ABSTRACT
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.
ABSTRACT
Objective To investigate the effects of Inula Britannica on myocardial caspase-3 and cytochrome c ( cyt c) following overtraining-induced acute myocardial injury in rats.Methods Forty-eight male Wistar rats weighing 200-220 g were randomly divided into 3 groups:group control (group C,n =8) ; group exhausting swim (group E,n =24) and group Inula Britannica (group IB,n =16).The animal model of overtraining-indnced acute myocardial injury was developed by exhausting swim.The animals were forced to swim until they were exhausted.The animals sank to the bottom and no righting reflex or escape response was elicited when they were taken out of water in groups E and IB.In group IB oral Inula Britannica 25 ml/kg was given 24 h and immediately before overtraining.Blood samples were taken from inferior vena cava immediately and at 6,24 h after overtraining in group E and at 6,24 h after overtraining in group IB for determination of serum cardiac troponin I (cTnI) concentration (by ELISA).The animals were sacrificed after blood sampling and myocardial specimens were obtained for microscopic examination and determination of caspase-3 and cyt c expression (by immuno-histochemistry).Results Overtraining significantly increased serum cTnI concentration and up-regulated myocardial caspase-3 and cyt c expression in group E as compared with group C.Oral Inula Britannica significantly attenuated overtraining-induced increase in serum cTnI concentration and myocardial caspase-3 and cyt c expression in group IB as compared with group E.Conclusion Inula Britannica can reduce overtraining-induced acute myocardial injury by down-regulating caspase-3 and cyt c expression.
ABSTRACT
Objective To evaluate the role of P2X3 receptors in dorsal root ganglion in development of incisional pain in rats.Methods Twenty-four healthy male SD rats weighing 200-220 g were randomly divided into 3 groups(n = 8 each): control group(group C),incisional pain(group IP)and P2X3 receptor antagonist + IP group(group A).In group IP and A,a 1 cm longitudinal incision was made in the plantar surface of left hindpaw according to the method described by Brennan et al.in isoflurane-anesthetized rats.P2X3 receptor antagonist TNP-ATP 200 nmol was injected into the plantar surface of left hindpaw 30 min after plantar incision was made in group A,while equal volume of normal saline was given instead of TNP-ATP in group C and IP.The behavior of the hindpaw of the rats were assessed using cumulative pain score within 1 h after injection.The animals were sacri ficed 2 h after injection and the dorsal root ganglion was removed for determination of P2X3 receptor expression and intracellular Ca2+ concentrations.ResultsThe cumulative pain scores,P2X3 receptor expression and Ca2 + concentrations were significantly higher in group IP and A than in group C(P ＜ 0.05).The cumulative pain scores,P2X3 receptor expression and Ca2+ concentrations were significantly lower in group A than in group IP(P ＜0.05).Conclusion P2X3 receptors in dorsal root ganglion is involved in the development of incisional pain through increasing intracellular Ca2+ concentrations in rats.