP) at rest and during stress in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. At rest, arotinolol treatment decreased mean arterial pressure (MAP), cardiac index (CI) and heart rate (HR), with no changes in total peripheral resistance index or regional hemodynamics in SHR. Acute stress caused more remarkable hemodynamic changes in SHR. During stress, arotinolol decreased MAP, CI and HR, and reduced myocardial and skeletal muscle flow and splanchnic, renal, cerebral and cutaneous vascular resistance in SHR. Arotinolol's effects were much less in WKY. Stress also increased the plasma catecholamine and ANP levels in SHR. Arotinolol raised these hormones in both strains at rest and in SHR during stress. Thus, arotinolol treatment exerted greater suppressive effects on the resting and stressed hemodynamics in SHR, with associated increases in the plasma catecholamine and ANP levels.
Yamamoto
J
J
Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Osaka, Japan.
Matsubara
H
H
Nakai
M
M
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood*; D006352:Heart Ventricles; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D009206:Myocardium / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D011412:Propanolamines / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR / Q000033:anatomy & histology / Q000502:physiology*; D011919:Rats, Inbred Strains / Q000502:physiology*; D011921:Rats, Inbred WKY; D012146:Rest; D013312:Stress, Physiological / Q000097:blood / Q000503:physiopathology*
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C024523:arotinolol; D009320:Atrial Natriuretic Factor