Localization of alpha-1 acid glycoproteins in human myocardium

alpha-1 acid glycoproteins become elevated in the patient's serum within a few hours after an acute myocardial infarction. Previous reports have suggested a correlation between the magnitude of this elevation and infarct size as estimated by enzyme markers. Correlation has also been observed between the mortality following infarction and appearance of elevated alpha-1 acid glycoproteins. We now report that these glycoproteins are detectable in normal myocardium using immunohistochemical techniques. Diminished amounts are observed in necrotic tissue in acute myocardial infarcts. Ultrastructural localization by immunoelectron microscopy using sections of normal myocardium established the presence of alpha-1 acid glycoproteins primarily at the cell surface in the region of the sarcolemma. The observations suggest that myocardium may directly contribute to the elevation of serum alpha-1 acid glycoproteins after an infarct, and the assessment of these components may serve as an additional serum marker.