Elevated levels of plasma vasoactive intestinal peptide in human acute myocardial infarction.

The plasma levels of vasoactive intestinal peptide in peripheral vein were measured in human acute myocardial infarction. The plasma vasoactive intestinal peptide level was increased within 1 h after the onset of the symptoms of acute myocardial infarction (Group 1, n = 9), compared with normal values (6.3 +/- 0.7 vs. 2.8 +/- 0.9 pg/ml, P < 0.05). Two or more hours after the onset of acute myocardial infarction there was no subsequent increase in peripheral plasma vasoactive intestinal peptide levels (n = 26). Ten days after the onset of acute myocardial infarction, the elevated plasma vasoactive intestinal peptide levels in Group 1 had normalized (3.5 +/- 0.5 pg/ml).