Neuroprotective effect of progesterone on focal cerebral ischemia/reperfusion injury in rats and its mechanism / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the neurological protective effects of progesterone (PROG) on focal cerebral ischemia/reperfusion injury in rats and to explore its possible mechanism.</p><p><b>METHODS</b>One handred and twenty male SD rats were divided into three groups randomly: sham-operated group, middle cerebral artery occlusion ( MCAO ) group and PROG + MCAO group( n = 40). The right temporary MCAO model was established by the line-embolism method. The PROG + MCAO group rats were according to 8 mg/kg intraperitoneal injection PROG, after that 30 min, the rats were suffered ischemia/reperfusion. After rats were suffered ischemia for 2 h and reperfusion 0, 24, 48, 72 h stress, the nervous functional defect degree were evaluated by longe scoring, and the expression of two-pore domain K channel 3 (TASK3) mRNA in brain tissue were detected by the real-time PCR.</p><p><b>RESULTS</b>PROG (8 mg/kg) could significantly reduced the nervous functional defect degree in rats after ischemia/reperfusion 24, 48, 72 h (P < 0.05). The results of real-time PCR showed that the TASK3 mRNA expression in the brain tissue at all time points significantly decreased in MCAO group compared with sham-operated group (P < 0.05). However, compared with MCAO group, the expression of TASK3 mRNA in brain tissue at all time points dramatically increased in PROG + MCAO group (P < 0.05).</p><p><b>CONCLUSION</b>PROG can improve the nervous functional defect degree after focal cerebral ischemia/reperfusion injury in rats, and the mechanism might be associated with up-regulating the expression of TASK3 mRNA in brain tissue.</p>

Effects of polydatin on learning and memory and Cdk5 kinase activity in the hippocampus of rats with chronic alcoholism / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the effects of polydatin on learning and memory and cyclin-dependent kinase 5 (Cdk5) kinase activity in the hippocampus of rats with chronic alcoholism.</p><p><b>METHODS</b>Forty rats were randomly divided into 4 groups: control group, chronic alcoholism group, low and high polydatin group. The rat chronic alcoholism model was established by ethanol 3.0 g/(kg · d) (intragastric administration). The abstinence scoring was used to evaluate the rats withdrawal symptoms; cognitive function was measured by Morris water maze experiment; Cdk5 protein expression in the hippocampus was detected by immunofluorescence; Cdk5 kinase activity in the hippocampus was detected by liquid scintillation counting method.</p><p><b>RESULTS</b>The abstinence score, escape latency, Cdk5 kinase activity in chronic alcoholism group rats were significantly higher than those of control group (P < 0.05). The abstinence score, escape latency in high polydatin group rats were significantly lower than those of chronic alcoholism group (P < 0.05); Cdk5 kinase activity in high and low polydatin group rats was significantly lower than that of chronic alcoholism group( P < 0.05); immunofluorescence showed that the Cdk5 positive cells of chronic alcoholism group were significantly increased compared with control group (P < 0.05), and the Cdk5 positive cells of polydatin groups were significantly decreased compared with chronic alcoholism group ( P < 0.05).</p><p><b>CONCLUSION</b>Polydatin-reduced the chronic alcoholism damage may interrelate with regulation of Cdk5 kinase activity.</p>

Construction of acid-sensitive potassium channel-3 eukaryotic expression plasmid and its express in SH-SY5Y cells / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To construct the acid-sensitive potassium hannel-3(TASK3) eukaryotic expression plasmid and to establish a stable SH-SY5Y cell line expressing enhanced green fluorescent protein (EGFP)-tagged TASK3.</p><p><b>METHODS</b>TASK3 coding region was subcloned into pEGFP-N1 plasmid to construct a recombinant vector alled pEGFP-TASK3. The correct recombinant expressing plasmid was transfected with X-feet transfection reagent to SH-SY5Y cells. The cell line stably expressiing EGFP tagged-TASK3 gene was established by screening with antibiotic G418 and fluorescence microscope. The expression and localization of the EGFP tagged-TASK3 fusion protein was detected by Western blot and confocal microscope. Exposure of the SH-SY5Y cell line expressing stably TASK3-eGFP fusion proteins was exposed to different pH media (7.0, 6.7, 6.4, 6.1) for 24 h, the cell viability was assessed with cell counting Kit-8 (CCK-8).</p><p><b>RESULTS</b>All the results of identification by PCR, digestion with restriction endonuclease and sequencing indicated that the recombinant eukaryotic expression plasmid pEGFP-TASK3 was constructed correctly. The stable SH-SY5Y cell line expressing EGFP tagged-TASK3 fusion protein was successfully established. Exposure of the wild type SH-SY5Y cells and the stable SH-SY5Y-GFP tag-TASK3 cell line to different pH media (7.0, 6.7, 6.4, 6.1) for 24 h, the cell viability of two group cells significantly reduced with pH declining, and the difference was statistically significant (P < 0.05). Compared with wild type SH-SY5Y cells, the cell viability of stable SH-SYSY-GFP tag-TASK3 cell line increased significantly with the same pH media, and the difference was statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>The eukaryotic expression vector pEGFP-TASK3 is successfully constructed and the cell line stably expressing TASK3-eGFP fusion is established which is important for their fundamental research and potential applications.</p>

Effects of progesterone on learning and memory and P2X7 receptor expression in the hippocampus after global cerebral ischemia/ reperfusion injury in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the effects of progesterone (PROG) on learning and memory and P2X7 receptor expression in the hippocampus after global cerebral ischemia/reperfusion (I/R) injury in rats.</p><p><b>METHODS</b>Forty-eight male SD rats were randomly divided into four groups (n = 12) that were normal group, sham-operated group, I/R group and I/R+ PROG group. The global cerebral I/R injury models were established by improved Pulsinelli's four vessel occlusion, the learning and memory were evaluated by Y-maze, the expression of P2X7 receptor protein in the hippocampus were detected by the immunofluorescence, the activity of superoxide dismutase (SOD) in the hippocampus were detected with hydroxylamine oxidation method, the content of malondialdehyde (MDA) in the hippocampus were detected with pen-thiobarbituric acid method.</p><p><b>RESULTS</b>There was no significant difference of the learning and memory and positive expression cells of P2X7 receptor protein and the activity of SOD and the content of MDA in the hippocampus between normal group and sham-operated group. Compared with sham-operated group, the learning and memory of I/R group were significantly decreased (P < 0.01), Compared with I/R group, the learning and memory of I/R + PROG group were significantly increased (P < 0.05). Compared with sham-operated group, the positive expression cells of P2X7 receptor protein in the hippocampus of I/R group was significantly increased (P < 0.01), Compared with I/R group, the positive expression cells of P2X7 receptor protein in the hippocampus of I/R + PROG group was significantly decreased (P < 0.01). Compared with sham-operated group, the activity of SOD in the hippocampus of of I/R group was significantly decreased (P < 0.01), and the content of MDA in the hippocampus of I/R group was significantly increased (P < 0.01). Compared with I/R group, the activity of SOD in the hippocampus of I/R+ PROG group was significantly increased (P < 0.05), and the content of MDA in the hippocampus of I/R + PROG group was significantly decreased (P < 0.01).</p><p><b>CONCLUSION</b>PROG could improve the learning and memory ability following global cerebral ischemia/reperfusion injury in rats, the protective mechanism might be associated with down-regulating the expression of P2X7 receptor protein and attenuating oxygen-derived free radicals in the hippocampus.</p>

Effects of taurine on the ultrastructure and P2X7 receptor expression in brain following traumatic brain injury in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the effects of taurine on the ultrastructure and P2X7 receptor protein expression in brain following traumatic brain injury (TBI) in rats.</p><p><b>METHODS</b>Forty male SD rats, were divided randomly into four groups that were sham-operated group, TBI group, TBI plus low-dose taurine group and TBI plus high-dose taurine group. The TBI model was established by Marmarou's method, the expression of P2X7 receptor protein in parietal cortex and hippocampus was detected by the immunohistochemical method, the ultrastructure of parietal cortex were observed by transmission electron microscope.</p><p><b>RESULTS</b>Compared with sham-operated group, the positive expression cells of P2X7 receptor protein in parietal cortex and hippocampus of TBI group were significantly increased (P < 0.01). Compared with TBI group, the positive expression cells of P2X7 receptor protein in parietal cortex and hippocampus of TBI plus low-dose taurine group and TBI plus high-dose taurine group were significantly decreased (P <0.01 or P <0.05). Compared with TBI plus low-dose taurine group, the positive expression cells of P2X7 receptor protein in parietal cortex and hippocampus of TBI plus high-dose taurine group were significantly decreased (P < 0.05 or P < 0.01). The pathological damage of parietal cortex in the TBI plus high-dose taurine group was obviously lightened.</p><p><b>CONCLUSION</b>Taurine exerts the neuroprotective effect on TBI in rats, the protective mechanism might be associated with down-regulating the expression of P2X7 receptor protein in parietal cortex and hippocampus.</p>

Genetic polymorphisms of the renin-angiotensin-aldosterone system in Chinese patients with end-stage renal disease secondary to IgA nephropathy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Genetic variability in the renin-angiotensin-aldosterone system may modify renal responses to injury and disease progression. The angiotensin I-converting enzyme (ACE) gene insertion/deletion (I/D), the angiotensinogen (AGT) gene, M235T, the aldosterone synthase (CYP11B2) gene, C-344T, and the angiotensin II type 1 receptor (AT1R) gene, A1166C, have been shown to be associated with IgA nephropathy (IgAN) and its progression. We determined the presence of these polymorphisms in 130 Chinese patients with IgAN, including 47 patients with end-stage renal disease (ESRD) and 120 healthy Chinese subjects, to assess their impact on the susceptibility to disease and the liability of progression to ESRD.</p><p><b>METHODS</b>Genotyping was performed with DNA isolated from peripheral leucocytes using polymerase chain reaction amplification of the polymorphic sequence, restriction enzyme digestion, and separation and identification of DNA fragments. Clinical data from renal biopsies were collected.</p><p><b>RESULTS</b>ACE, AGT, CYP and AT1R genotype distributions were similar in patients with IgAN and in controls. Comparing patients with ESRD (IgAN-ESRD) and those without ESRD (IgAN-non ESRD), there was a significant increase only in the ACE DD genotype (P < 0.05) among the four gene polymorphisms. There was significant dominance of the male (P < 0.05), more marked hypertension (P < 0.01), proteinuria (P < 0.01) and increased serum creatinine during renal biopsy (P < 0.01) in the IgAN-ESRD group.</p><p><b>CONCLUSION</b>Among the ACE, AGT, AT1R and CYP gene polymorphisms, only the DD genotype may predispose the individual to increased risk of progression to ESRD in the Chinese population.</p>

Expressions of Glucose Transporter 1,3 Gene in Hippocampus of Newborn Rats with Hypoxic-Ischemic Brain Damage by Progesterone Intervention / 实用儿科临床杂志

Objective To observe the changes of expressions of glucose transporter 1,3 gene(GLUT1 mRNA and GLUT3 mRNA) in hippocampus after hypoxic-ischemic brain damage in newborn rats and effects of progesterone on them.Methods Forty SD rats(7-day-old) were divided randomly into 4 groups:normal group,sham operation group,hypoxic-ischemic group and progesterone group.Rats were subjected to right common carotid artery ligation and exposed to 80 mL/L oxygen and 920 mL/L nitrogen gas for 2 hours to establish hypoxic-ischemic model in hypoxic-ischemic group and progesterone group.The rats in sham operation group only received right common carotid artery ligation.Progesterone(8 mg/kg) or sesame oil(of same volume) was given intraperitonealy in progesterone group or other groups 30 minutes before operation.All rats were killed 24 hours after operations.The expressions of GLUT1 mRNA and GLUT3 mRNA in hippocampus of rats in every group were assessed by adopting RT-PCR technique.Results The expressions of GLUT1 mRNA and GLUT3 mRNA in the hypoxic-ischemic group(0.674?0.083,0.785?0.093) increased markedly compared with those in sham operated group(0.374?0.061,0.519?0.060)(Pa0.05).Conclusions Progesterone maintain the energy supply of the brain by up-regulating the expression of GLUT1 mRNA and GLUT3 mRNA and accelerating the transportation of glucose into brain,which may be one of the protective mechanisms.