Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 3902067

Captopril mediated decrease of aortic regurgitation.

S N Reske·I Heck·J Kropp·H Mattern·R Ledda·R Knopp·C Winkler
View original source ↗Export metadata ↓

Abstract

The effect of captopril mediated afterload reduction on aortic regurgitation was investigated in 10 patients. Regurgitation was quantitated by means of the regurgitation fraction and the relation of regurgitant volume to end diastolic volume. These variables were derived from gated radionuclide ventriculography. After captopril treatment the blood concentration of angiotensin I rose whereas that of angiotensin II fell significantly. The conversion of angiotensin I to II was reduced to about 50% of the control value. Whereas blood pressure and heart rate did not change significantly, the regurgitation fraction and the regurgitant volume, normalised to end diastolic volume, were significantly reduced by captopril treatment. The ejection fraction remained essentially unchanged. These findings suggest that captopril reduces aortic regurgitation by reducing afterload.

Explore related subjects

Angiotensin IAngiotensin IIAortic Valve InsufficiencyBlood PressureCaptoprilHeart RateHumansRadioimmunoassayStroke VolumeJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S N Reske, I Heck, J Kropp, H Mattern, R Ledda, R Knopp, C Winkler. 1985. Captopril mediated decrease of aortic regurgitation.. https://doi.org/10.1136/hrt.54.4.415

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

The two homologous domains of human angiotensin I-converting enzyme interact differently with competitive inhibitors.

The endothelial angiotensin I-converting enzyme (ACE; EC 3.4.15.1) has recently been shown to contain two large homologous domains (called here the N and C domains), each being a zinc-dependent dipeptidyl carboxypeptidase. To further characterize the two active sites of ACE, we have investigated their interaction with four competitive ACE inhibitors, which are all potent antihypertensive drugs. The binding of [3H] trandolaprilat to the two active sites was examined using the wild-type ACE and four ACE mutants each containing only one intact domain, the other domain being either deleted or inactivated by point mutation of the zinc-coordinating histidines. In contrast with all the previous studies, which suggested the presence of a single high affinity inhibitor binding site in ACE, the present study shows that both the N and C domains of ACE contain a high affinity inhibitor binding site (KD = 3 and 1 X 10(-10) M, respectively, at pH 7.5, 4 degrees C, and 100 mM NaCl). Chloride stabilizes the enzyme-inhibitor complex for each domain primarily by slowing its dissociation rate, as the k-1 values of the N and C domains are markedly decreased (about 30- and 1100-fold, respectively) by 300 mM NaCl. At high chloride concentrations, the chloride effect is much greater for the C domain than for the N domain resulting in a higher affinity of this inhibitor for the C domain. In addition, the inhibitory potency of captopril (C), enalaprilat (E), and lisinopril (L) for each domain was assayed by hydrolysis of Hip-His-Leu. Their Ki values for the two domains are all within the nanomolar range, indicating that they are all highly potent inhibitors for both domains. However, their relative potencies are different for the C domain (L greater than E greater than C) and the N domain (C greater than E greater than L). The different inhibitor binding properties of the two domains observed in the present study provide strong evidence for the presence of structural differences between the two active sites of ACE.

Angiotensin I↗
PubMed1992

Laser desorption studies of high mass biomolecules in Fourier-transform ion cyclotron resonance mass spectrometry.

Matrix-assisted laser desorption ionization is used to obtain Fourier-transform ion cyclotron resonance mass spectra of model peptides (e.g., gramicidin S, angiotensin I, renin substrate, melittin, and bovine insulin). Matrix-assisted laser desorption ionization yields ions having appreciable kinetic energies. Two methods for trapping the high kinetic energy ions are described: (i) the ion signal for [M+H]+ ions is shown to increase with increasing trapping voltages, and (ii) collisional relaxation is used for the detection of [M+H]+ ions of bovine insulin.

Angiotensin I↗
PubMed1992

Comparison of angiotensin-converting enzyme inhibitors in the rat in perfused hindlimbs and in vivo.

To investigate the role of local renin angiotensin systems in the functional responses to angiotensin I and II, the effects of angiotensin I and angiotensin II on resistance were measured in perfused hindlimbs of rats under normal conditions and during infusion of enalaprilate, lisinopril, zabiciprilate and captopril at two infusion rates. The angiotensin-converting enzyme (ACE) inhibitors significantly increased ED50 and decreased maximal resistance changes of angiotensin I dose dependently, without effects on angiotensin II responses. Captopril increased the ED50 of angiotensin I significantly more than did the other ACE inhibitors at a low infusion rate. The ACE inhibitors, except for lisinopril, increased the ED50 of angiotensin I pressor responses in vivo to the same extent, and were similarly potent to inhibit plasma ACE activity at 15 min after injection. The ratio of the doses of the ACE inhibitors used in vivo was the same as in perfused hindlimbs. These results suggest that, in the hindlimbs, angiotensin I causes ACE-dependent vasoconstriction. Captopril may be more effective to inhibit local ACE than the other ACE inhibitors investigated.

Angiotensin I↗