Effect of haemorrhagic hypotension on the circulation of rats with Guérin carcinoma.

After transplanting Guérin carcinoma in rats the cardiac output (Evans-blue dilution), the distribution of cardiac output (Sapirstein's isotope indicator fractionation technique), the nutritive blood flow of the organs, and their circulatory resistance were investigated in haemorrhagic hypotension (40 or 70 mm Hg). The posthaemorrhagic redistribution of cardiac output in tumor-bearing rats was similar to that found in normal bled animals: the renal and skin fractions of cardiac output decreased and that of the brain, myocardium, and carcass increased. As a result of bleeding the decrease of the tumor fraction of cardiac output was the greatest compared to the other organs. Thus the tumor seems to be the main target organ of the posthaemorrhagic redistribution.