[Character of organ volume vessels during pressor reflexes]

In acute experiments on cats, responses of the resistance and capacity vessels of small intestine, spleen, kidneys, and m. gastrocnemius were studied during pressor sinocarotid reflex and electrical stimulation of the sciatic and brachial afferents. It was shown that, against the background of constrictory responses of the resistance vessels in these organs, both the constrictory and the dilatory responses of the capicitance vessels could occur or not. Correlation analysis revealed no dependence between the markedness and character of the capacitance vessel responses and the changes of the venous blood oxygenation during pressor reflexes. The regulatory mechanisms determining, different characters of the capacitance vessels during neurogenic effects and the methodical conditions revealing the true nature of changes occurring in the postcapillary bed, are discussed.