Periventricular anteroventral third ventricle lesions diminish the pressor response produced by systemic injection of the N-methyl-D-aspartate receptor antagonist MK-801.
This study examined whether electrolytic ablation of the periventricular anteroventral third ventricle (AV3V) would affect the increases in mean arterial blood pressure (MAP) and heart rate (HR) in conscious rats produced by systemic injection of the centrally acting N-methyl-D-aspartate (NMDA) receptor ion-channel blocker, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5, 10-imine (MK-801; 250 microgram/kg, i.v.). MK-801 produced a smaller increase in MAP in rats with AV3V lesions than in sham-lesion rats (+36+/-2% vs. +52+/-5%, respectively, P<0.05). In contrast, MK-801 produced similar increases in HR in the AV3V- and sham-lesion rats (+28+/-3% vs. +22+/-4%, respectively, P>0.05). These findings demonstrate that the MK-801-induced pressor response is dependent upon the integrity of the AV3V region, whereas the MK-801-induced tachycardia is not.
Whalen
E J
EJ
Department of Pharmacology, University of Iowa, Iowa City, IA 52242-1109, USA.
Beltz
T G
TG
Lewis
S J
SJ
Johnson
A K
AK
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002552:Cerebral Ventricles / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate