RESUMEN
Objective 17β-estradiol is known to have a neuroprotective effect.The aim of this study was to investigate the effects of 17β-estradiol on propofol-induced neuroapoptosis in primarily cultured cortical neurons. Methods Rat cortical neurons were primarily cultured for 7 days and randomly divided into groups A ( vehicle control) , B, and C, treated with equal volume of 20%intralipid, 500 μmol/L propofol, and 500 μmol/L propofol +0.1 μmol/L 17β-estradiol, respectively.At 12 hours after treatment, the morphology of the neurons was observed under the microscope, their survival rate calculated by MTT, their apoptosis was deter-mined by FCM assay, and their mitochondrial membrane potential measured by fluorescent dye rhodamine 123. Results Compared with group A, group B showed a significantly reduced number of neurons, lack of 3-dimensional appearance, unclear contour, and fractured neuron axons, but a remarkable improvement was observed in the propofol-induced morphological damage in group C.The survival rate of the neurons and the mitochondrial membrane potential were markedly decreased in group B ([52.3 ±5.2]% and [59.1 ± 5.3]%) as compared with groups A ( [99.9 ±3.6]%and [99.6 ± 5.8]%) and C ([90.1 ±7.2]%and [89.2 ±7.1]%) (both P<0.01 ) , while the rate of neuroapoptosis significantly increased in group B ([43.4 ±4.6]%) in comparison with A ([3.1 ±0.2]%) and C ([22.3 ±3.2]%) (both P<0.01). Conclusion 17β-es-tradiol can protect against propofol-induced apoptosis of primarily cul-tured neurons by inhibiting the reduction of their mitochondrial membrane potential.
RESUMEN
Objective To investigate the mechanisms of the protective effects of dexmedetomidine against the propofol-induced neuroapoptosis in primary cultured cortical neurons.Methods The neurons were cultured 7days and then divided into four groups: vehicle-control group (treated with equal volume of intralipid), propofoltreated group (treated with 500 μmol/L propofol), propofol plus dexmedetomidine treated group (treated with 500 μmol/L propofol and 0.1 μmol/L dexmedetomidine), and LY294002 pretreated group (treated with 500 μmol/L propofol ,0.1 μ mol/L dexmedetomidine and 10 μmol/L LY294002).12 hours after different treatments, neuron viability was measured by MTT assay,neuroapoptosis was detected by Hoechst33258 staining, and the levels of pAkt and Bcl-2 protein were detected by Western blot.Results Compared with the vehicle-reduced group,propofol reduced neuron viability greatly((53.4±4.2)％ vs (99.9±6.3)％;P＜0.01), but increased neuroapoptosis greatly((44.6±4.3)％ vs (5.8±0.4)％;P＜0.01).The levels of pAkt((0.41±0.03) vs (0.86±0.07))and Bcl-2 ((0.15±0.02) vs (0.72±0.03)) were decreased greatly (both P＜0.01).Compared with propofol treatment group, the neuron viability of propofol plus dexmedetomidine group were increased greatly((86.4±5.3) ％ , P＜0.01) ,the neu roapoptosis was decreased greatly ((23.1 ± 3.5) ％, P＜ 0.01), and the levels of pA kt (0.8 ± 0.03) and Bc1-2 (0.52 ±0.05) were increased greatly (both P＜0.01).Compared with propofol plus dexmedetomidine treated group,LY294002 inhibited the protective effects of dexmedetomidine, decreased neuron viability greatly ((64.3±5.1) ％ ,P＜0.01), increased the number of apoptotic neurons((38.8±4.9) ％, P＜0.01), and reduced the levels of pAkt (0.52±0.04) and Bcl-2(0.31±0.02) significantly (P＜0.01).Conclusion Dexmedetomidine exerts the neuroprotective effects against propofol-induced neuroapoptosis by activating the PI3K-Akt-Bcl-2 signalling pathway.