[Role of rostral ventrolateral medulla in the "renzhong" induced pressor response in rabbits].

Experiments were performed on 14 rabbits locally anesthetized with procaine. Both vagus nerves were cut. The animals were immobilized with gallamine trithiodide and maintained by artificial ventilation. The effects of electrical stimulation of "Renzhong" area on arterial blood pressure and heart rate were observed before and after microinjection of kainic acid (KA) into rostral ventrolateral medulla (RVL). Electrical stimulation of "Renzhong" area could elicit a very marked increase in arterial blood pressure, before microinjection of KA into RVL. Bilateral microinjection of KA (0.5 microgram, an excitotoxin) into RVL could essentially abolish the pressor effect of stimulation of "Renzhong" area. However, bilateral microinjection of NS into RVL showed no effects on the pressor effect of stimulation of "Renzhong" area. These results suggest that RVL plays a key role in the pressor effect of "Renzhong" area stimulation.