Mediation of vagal cardioinhibitory responses by glutamatergic receptors in the caudal medulla of turtles.

Our previous studies showed that electrical stimulation of the nuclei ambiguous (NA) or dorsomotor nuclei of the vagus (DMV) complex in the brain stem of spontaneously breathing pond turtles (Cyclemys fiavomarginata), anesthetized with chloralose (4 mg/100 g) and urethane (40 mg/100 g), produced a marked slowing or even cessation of the heart rate, and resulted in an immediate fall of blood pressure. Results of the present study further demonstrated that the cardioinhibitory responses could also be elicited by microinjection of monosodium glutamate (0.2-20 nl, 50 mM) into the NA/DMV complex in turtles.

Kynurenic acid attenuates multiorgan dysfunction in rats after heatstroke.

Aim: To assess whether systemic delivery of kynurenic acid improves the outcomes of heatstroke in rats.

Methods: Anesthetized rats were divided into 2 major groups and given vehicle solution (isotonic saline 0.3 mL/kg rat weight) or kynurenic acid (30-100 mg in 0.