Myocardial tissue blood flow in allotransplanted rat heart with a special reference to acute rejection

To evaluate the severity of acute rejection of the homologous heart, myocardial tissue blood flow was measured after a heterotopic heart transplantation in rats. The autograft group (Lewis to Lewis) and the allograft group (DA to Lewis) were compared by graft survival time, myocardial tissue blood flow, myocardial water content, and degrees of histologic alterations. Average graft survival times were longer than 100 days in the autograft group and 5.9 +/- 0.4 days in the allograft group. In the autograft group, myocardial tissue blood flows on postoperative days 1 and 5 were 206 +/- 12 and 189 +/- 18 ml/min/100 gm myocardial wet weight in the left ventricle and 205 +/- 11 and 188 +/- 12 ml/min/100 gm myocardial wet weight in the right ventricle, respectively. In the allograft group, myocardial tissue blood flows on postoperative days 1, 3, and 5 were 222 +/- 30, 164 +/- 22, and 141 +/- 49 ml/min/100 gm myocardial wet weight in the left ventricle and 202 +/- 17, 156 +/- 15, and 147 +/- 46 ml/min/100 gm myocardial wet weight in the right ventricle, respectively. Myocardial tissue blood flows in both ventricles showed significant decreases on days 3 and 5 as compared with those on day 1. Myocardial water content did not alter significantly by day 5 in the autograft group, registering 77.9% +/- 0.6% and 78.4% +/- 1.6%. Myocardial water contents in the allograft group increased significantly as rejection progressed.(ABSTRACT TRUNCATED AT 250 WORDS)