Effects of captopril related to increased levels of prostacyclin and angiotensin-(1-7) in essential hypertension

J Hypertens. 1996 Jun;14(6):799-805. doi: 10.1097/00004872-199606000-00017.


Objective: To evaluate the contribution of angiotensin-(1-7) [Ang-(1-7)] and prostaglandins to the acute and long-term antihypertensive actions of captopril in mild-to-moderate essential hypertensive patients.

Design and methods: Blood pressure, cardiac rate and the plasma concentrations of angiotensin I (Ang I), angiotensin II (Ang II), Ang-(1-7), prostaglandin E2 and 6-keto prostaglandin F1 alpha (the breakdown product of prostacyclin) were determined in the peripheral venous blood of 24 essential hypertensive subjects before and 3 h after administration of 50 mg captopril. Eleven of 24 patients completed a 6-month treatment period with captopril monotherapy (50 mg twice a day). The hemodynamic and hormonal response produced by a last 50 mg dose of captopril was determined once again in the 11 subjects who maintained blood pressure control with captopril monotherapy for 6 months.

Results: The fall in blood pressure produced 3 h after drug intake was comparable for the first and the last 50 mg captopril dose. Although the first response to captopril increased plasma levels of Ang I only, the response to the last dose of the drug (6 months after) caused significantly higher levels of Ang I and Ang-(1-7). Neither acute nor chronic therapy with captopril had a significant effect on plasma concentrations of Ang II. Although plasma levels of prostaglandin E2 and 6-keto prostaglandin F1 alpha were not modified by a first exposure to captopril, the concentrations of 6-keto prostaglandin F1 alpha but not prostaglandin E2 rose significantly in subjects treated with the inhibitor for 6 months. A negative correlation was also demonstrated between diastolic blood pressure and plasma Ang-(1-7) levels in the 11 essential hypertensive subjects in whom blood pressure was controlled with captopril monotherapy.

Conclusions: Inhibition of angiotensin converting enzyme with captopril had a significant effect on blood pressure that was not directly accounted for by a suppression of plasma Ang II levels. Continuous therapy with captopril unmasked a contribution of Ang-(1-7) and prostacyclin to the antihypertensive actions of this drug.

Publication types

  • Clinical Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Angiotensin I
  • Angiotensin II / blood*
  • Angiotensin-Converting Enzyme Inhibitors / therapeutic use*
  • Antihypertensive Agents / therapeutic use*
  • Captopril / therapeutic use*
  • Epoprostenol / blood*
  • Female
  • Humans
  • Hypertension / blood*
  • Hypertension / drug therapy*
  • Male
  • Middle Aged
  • Peptide Fragments / blood*
  • Time Factors


  • Angiotensin-Converting Enzyme Inhibitors
  • Antihypertensive Agents
  • Peptide Fragments
  • Angiotensin II
  • Angiotensin I
  • Captopril
  • Epoprostenol
  • angiotensin I (1-7)