Effect of Antihypertensive Treatment on Structure and Function of Resistance Arteries in Essential Hypertensive Patients

Abstract

Altered structure and function of resistance arteries may play a role in the maintenance of elevated blood pressure and in the pathogenesis of its complications. In order to evaluate the effects of antihypertensive drugs on resistance arteries, seventeen male untreated mild essential hypertensive patients participated in a double-blind randomized trial comparing an angiotensin converting enzyme inhibitor, cilazapril, and a beta blocker, atenolol. Blood pressure before treatment was similarly elevated in both groups of patients (148±4/99±1 mmHg). Patients were treated with either cilazapril 2.5−5 mg per day or atenolol 25−100 mg per day. At 1 year of treatment blood pressure was 131± 2/86±1 mmHg in both groups of patients. Resistance arteries dissected from gluteal subcutaneous fat biopsies obtained before treatment and at one year showed that media/lumen ratio of arteries from patients treated with cilazapril was reduced to 6.3± 0.2% from 7.5±0.3% before treatment (p<0.05), whereas in arteries from patients treated with atenolol there was no significant difference (8.0±0.6% before and 8.1±0.5% after 1 year of treatment). Depressed media stress responses to norepinephrine, arginine vasopressin and endothelin-1 were normalized in patients on cilazapril but were unchanged in those on atenolol. Thus, treatment for one year with a converting enzyme inhibitor corrects in part the structural and functional abnormalities present in subcutaneous resistance arteries of patients with mild essential hypertension.