Microinjection of D-2-amino-7-phosphonoheptanoate into the dorsal periaqueductal gray matter reduces the pressor response to glutamate injected at the same site.
The current study assesses the influence of the N-methyl-D-aspartate (NMDA) receptor antagonist D-2-amino-7-phosphonoheptanoate (AP7) on the pressor effect of glutamate microinjected into the dorsal periaqueductal gray matter (DPAG) of urethane-anesthetized rats. Glutamate (20, 40 and 80 nmol/site) caused dose-related reproducible increases in systolic and diastolic blood pressure. Microinjection of saline into the DPAG did not alter the pressor effects of glutamate (80 nmol/site). Similar pretreatment with AP7 (2 nmol/site) significantly (P less than 0.05) attenuated the pressor effects of glutamate from +26.5 +/- 7.0 to +3.4 +/- 3.3 mmHg (systolic blood pressure). We conclude that the pressor effect of glutamate in the DPAG is mediated largely by activation of NMDA receptors.
Batista-Da-Silva
A P
AP
Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brasil.
Rae
G A
GA
Carobrez
A P
AP
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives*; D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates / Q000008:administration & dosage; D008297:Male; D008845:Microinjections; D010487:Periaqueductal Gray / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012119:Respiration / Q000187:drug effects
D000596:Amino Acids; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D015763:2-Amino-5-phosphonovalerate; C031231:2-amino-7-phosphonoheptanoic acid