Effects of L-Tetrahydropalmatine on Energy Metabolism,Endothelin-1 and NO during Acute Cerebral Ischemia-reperfusion of Rats

To investigate the effects of L-tetrahydropalmatine (L-THP) on ener-gy metabolism, endothelin-1 (ET-1 ) and NO during acute cerebral ischemia-reperfusion of rats, 24 Wistar rats were randomly divided into four groups, with 6rats in each group: sham-operation group, simple ischemia group, ischemia-reperfusion group and treatment group (L-THP group). Cerebral ATP, lactate,ET-1 and NO levels were measured in all groups. Our results showed that treat-ment with L-THP could increase cerebral ATP levels, but decrease cerebral lac-tate, ET-1 and NO concentrations during ischemia-reperfusion in the treatmentgroup. It is concluded that L-THP could improve cerebral energy metabolism and protect the injured brain tissue, the mechanism of which might be related to suppression of overproduction of ET-1 and NO.

Effects of L-Tetrahydropalmatine on Neuron Apoptosis during Acute Cerebral Ischemia-Reperfusion of Rats

To investigate the effects of L-Tetrahydropalmatine (L-THP ) on neuron apoptosis during acute cerebral ischemia-reperfusion of rats and explore the effects of heat shock protein (HSP) on neuron apoptosis, Wistar rats were randomly divided into 3 groups: normal group, ischemia- reperfusion group and treatment group. The condition of neuron apoptosis, the survival state of neuron, pathological changes under an electron microscope and the number of HSP70 positive cells were measured in all groups. Results showed that the apoptosis neuron number was increased obviously at the 24th h during reperfusion and was further increased at the 48th h, the 72th h. While the number of survival neurons was decreased gradually with the prolongation of reperfusion time. Treatment with L-THP could decrease the apoptosis neuron number but increase the survival neuron number and the HSP70 positive cell number. Our study suggested that L-THP could decrease apoptosis and necrosis of neuron, up-regulate the expression of HSP70 and protect the cerebral ischemic injury.

Effects of L-Tetrahydropalmatine on the Expressions of bcl-2 and bax in Rat after Acute Global Cerebral Ischemia and Reperfusion

To investigate the effects of L-Tetrahydropalmatine (L-THP) on the expressions of bcl-2, bax and neuronal apoptosis after cerebral ischemia and reperfusion, 60 Wistars rats were randomly divided into 3 groups: sham-operation group (group S, n = 20), ischemic-reperfusion group treated with saline (group I, n=20) and ischemia-reperfusion group treated with L-THP (group T, n=20) .The rat model of global cerebral ischemia and reperfusion was induced by Pulsinelli's four-vessel occlusion method. The expression of bcl-2 and bax mRNA was detected by in situ hybridization and reverse transcriptional polymerase chain reaction (RT-PCR). The number of apoptotic neurons was examined by terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) method. Compared with group S, the expression of bcl-2 and bax mRNA in group I was increased significantly (P<0.01), and the number of apoptotic neurons increased either (P< 0.01). After L-THP treatment, the expression of bcl-2 mRNA was up-regulated (P<0.01) and that of bax mRNA was down-regulated (P<0.01); the number of apoptotic neurons was decreased (P<0.01). Our results indicated that bcl-2 may suppress apoptosis and bax promote apoptosis after cerebral ischemia and reperfusion. L-THP could ameliorate cerebral ischemia and reperfusion damage by reducing the apoptosis through regulating bcl-2 and bax.