Mitochondrial K(ATP) channels contribute to the protective effects of hydrogen sulfide against impairment of central chemoreception of rat offspring exposed to maternal cigarette smoke

We previously reported that maternal cigarette smoke (CS) exposure resulted in impairment of central chemoreception and induced mitochondrial dysfunction in offspring parafacial respiratory group (pFRG), the kernel for mammalian central chemoreception. We also found that hydrogen sulfide (H(2)S) could attenuate maternal CS exposure-induced impairment of central chemoreception in the rat offspring in vivo. Mitochondrial ATP sensitive potassium (mitoK(ATP)) channel has been reported to play a significant role in mitochondrial functions and protect against apoptosis in neurons. Thus, we hypothesize here that mitoK(ATP) channel plays a role in the protective effects of H(2)S on neonatal central chemoreception in maternal CS-exposed rats. Our findings revealed that pretreatment with NaHS (donor of H(2)S, 22.4mM) reversed the central chemosensitivity decreased by maternal CS exposure, and also inhibited cell apoptosis in offspring pFRG, however, 5-HD (blocker of mitoK(ATP) channels, 19mM) attenuated the protective effects of NaHS. In addition, NaHS declined pro-apoptotic proteins related to mitochondrial pathway apoptosis in CS rat offspring pFRG, such as Bax, Cytochrome C, caspase9 and caspase3. NaHS or 5-HD alone had no significant effect on above indexes. These results suggest that mitoK(ATP) channels play an important role in the protective effect of H(2)S against impairment of central chemoreception via anti-apoptosis in pFRG of rat offspring exposed to maternal CS.