Angiotensin-converting enzyme in pericardial fluid: comparative study with serum activity.

Background: The characterization of an angiotensin-converting enzyme (ACE) in human pericardial fluid is relevant, considering its role in the angiotensin II release and thus, the role of the pericardium in cardiovascular homeostasis.

Objective: To isolate and characterize an ACE from human pericardial fluid and to compare the angiotensin I converting activities of the pericardial fluid with that of the serum in patients submitted to cardiovascular surgery.

Methods: The enzyme from human pericardial fluid was purified through chromatographic steps and characterized by polyacrylamide gel electrophoresis (SDS-PAGE), hydrolysis of angiotensin I, bradykinin, Hip-His-Leu and synthetic substrates with internal fluorescence suppression.

Correlations between the collagen content of the human left ventricular myocardium, measured by biochemical and morphometric methods.

Objective: To assess, in myocardium specimens obtained from necropsies, the correlation between the concentration of hydroxyproline, measured with the photocolorimetric method, and the intensity of fibrosis, determined with the morphometric method.

Methods: Left ventricle myocardium samples were obtained from 45 patients who had undergone necropsy, some of them with a variety of cardiopathies and others without any heart disease. The concentrations of hydroxyproline were determined with the photocolorimetric method.