[Changes in the concentration of plasma cardionatrin and morphological changes of atrial cardiocytes after severe burn].

The purpose of this experiment is to investigate the changes in plasma concentration cardionatrin of and morphological changes in atrial cardiocytes in rats after severe burn by means of radioimmunoassay, immunocytochemistry, electron microscopy and morphometry. The results showed that: (1) At 1, 2 h postburn the plasma cardionatrin concentrations were significantly increased, at 6-48 h significantly decreased and at 72, 168 h returned to normal. (2) The changes in plasma cardionatrin concentration were related to the alterations of secretory function in atrial cardiocytes. (3) The pathological changes in atrial cardiocytes were characterized by appearing early. The pathological changes and alterations of secretory function of atrial cardiocytes ran a dynamic course, which could be roughly divided into three phases, the phase of stress, the phase of secretory inhibition and injury, and the phase of recovery. (4) It might be one of the forms of atrial cardiocytes secreting cardionatrin that the atrial specific granules with intact limiting membrane were excreted from the defect of plasmalemma.