3-巯基丙酮酸转硫酶在新生大鼠延髓的表达和宫内香烟烟雾暴露对其表达的影响

Objective To investigate the expression of 3-mercaptopyruvate sulfurtransferase (3MST) in medulla oblongata of neonatal rats and effects of intrauterine cigarette exposure on its expression. Methods Sprague Dawley pregnant rats were randomly divided into 2 groups, control group and cigarette smoke exposure group. 3MST mRNA and protein expression in medulla oblongata of neonatal rats were analysed by RT-PCR and Western blotting, respectively, and the expression of 3MST in the neurons of respiratory-related nuclei in medulla oblongata of neonatal rats was investigated with immunohistochemical technique. Results The RT-PCR and Western blotting analyses showed that 3MST mRNA and protein were expressed in the medulla oblogata of neonatal rats and intrauterine cigarette exposure promoted their expression (P<0.05). Immunohistochemical staining indicated that 3MST existed in the neurons of pre-B?tzinger complex (pre-B?tC), hypoglossal nucleus (12N), ambiguous nucleus (Amb), facial nucleus (FN) and nucleus tractus solitarius (NTS) in control group of the animals and the mean optical densities of 3MST-positive neurons in the pre-B?tC, 12N, Amb and FN, but not NTS, were significantly increased in cigarette smoke exposure group (P<0.05). Conclusions 3MST exists in the neurons of medullary respiratory nuclei of neonatal rats and its expression can be up-regulated by intrauterine cigarette exposure, suggesting that the 3MST-H2S pathway may be involved in protection of medullary respiratory centers against injury induced by intrauterine cigarette exposure.