[Pressor reflexes and changes in sympathetic impulsation and the responses of intestinal and renal vessels]

In acute experiments on cats, the ganglio-blocking agent (hexonium 2 mg/kg) revealed no high-amplitude impulsation (over 15 mcV) in the branches of intestinal and kidney nerves. Simultaneously, no responses of the small intestine and kidney resistance vessels to constriction of the carotid arteries were observed. The constrictory and dilatory responses of the capacitance vessels in the same organs, after the above dose of the ganglioblocking agent, are preserved and correlated with the character of changes of the lowamplitude (equal to or lower than 15 mcV) impulsation persisting in the intestinal and kidney nerves. The post-ganglionar sympathetic fibers conducting high-amplitude discharges are suggested to be mainly responsible for the reflex responses of the resistance vessels, while the low-amplitude fibers--for responses of the capacitance vessels.