RESUMO
OBJECTIVE: The aim of this study was to investigate the role of dexmedetomidine (Dex) in lactate signaling cascade and myocardial ischemia/reperfusion (I/R) injury in mice. MATERIALS AND METHODS: The left anterior descending of the coronary artery was ligatured for 30 min and then reperfused for 6 h to induce myocardial I/R injury in mice. Heart samples were collected and the levels of lactate, SOD and MDA were measured. Infarct size and myocardium were stained with triphenyltetrazolium chloride and TUNEL, respectively. In addition, the expression levels of MCT1, cytochrome c, cleaved caspase-9 and -3 were detected by Western blot. RESULTS: The myocardial infarct size, lactate and MDA levels of the I/R group were significantly increased, whereas the SOD activity was decreased. However, Dex significantly reduced the myocardial infarct size, as well as lactate and MDA levels in contrast to the I/R group. Meanwhile, the SOD activity was remarkably increased. The expression levels of MCT1, cytochrome c, cleaved caspase-9 and -3 were significantly increased in the I/R group. In addition, Dex administration further increased the expression of MCT1, whereas decreased the expressions of cytochrome c, cleaved caspase-9 and -3 in contrast to the I/R group. CONCLUSIONS: Dex elevated the expression of mitochondrial MCT1 and inhibited oxidative stress and the activation of mitochondria-dependent apoptosis in mice. This indicated that Dex attenuated myocardial I/R injury by regulating lactate signaling cascade.
Assuntos
Dexmedetomidina/farmacologia , Ácido Láctico/metabolismo , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Animais , Caspase 3/metabolismo , Caspase 9/metabolismo , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Citocromos c/metabolismo , Dexmedetomidina/uso terapêutico , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Transportadores de Ácidos Monocarboxílicos/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/citologia , Miocárdio/patologia , Estresse Oxidativo/efeitos dos fármacos , Simportadores/metabolismoRESUMO
For the first time, dissection and microscopical examination of several specimens of Chinius junlianensis Leng 1987 have revealed the antennal and palpal formulae of both males and females of this species and the true morphology of the spermathecae in the females. The latter have smooth elongated reservoirs and a very long common duct, which matches the long genital filaments of the males. There are no setae on the mesanepisternum, a feature shared with another 'primitive' genus, Warileya, and with Sergentomyia.
