RELATION BETWEEN CHANGES IN BLOOD-PRESSURE AND SERUM ACE ACTIVITY AFTER A SINGLE-DOSE OF ENALAPRIL AND ACE GENOTYPE IN HEALTHY-SUBJECTS

1 The effects of a single oral dose of enalapril 10 mg on serum ACE ac tivity and blood pressure in relation to the ACE genotype were studied in 27 healthy men, n = 9 each of genotype DD, ID and II, in a paralle l group study design. 2 Before treatment serum ACE activity differed s ignificantly between the genotypes, with serum ACE activity 56% higher in DD than II subjects, and the genotype explaining 40% of between-su bject variance in serum ACE activity. 3 After oral enalapril 10 mg the absolute fall in serum ACE activity was significantly larger in DD th an II subjects at 2, 4, and 6 h (by 9.0 (95% CI 0.7-17.2), 10.7 (3.8-1 7.6), and 9.7 (2.8-16.6) nmol ml(-1) min(-1) respectively), but not at 24 h (fall in II > DD by 1.1 (-8.9 to 6.7) nmol ml(-1) min(-1)). 4 Se rum ACE activity remained significantly related to the ACE genotype at each time-point after enalapril, with the genotype explaining 22-46% of between subject variance in serum ACE. 5 Falls in mean arterial pre ssure in response to enalapril were not significantly related to the A CE genotype, with the average fall over 6 h in DD > II genotype by 0.7 mm Hg (95% CI -5.5 to 4.1). 6 Blood pressure responses to enalapril d id not correlate significantly with the initial serum ACE, or the abso lute or percent reductions in serum ACE activity after enalapril. 7 In itial serum ACE and serum ACE responses to enalapril are strongly infl uenced by the ACE genotype, but these variables do not predict the blo od pressure response to enalapril under these experimental conditions.