[QUANTITATIVE ANALYSIS OF BRAIN NATRIURETIC PEPTIDE OF CARDIAC MUSCLE CELLS IN EARLY POSTREPERFUSION PERIOD IN RATS]

The intensity of accumulation and release of brain natriuretic peptide (BNP) in right atrial cardiac muscle cells was investigated in rats after 5 and 60 min from the reperfusion start. Total ischemia was simulated by cardiovascular bundle compression according to V. G. Korpachev. Immunocytochemical identification of BNP in atrial myocyte granules was investigated in ultrathin cuts. We applied polyclonal antibodies to BNP. The calculation of granules (A- and B-types) with BNP was carried out in (38 x 38 μm) visual fields in transmission electronic microscope. The results were assessed using Mann-Whitney U-test (p < 0.05). After 5 min from the reperfusion start, the amount of the granules with BNP did not change compared to intact animals rate. On the 60th min of the post-reperfusion period was shown active accumulation and release of BNP; the amount of A-type granules increased by 134%, B-type granules increased by 210 % in comparison with intacy level. The results showed stimulating effect of ischemic and reperfusion factors on the processes of the brain natriuretic peptide synthesis and secretion in the early post-reperfusion period.