OBJECTIVE: To study the metabolism of @entity1812 (BK) after a single passage through the coronary bed in isolated Langendorff @entity35 hearts. METHODS: BK was infused into the aortic flow line to obtain a final concentration of 10 nM, and the coronary, effluent was collected to quantify BK and des-Arg9-BK by competitive enzyme immunoassay. The nature of immunoreactive material was confirmed by immunograms after @entity1172 . The experiments were performed with hearts perfused at either one of the following coronary flow rates: 1, 5 or 10 ml/min. RESULTS: BK recovery without inhibitors was 86.3 +/- 2.9, 60.8 +/- 6.3, and 29.6 +/- 6.8% at 10, 5, and 1 ml/min, respectively. The Vmax/Km ratios at these coronary flow rates were 2.19 +/- 0.72, 4.81 +/- 0.64, and 2.59 +/- 0.33 min-1 g-1), respectively. The @entity1811 ( @entity1811 ) inhibitor, enalaprilat (130 nM), reduced BK degradation at all flow rates. Inhibition of neutral endopeptidase with retrothiorphan (25 nM) had no effect on BK degradation. However, the combined treatment with @entity4688 and @entity69663 reduced BK degradation to lower values than enalaprilat alone. The effect of enzyme inhibitors on BK recovery was inversely related to coronary flow: inhibiting BK degradation markedly increased BK recovery at 1 ml/min, but had no effect at 10 ml/min. The kininase I metabolite of BK, des-Arg9-BK, could not be detected under these experimental conditions. CONCLUSIONS: @entity1811 is the major enzyme responsible for BK degradation during a single passage through the coronary bed. Neutral endopeptidase contributes to BK degradation only when @entity1811 activity is impaired. The effect of enzyme inhibitors on the coronary concentration of BK is highly dependent on coronary flow rate.

Metabolism of XXXX by the @entity35 coronary vascular bed.

@entity1811 :: ('24310(Tax:10116)', 'Gene') :: ['ACE', 'angiotensin-converting enzyme'] @entity4688 :: ('MESH:D004656', 'Chemical') :: ['enalapril'] @entity69663 :: ('MESH:C072559', 'Chemical') :: ['retrothiorphan'] @entity1172 :: ('MESH:D001010', 'Disease') :: ['HPLC separation'] @entity1812 :: ('MESH:D001920', 'Chemical') :: ['bradykinin'] @entity35 :: ('10116', 'Species') :: ['rat']
@entity1812 :: (MESH:D001920,Chemical) :: ['bradykinin']
