AV3V lesions attenuate the cardiovascular responses produced by blood-borne excitatory amino acid analogs

Departments of Pharmacology and Psychology and Cardiovascular Center, University of Iowa, Iowa City, Iowa 52242 Systemic injections of the excitatory amino acid (EAA) analogs, kainic acid (KA) and N -methyl- D -aspartate (NMDA), produce a pressor response in conscious rats that is caused by a centrally mediated activation of sympathetic drive and the release of arginine vasopressin (AVP). This study tested the hypothesis that the tissue surrounding the anteroventral part of the third ventricle (AV3V) plays a role in the expression of the pressor responses produced by systemically injected EAA analogs. Specifically, we examined whether prior electrolytic ablation of the AV3V region would affect the pressor responses to KA and NMDA (1 mg/kg iv) in conscious rats. The KA-induced pressor response was smaller in AV3V-lesioned than in sham-lesioned rats (11 ± 2 vs. 29 ± 2 mmHg; P