Effect of carotid sinus reflex on the circulation of rats bearing Guérin carcinoma.

The effect of carotid occlusion was studied on cardiac output (Evans blue dilution) and its fractional distribution (Sapirstein's isotope fractionation technique) in rats with and without Guérin carcinoma. In response to the carotid sinus hypertensive reflex (CSHR), in normal rats blood pressure and TPR were augmented; vascular resistance of the kidneys, intestines, skin and carcass was increased. In tumour bearing rats CSHR resulted in comparable increments of vascular resistance in various organs. Tumour blood flow remained unchanged, whereas vascular resistance of the tumour was considerably increased.