Atrial and brain natriuretic peptide in right atrium myocytes in the postreperfusion period in rat

Abstract

We have studied the accumulation and excretion of atrial (ANP) and brain (BNP) natriuretic peptides in the early and late postreperfusion period (60 min and 60 days) in the myocardium of the right atrium in rats. The model of total ischemia proposed by Korpachev et al. (1982) was used. Immunocytochemical localization of peptides in cardiomyocytes was performed on ultrathin sections using the polyclonal antibodies. The intensities of accumulation (excretion) of ANP and BNP were analyzed by counting the immunolabeled granules (types A and B) with a transmission electron microscope. At 60 min and 60 days of the postreperfusion period, an increase in the synthesis and release of ANP and BNP was found. A more pronounced BNP reaction could be explained by the fact that, under normal conditions, the main hormone of the natriuretic peptide system regulating blood pressure is ANP, while BNP regulates blood pressure in cardiovascular pathology.