RESUMEN
Objective To investigate the role of HO-1 in inhibition of oxygen-glucose deprivation (OGD)-induced apoptosis in rat hippocampal neurons by sevoflurane preconditioning.Methods Hippoeanlpal neurons of newborn Wistar rats (<48 h) were cultured in vitro.Tne neurons were randomly divided into 6 groups with 108 wells in each group:control group(group C),2% sevoflurane preconditioning group (group S1),OGD group,S1 +OGD group,4% sevoflurane preconditioning+OGD group (group S2+OGD),and 4% sevoflurane preconditioning+ZnPPⅨ+OGD group(group Z).Group C received no treatment.The neurons were cultured for 24 h after 2% sevoflurane preconditioning in group S1.For OGD experiments,the neurons were placed in deoxygenated glucose-free medium and sealed under 95% N2-5% CO2 in an anaerobic chamber equilibrated to 37℃ and 100%humidity for 45 min.then OGD was terminated by replacement of the stored medium and returning the cultures to a standard incubator maintained at 37℃ in 5% C02 and the neurons were cultured for 24 h as described by Ray et al. The OGD model was established after 2% and 4% sevoflurane preconditioning in group S1 + OGD and S2 + OGD respectively. In group Z, when the neurons were preconditioned with 4% sevoflurane, ZnPPⅨ was added to the culture medium at the same time, and the other procedures were the same as those in group S2 + OGD. The neuron viability, apoptesis rate, and expression of HO-I protein and mRNA were detected at 24 h of culture. Results Compared with group C, neuron viability was significantly decreased,apoptosis rate was significantly increased, and expression of HO-1 protein and mRNA was up-regulated in group OGD, S1 + OGD, S2 + OGD and Z, expression of HO-1 protein and mRNA was up-regulated in group S1 ( P < 0.01 ), but no significant change was found in neuron viability and apoptosis rate in group S1 ( P > 0.05). Compared with group OGD, neuron viability was significantly increased, apoptosis rate was significantly decreased, and expression of HO-1 protein and mRNA was up-regulated in group S1 + OGD and S2 + OGD ( P < 0.01), but no significant change was found in the indexes mentioned above in group Z ( P > 0.05 ). Neuron viability was significantly higher, apoptosis rate lower and expression of HO-1 protein and mRNA higher in group S2 + OGD than in group S1 + OGD ( P < 0.01). Neuron viability was significantly lower, apoptosis rate higher and expression of HO-1 protein and mRNA lower in group Z than in group S2+OGD(P<0.01).Conclusion HO-1 is involved in the inhibition of OGD-indueed apoptosis in rat hippocampal neurons by sevoflurane preconditioning.
RESUMEN
Objective To study the mechanism of monophosphoryl lipid A (MPLA) protecting liver ischemia-reperfusion injury in rats, and explore the hemeoxygenase-1-carbon monoxide-cyclic guanosine monophosphate (HO-1-CO-cGMP) pathway whether involved in MPLA enhance calcitonin gene-related peptides (CGRP) releasing or not. Methods Male SD rats were randomly divided into control group, sham-operated group, hepatic ischemia-reperfusion group, MPLA low, medium and high dose groups (hepatic ischemia-reperfusion + MPLA0. 2,0. 5,1.0 mg/ kg). Hepatic isehemia-reperfusion model was constructed, followed by observation of cell ultrastructure through electron microscope. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and liver tissue levels of CO were determined. HO-1 expression in liver tissue was detected by immunohistochemic, CGRP, eGMP concentration in liver tissue was detected by RIA assay. Results Compared with hepatic isehemia-reperfusion group, the cell damage in MPLA group were relatively minor, and ALT, AST, LDH were significantly decreased (P <0.05), while HO-1, CO, cGMP, CGRP levels were signifi-cantly increased (P < 0.05). HO-1 and CO, CO and cGMP, cGMP and CGRP were obviously positive correlated (P <0.05). Conclu-sion MPLA enhanced CGRP synthesis and release through HO-1-CO-cGMP pathway in liver ischemia / reperfusion, which may be one of the mechanisms of MPLA reducing hepatic ischemia-reperfusion injury in rat.