P14 The cardiovascular functions of hydrogen sulfide within the caudal ventrolateral medulla are related with the opening of KATP channels and activation glutamate receptors mechanisms

Abstract

Objective To observe the cardiovascular functions of hydrogen sulfide (H2S) within the caudal ventrolateral medulla (CVLM) and to explore its mechanisms in rats. Methods Sixty-seven male SD rats were employed in present study. Among them, 34 rats were randomized into control group (aCSF, 100 nL, n = 6), NaHS group (sodium hydrosulfide, NaHS, 2, 20 or 200 pmol, n = 7 for each dose), S-ademetionine (SAM, 10 nmol, n = 7). In 33 rats, hydroxylamine (HA, n = 7), kynurenic acid (KYN, n = 7) or glibenclamide (GLI, n = 7) were prior applied before NaHS (20 pmol) was microinjected into the CVLM. Results Unilateral microinjection of NaHS (2 to 200 pmol), a H2S donor, into the CVLM caused the transient and dose-dependent hypotension and bradycardia (P Conclusion These data support the hypothesis that endogenous H2S produces cardiovascular inhibition functions in the CVLM, mainly mediated by KATP channels opening mechanism.