[Changes in the substance P content of the blood and hypothalamus during experimental emotional stress].

A study was made of the content of substance P in the blood and hypothalamus of Wistar rat brain in acute and chronic emotional stress and after intraperitoneal injection of substance P in a dose of 250 mg/kg. A possibility was demonstrated of inducing long-term changes in the content of substance P in the hypothalamus after a single injection. Exposure to a single 24-hour stress was followed by an increase in the substance P content in the hypothalamus.

[Self-stimulation reaction in normotensive and hypertensive rats].

The part of noradrenergic mechanisms in self-stimulation (SS) operant behaviour was studied in rats. In all experiments systolic blood pressure (BP) in the tail artery was measured by means of photocells. It was found, that small doses of noradrenaline facilitate the SS, while high doses depress or stop it.