Acute hypotensive responses to peptide inhibitors of renin in conscious monkeys: an effect on blood pressure independent of plasma renin inhibition.

In order to investigate the hypotensive mechanisms of action of peptide renin inhibitors, blood pressure responses to five renin inhibitors were compared with those to the angiotensin converting enzyme inhibitor, enalaprilat, in conscious African green and rhesus monkeys. (3S-4S)-4-amino-5-cyclohexyl-3-hydroxy pentanoic acid (ACHPA)-containing renin inhibitory peptide (ACRIP) and enalaprilat both decreased blood pressure in euvolemic and volume-depleted African green monkeys. However, while a maximum dose of enalaprilat reduced blood pressure to 80 +/- 4 and 56 +/- 4 mmHg in the euvolemic and volume-depleted monkeys, respectively, ACRIP lowered pressure to life-threatening levels (less than 40 mmHg) under both conditions. The relative potencies of ACRIP and four other renin inhibitors for inhibiting in vitro plasma renin activity (PRA; IC50) were compared with their potencies in reducing blood pressure by 15 mmHg (ED15 mmHg) and lowering blood pressure more than enalaprilat in volume-depleted rhesus monkeys. All renin inhibitors lowered blood pressure significantly beyond the maximal response to enalaprilat. Despite a significant correlation (r = 0.99, P less than 0.05) between the in vitro PRA inhibitory potency and the in vivo ED15 mmHg, doses which lowered blood pressure beyond the maximal responses to enalaprilat were not significantly correlated (r = 0.53, P greater than 0.05) with the in vitro PRA IC50 values. Furthermore, the profound depressor responses to renin inhibitors in rhesus monkeys were accompanied by increases in the heart rate and decreases in pulse pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Zinc sulfate in acne vulgaris.

The effects of orally administered zinc sulfate in 52 patients with mild to moderate acne vulgaris were compared to those of a placebo capsule. The numbers of comedones, papules, pustules, infiltrates, and cysts were counted at each visit over a 12-week period. Forty patients completed the study. Zinc appeared to have a somewhat beneficial effect on pustules but not on comedones, papules, infiltrates, or cysts. Fourteen patients (50%) in the zinc group had side effects of nausea, vomiting, or diarrhea. Six patients (21%) in the zinc group could not tolerate the nausea and withdrew from the study.