Exercise test: trend of the leukocyte flow properties, polymorphonuclear membrane fluidity and cytosolic Ca2+ content in normals, in subjects with previous acute myocardial infarction and in subjects with aortocoronary by-pass.

We evaluated, during an exercise test, the leukocyte flow properties, the polymorphonuclear leukocyte (PMN) membrane fluidity and PMN cytosolic Ca2+ content in normals, in subjects with previous acute myocardial infarction (AMI) and in subjects previously submitted to a aortocoronary by-pass. Leukocyte flow properties were evaluated using the St. George filtrometer. Examination of the PMN membrane fluidity was effected employing the probe TMA-DPH; while evaluation of the PMN cytosolic Ca2+ content was carried out using the probe Fura 2-AM. At baseline, in both cardiopathic groups a significant difference in PMN filtration parameters and in PMN cytosolic Ca2+ content was evident compared to normals. In normals, at peak of exercise, there was an evident reduction of mononuclear filtration parameters, while during recovery a slight increase of the PMN cytosolic Ca2+ content was observed. In subjects with previous AMI and in subjects with aortocoronary by-pass, however, we observed, at peak of exercise, a decrease of the mononuclear filtration parameters, a reduction of the PMN membrane fluidity and an increase of the PMN cytosolic Ca2+ content. In both groups, the changes in PMN membrane fluidity and cytosolic Ca2+ content remained during recovery. The trend of the PMN membrane fluidity and cytosolic Ca2+ content found in the cardiopathic subjects during the exercise test suggest the PMN activation may be more evident in these subjects.