Chronic ACE-inhibitor treatment and adrenergic mechanisms in spontaneously hypertensive rats

Journal of Cardiovascular Pharmacology
M CastellanoE A Rosei

Abstract

We investigated the effects of chronic treatment with the angiotensin-converting enzyme (ACE) inhibitor fosinopril on cardiac and vascular noradrenergic neurotransmission as related to cardiovascular hypertrophy in spontaneously hypertensive rats (SHRs). SHRs were treated with fosinopril at "high dose" (SHR-HD, 25 mg/kg/day) or "low dose" (SHR-LD, 1 mg/kg/day) from the 6th to the 12th week of age, and compared to age-matched untreated SHRs (SHR-C) and Wistar-Kyoto controls (WKY). Blood pressure was significantly reduced in SHR-HD but not in SHR-LD when compared to SHR-C. The antihypertensive dose of fosinopril reduced both cardiac and vascular hypertrophy, whereas the low dose was effective only in reducing vascular hypertrophy. Several differences in presynaptic and postsynaptic cardiovascular noradrenergic neurotransmission were observed between SHR-C and WKY rats (increased cardiac norepinephrine concentration, down-regulation of cardiac beta-adrenoceptors, reduced alpha-adrenergic receptor-mediated vasoconstrictor response of small mesenteric arteries to exogenous norepinephrine). All these differences were abolished by ACE inhibitor treatment, both at antihypertensive or at subantihypertensive doses. The results of this st...Continue Reading

Related Concepts

Related Feeds

Adrenergic Receptors: Trafficking

Adrenergic receptor trafficking is an active physiological process where adrenergic receptors are relocated from one region of the cell to another or from one type of cell to another. Discover the latest research on adrenergic receptor trafficking here.

Antihypertensive Agents: Mechanisms of Action

Antihypertensive drugs are used to treat hypertension (high blood pressure) which aims to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Discover the latest research on antihypertensive drugs and their mechanism of action here.

Cardiovascular Disease Pathophysiology

Cardiovascular disease involves several different processes that contribute to the pathological mechanism, including hyperglycemia, inflammation, atherosclerosis, hypertension and more. Vasculature stability plays a critical role in the development of the disease. Discover the latest research on cardiovascular disease pathophysiology here.

Cardiomegaly

Cardiomegaly, known as an enlarged heart, is a multifactorial disease with different pathophysiological mechanisms. Hypertension, pregnancy, exercise-induced and idiopathic causes are some mechanisms of cardiomegaly. Discover the latest research of cardiomegaly here.