[Prospective study of the effects of an angiotensin converting enzyme inhibitor and a beta blockader on the structure and function of resistant arteries in mild essential hypertension].

Seventeen male untreated mild essential hypertensive patients with a mean age of 41 years agreed to participate in a double-blind randomized trial to test the effects of treatment with cilazapril, an inhibitor of angiotensin I converting enzyme, in comparison to treatment with atenolol, a beta-blocker, on the structure and function of subcutaneous resistance arteries. Patients were randomized to receive either cilazapril 2.5-5 mg or atenolol 25-100 mg per day per day. Blood pressure before treatment was 147/99 and 148/99 mmHg in both groups respectively. At 1 year of treatment blood pressure was 132/86 and 131/85 mmHg in both groups of patients respectively. Treatment for one year with cilazapril resulted in a reduction in the media/lumen ratio of resistance arteries (150-400 microns lumen diameter) dissected from subcutaneous gluteal biopsies from 7.5 +/- 0.3% before treatment to 6.3 +/- 0.2% 1 year later (p < 0.05), still slightly but significantly larger (p < 0.05) than the media/lumen ratio of resistance arteries of normotensive controls (5.1 +/- 0.3%). In arteries from patients treated with atenolol there was no significant change with treatment (8.0 +/- 0.6% before and 8.1 +/- 0.5% after 1 year of treatment). Active wall tension responses to endothelin-1 were blunted in hypertensive patients and normalized in the cilazapril-treated patients, but were unchanged in those taking atenolol. Relaxation in response to acetylcholine of norepinephrine pre-contracted arteries was still significantly reduced after one year (< 0.05) in comparison to those of normotensive patients in the patients treated with atenolol, whereas they were not in those who had received cilazapril.(ABSTRACT TRUNCATED AT 250 WORDS)