Role of metabotropic glutamate receptors in ventrolateral medulla of hypertensive rats

Abstract

Evidence is accumulating for the role of metabotropic, as well as ionotropic, glutamate receptors in cardiovascular regulation. We sought to determine whether stimulation of metabotropic glutamate receptors in the rostral ventrolateral medulla would evoke enhanced cardiovascular responses in spontaneously hypertensive rats (SHR). Thus, we microinjected (1S,3R)-1- aminocyclopentane-1,3-dicarboxylic acid [(1S,3R)-ACPD], a selective agonist of metabotropic glutamate receptors, into the rostral ventrolateral medulla of urethane-anesthetized adult SHR and age-matched Wistar-Kyoto (WKY) rats. Microinjection of (1S,3R)-ACPD (1 nmol/50 nL) produced increases in mean arterial pressure and splanchnic sympathetic nerve activity in SHR (+41±6 mm Hg and +34±4%, respectively) that were significantly greater than those observed in WKY rats (+18±3 mm Hg and +22±3%, P