Effect Of Hydrogen Sulfide On Arterial Baroreflex In Septic Rat

Objective:To investigate the potential role of hydrogen sulfide (H2S) in regulating arterial baroreflex (ABR) in septic rats. Methods:This study was conducted in the rat model of cecal ligation and puncture-induced (CLP) sepsis.53 male Spargue-Dawley rat were randomized into 10 groups:①SO+NS intravenous injection group;②SO+NaHS intravenous injection group;③CLP+NaHS intravenous injection group;④CLP(PAG)+NaHS intravenous injection group;⑤SO+aCSF bilater NTS microinjection group;⑥SO+NaHS bilater NTS microinjection group;⑦SO+vehicle (DMSO)+NaHS group;⑧SO+Gli+NaHS group;⑨CLP+vehicle (DMSO) group;⑩CLP+Gli group. ABR function was measured before and 5 min and 30 min after administration. Another 37 male rats were randomized into 4 groups:normal, SO, CLP, CLP (PAG) group, and the plasma cortisol content were detected in this study. Results:Compared with SO+NaHS intravenous injection group, ABR value before administration of CLP+NaHS intravenous injection group showed significant decrease (P<0.05). Compared with ABR before administration, ABR value of SO+NaHS intravenous injection group, CLP+NaHS intravenous injection group and CLP(PAG)+NaHS intravenous injection group fell 5 min and 30 min after intravenous H2S donor NaHS (0.28 mg/kg) (P<0.05; P<0.01). Compared with SO+aCSF bilater NTS microinjection group, ABR value of SO+NaHS bilater NTS microinjection group received significant decrease 5 min and 30 min after administration (P<0.01). Compared with SO+vehicle+NaHS group, SO+Gli+NaHS group showed ABR ameliorated after administration (P<0.05). Subsequently, compared with CLP+vehicle group, CLP+Gli group also received ABR ameliorated after administration (P<0.05). Compared with normal, SO or CLP (PAG) rat, the plasma cortisol of CLP rat showed significant increase in content (P<0.05; P<0.01). Conclusion: Endogenous H2S played an adverse role in septic ABR function, and opening KATP channel located at the pathway of ABR, may be the mechanism involved in the down-regulation of ABR function in septic rat. Notably, the nucleus tractus solitarii (NTS), as the primary gate of ABR, may be also responsible for the reducion of ABR function induced by intra-NTS NaHS. In addition, the plasma cortisol may participate in effect of H2S on ABR function.