Abstract: ObjectiveTo investigate the effect and mechanisms of rostral ventrolateral medulla (RVL) on the pressor response of lateral hypothalamus-perifornical region (LH/PF) in rats.Methods30 healthy Wistar rats were randomly divided into four groups: the phentolamine group; propranolol group; atropine group and glutamate diethyl ester group, saline was as the control in every group. After microinjection of Glu into LH/PF, the blood pressure and heart rate were observed. Then phentolamine, propranolol, atropine and glutamate diethyl ester were microinjected into RVL and the blood pressure and heart rate changes induced by microinjection of Glu were observed again.ResultsMicroinjection of Glu into LH/PF can cause the blood pressure elevating and heart rate accelerating. The pressor response of Glu to excited LH/PF could be attenuated after response of phentolamine, propranolol, atropine and glutamate diethyl ester microinjected into RVL. The blood pressures of phentolamine group; propranolol group; atropine group and glutamate diethyl ester group reduced significantly different from those in the saline control group (P<0.01).ConclusionThe α-,β-,M- and Glu-receptors in the RVL induce the pressor response of LH/PF region.

Key words: rostral ventrolateral medulla (RVL), lateral hypothalamus-perifornica (LH/PF), pressor response, rats