Equol protects PC12 neuronal cells against hypoxia/reoxygenation injury in vitro by reducing reactive oxygen species production / 南方医科大学学报

<p><b>OBJECTIVE</b>Both of gp91(phox) (an isoform of nicotinamide adenine dinucleotide phosphate-reduced oxidases) and Src (a non-receptor protein tyrosine kinase) play a prominent role in mediating hypoxia/reoxygenation injury of neurons. The present study was designed to investigate the neuroprotective effect of equol, a predominant active metabolite of daidzein, against hypoxia/reoxygenation injury in rat pheochromocytoma cell line (PC12) and explore the underlying mechanisms.</p><p><b>METHODS</b>PC12 cells exposed to hypoxia/reoxygenation injury were examined for reactive oxygen species (ROS) using dihydroethidium and 2', 7'-dichlorofluorescein diacetate and analyzed for changes in lactate dehydrogenase (LDH) activity and malondialdehyde (MDA) content. The expression levels of gp91(phox) and phosphorylated Src-Tyr416 (p-Src) were measured using Western blotting.</p><p><b>RESULTS</b>Equol dose-dependently restored the cell viability and decreased LDH activity and MDA content in culture medium of PC12 cells exposed to hypoxia/reoxygenation. Pretreatment of the cells with 10(-5) and 10(-6) mol/L equol inhibited hypoxia/reoxygenation-induced increase of ROS. PC12 cells treated with equol prior to hypoxia/reoxygenation injury showed significant enhancement of the protein levels of gp91(phox) and p-Src.</p><p><b>CONCLUSION</b>Equol confers neuroprotection against hypoxia/reoxygenation injury in PC12 cells by inhibiting the generation of ROS very likely as a result of down-regulation of gp91(phox) and inhibition of Src phosphorylation.</p>

Ca(2+)-activated K(+) channel switching in smooth muscle participates in atherosclerosis development in diabetic rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in aorta morphology and Ca(2+)-activated K(+) (KCa) channel expression in the diabetic rats.</p><p><b>METHODS</b>A diabetic rat model was established by a single intraperitoneal injection of streptozotocin (30 mg/kg) after a modified high fat and glucose diet for 8 weeks. Pathological changes in the aorta were observed with HE staining, elastic fiber staining, Masson's trichrome staining and immunohistochemistry. Both the mRNA and protein levels of KCa channels in the aorta were measured by RT-PCR and Western blotting.</p><p><b>RESULTS</b>Early atherosclerotic changes were observed in the aorta wall of the diabetic rats. The mRNA and protein levels of KCa1.1 channel α- and β-subunits were significantly decreased, while the expression of KCa3.1 channels was obviously enhanced in the middle layer of the aorta in the diabetic rats.</p><p><b>CONCLUSION</b>KCa channel switching in smooth muscles may play a role in the development of atherosclerosis in diabetic rats.</p>

Oxidative stress impairs IKCa- and SKCa-mediated vasodilatation in mesenteric arteries from diabetic rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of oxidative stress in impaired intermediate-conductance Ca(2+)-activated potassium channels (IKCa)- and small-conductance Ca(2+)-activated potassium channels (SKCa)-mediated relaxation in diabetic resistance arteries.</p><p><b>METHODS</b>Rat diabetic model was induced by a high fat and high glucose diet and streptozotocin (STZ) injection. Endothelial function of mesenteric arteries was assessed with the use of wire myography. The expression levels of IKCa and SKCa in cultured human umbilical vein endothelial cells (HUVECs) treated with H2O2 and/or antioxidant alpha lipoic acid (ALA) were measured using Western blotting.</p><p><b>RESULTS</b>IKCa- and SKCa-mediated vasodilatation in response to acetylcholine was impaired in the third-order mesenteric arterioles of diabetic rats. In cultured HUVECs, H2O2 significantly decreased the protein expression of IKCa and SKCa. ALA alleviated the impairment of both vasodilatation function of the mesenteric arterioles ex vivo and enhanced the expression of IKCa and SKCa challenged with H2O2 in cultured HUVECs.</p><p><b>CONCLUSION</b>Our data demonstrated for the first time that impaired IKCa- and SKCa-mediated vasodilatation in diabetes was induced, at least in part, by oxidative stress via down-regulation of IKCa and SKCa channels.</p>

Effects of metabolic memory mediated by high glucose on functional injury of human umbilical vein endothelial cells / 中华内分泌代谢杂志

Cultured primary human umbilical vein endothelial cells (HUVECs) were divided into 4 groups:normal control( NG ),persistent high glucose ( HG ),hyperglycemia group ( TG ),and mannitol control ( MA )groups.After 1,4,and 7 days of culture,cells were collected.Cell proliferation,cell apoptosis,ROS,SOD,MDA,and NO level,eNOS mRNA and protein level were measured.Endothelial cell proliferation was inhibited in HG,TG,and MA groups compared with NG group.Hyperglycemia memory induced apoptosis of endothelial cells,increased ROS and MDA generation,and down-regulated intracellular SOD level,findings similar to those in HG group.After 24 h of culturing,eNOS expression and NO generation in both HG and TG groups were higher than those in NG group.However,after 7 days of culturing,eNOS expression and NO generation in both HG and TG groups were lower than those in NG group.These results suggest that in hyperglycemia memory cell model,transient hyperglysemia may lead to persistent imbalance in oxidative stress and reduce endothelium-derived relaxing factor NO level,indicating that hyperglycemia memory may play an important role in persistent vascular endothelial cell injury.

Variation of serum monocyte chemoattractant protein-1 in patients with diabetes and metabolic syndrome / 华中科技大学学报（医学）（英德文版）

This study investigated the variation of serum monocyte chemoattractant protein-1 (MCP-1) in patients with both diabetes mellitus (DM) and metabolic syndrome (MS). Based on the International Diabetes Federation (IDF) diagnostic criteria, 93 patients enrolled in this study were divided into four groups: normal control (NC), simple DM, simple MS, and DM plus MS (DM-MS) groups. The main measures included height, weight, waist circumference (WC), hip circumference, blood pressure, fasting blood glucose, insulin resistance index (HOMA-IR), serum triglyceride (TG), HDL-ch, LDL-ch, and MCP-1. The results showed that the serum levels of MCP-1 in the DM-MS group were significantly increased as compared with those in the DM and MS groups (P<0.05), and the increase in the MCP-1 level in the DM group was much higher than in the MS group (P<0.05). The DM-MS group had the highest HOMA-IR levels, followed by MS, DM and NC groups (P<0.05). Correlation tests showed that the association of MCP-1 with age, HDL-ch, or LDL-ch was insignificant, whereas that of MCP-1 with body mass index (BMI), waist hip rate (WHR), WC, systolic blood pressure (SBP), diastolic blood pressure (DBP), TG, and HOMA-IR was significantly positive. It was concluded that circulating MCP-1 was substantially increased in patients with both DM and MS as compared with that in the patients with DM or MS alone, and the central obese state may contribute to a more vicious proinflammatory condition and insulin resistance in patients with diabetes.

Changes of serum gastrin and CCK2R expression of visceral adipocytes in catch-up rats / 中华内分泌代谢杂志

Wistar rats(n=24) were divided into normal control group(NC), food restriction group(FR), and catch-up group(RN). Serum glucose,lipids, gastrin, the ratio of visceral fat to body fat, adipocyte CCK2R mRNA and protein levels were determined. Compared with NC group, FR rats had lower serum gastrin and visceral fat formation. The adipocyte CCK2R mRNA and protein levels of FR rats were lower than those of NC rats. Serum gastrin level of RN rats was higher than those of FR and NC rats(P＜0.05). The ratio of visceral fat to body fat in RN rats increased compared with FR rats and was close to that of NC rats. The adipocyte CCK2R mRNA and protein levels of RN rats were higher than those of FR and NC rats. Gastrin and its receptor pathway possibly play a role in the mechanism of visceral fat accumulation in catch-up rats.

Effects of adult catch-up growth on insulin sensitivity and stress in rats / 中华内分泌代谢杂志

ObjectiveTo investigate the effects of adult catch-up growth on insulin sensitivity and stress in rats, as well as the probable mechanism of insulin resistance. MethodsMale Sprague-Dawley rats were divided into 6 groups:caloric restriction group ( R4, caloric restriction for 4 weeks) and normal controls for 4 weeks ( NC4 ) ; catchup growth group refed with normal chow( RN4, refeeding for 4 weeks after caloric restriction for 4 weeks), catch-up growth group refed with high-fat diet( RH4, refeeding for 4 weeks after caloric restriction for 4 weeks ), normal chow (NC8) or high-fat diet( HF8 ) controls for 8 weeks. The animal model of catch-up growth was devoloped by way of refeeding after caloric restriction as scheduled. The glucose infusion rate( GIR ), 2-deoxyglucose uptake and insulinsitmulated insulin signaling in skeletal muscle during hyperinsulinemic-euglycemic clamp, plasma corticosterone, and 11β-hydroxysteroid dehydrogenase type 1 ( 11β-HSD1 ) mRNA expression level in skeletal muscle were determined.ResultsAfter caloric restriction for 4 weeks, plasma corticosterone and 1 1 β-HSD1 mRNA expression in skeletal muscle were significantly higher in R4 group compared with NC4 group( both P＜0. 05 ), but there were no differences in 2-deoxyglucose uptake and Ser473 phosphorylation of Akt in skeletal muscle between two groups. The plasma corticosterone and 11β-HSD1 mRNA expression in skeletal muscle in RN4 group were significantly higher than those in NC8 group, and were higher in RH4 group than those in NC8 and HF8 groups; while the 2-deoxyglucose uptake and insulin-stimulated Ser473 phosphorylation of Akt in skeletal muscle during the clamp in RN4 were remarkably lower than those in NC8 group, and were lower in RH4 than those in NC8, HF8, and RN4 groups (all P ＜ 0. 05 ).ConctusionsCatch-up growth rats refed with normal chow or high-fat diet are characterized by significant insulin resistance and stress in the whole body and skeletal muscle. These changes are more evident in catch-up growth rats refed with high-fat diet. The interaction of increased stress and diet might be of utmost importance in the etiology of insulin resistance in catch-up growth animals.

Dynamic changes of biological characteristics in modified catch-up growth rat model / 中华内分泌代谢杂志

dation, transiently inercasod food efficiency,and a faster growth rate of visceral adipose tissue versus body weight after nutritional rehabilitation. These findings are consistent with the characteristics of human catch-up growth.

Efficacy and Safety of Risedronate Sodium in Treatment of Postmenopausal Osteoporosis / 华中科技大学学报（医学）（英德文版）

To evaluate the efficacy and safety of risedronate sodium in treatment of postmenopausal osteoporosis, one-year randomized, double blind clinical trial was performed among 54 women with postmenopausal osteoporosis. The changes were compared in bone mineral density (BMD), bone metabolism markers and adverse events after 12 months oral administration of risedronate sodium.BMD was measured by dual energy X-ray absorptionmetry (DEXA) and bone turnover marker was detected. The results showed that there was a significant increase in BMD of the lumbar spine (3.29 % ± 1.18 %, 4. 51% ±1.64 % respectively) after 6 and 12 months in the risedronate treatment group versus placebo control group (-0.62 % ±0.24 %, 0.48 % ±0.18 % respectively).Bone turnover was decreased to a stable nadir over 6 and 12 months for resorption markers [N-Telopeptide (NTx), P＜0. 05] and over 12 months for formation marker (ALP, P＜0.05; BGP, P＜0.05). The safety profile of risedronate sodium was similar to that of placebo. There were no trends toward increased frequency of any adverse experience except for gastrointestinal symptoms (7.1%), rash (7.1%) and hematuria (3.6 %), which were usually mild, transient, and resolved with continued treatment. It was concluded that risedronate was an efficacious and safe drug in treatment of postmenopausal osteoporosis.

Efficacy and safety of risedronate sodium in treatment of postmenopausal osteoporosis / 华中科技大学学报（医学）（英德文版）

To evaluate the efficacy and safety of risedronate sodium in treatment of postmenopausal osteoporosis, one-year randomized, double blind clinical trial was performed among 54 women with postmenopausal osteoporosis. The changes were compared in bone mineral density (BMD), bone metabolism markers and adverse events after 12 months oral administration of risedronate sodium. BMD was measured by dual energy X-ray absorptionmetry (DEXA) and bone turnover marker was detected. The results showed that there was a significant increase in BMD of the lumbar spine (3.29% +/- 1.18%, 4.51% +/- 1.64% respectively) after 6 and 12 months in the risedronate treatment group versus placebo control group (-0.62% +/- 0.24%, 0.48% +/- 0.18% respectively). Bone turnover was decreased to a stable nadir over 6 and 12 months for resorption markers [N-Telopeptide (NTx), P < 0.05] and over 12 months for formation marker (ALP, P < 0.05; BGP, P < 0.05). The safety profile of risedronate sodium was similar to that of placebo. There were no trends toward increased frequency of any adverse experience except for gastrointestinal symptoms (7.1%), rash (7.1%) and hematuria (3.6%), which were usually mild, transient, and resolved with continued treatment. It was concluded that risedronate was an efficacious and safe drug in treatment of postmenopausal osteoporosis.

Regulation of insulin secretion and expression of SUR1 gene by chronic exposure to free fatty acids in rat pancreatic beta cells / 华中科技大学学报（医学）（英德文版）

To study the effects of free fatty acids on insulin secretion and expression of SUR1 gene in rat pancreatic B cells in vitro, and to explore the molecular mechanisms in lipotoxicity inducing insulin secretion dysfunction, pancreatic islet cells were isolated and digested from male SD rats. Purified islets were incubated with either 0.25 mmol/L palmitate or 0.125 mmol/L oleate for 48 h in vitro. Then islets were stimulated with either 5.6 mmol/L or 16.7 mmol/L glucose for 1 h. Insulin release was measured by using radioimmunoassay, and the expression of SUR1 gene mRNA was quantified by reserve transcription-polymerase chain reaction (RT-PCR). The islets exposed to both palmitate and oleate for 48 h showed an increased basal and a decreased glucose-indused insulin release as compared with control islets. Palmitate increased basal insulin secretion by 110% (P< 0.01), decreased glucose stimulated insulin secretion by 43% (P<0.01); while oleate increased basal insulin secretion by 80% (P<0.01) and decreased glucose stimulated insulin secretion by 32 % (P<0.05). RT-PCR showed that oleate significantly suppressed SUR1 gene expression by 64 % (P<0.01) as compared with the control group, while palmitate group manifested a light decrease of 15% (P>0.05) of SUR1 gene expression. Our results suggested that chronic exposure to free fatty acids of pancreatic beta cells inhibited glucose stimulated insulin secretion. Regulation of SUR1 gene expression may be involved in such effects, which may also be one of the molecular mechanisms in lipotoxocity inducing beta cells secretion dysfunction.

Regulation of leptin on insulin secretion and sulfonulurea receptor 1 transcription level in isolated rats pancreatic islets / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the regulation of leptin on insulin secretion and expression of ATP-sensitive potassium channel subunit sulfonulurea receptor 1 (SUR1) mRNA, and to determine whether the effects of leptin are mediated through known intracellular signaling transduction.</p><p><b>METHODS</b>Pancreatic islets were isolated by the collagenase method from male SD rats. The purified islets were incubated with different concentrations of leptin for 2 h in the presence of different concentrations of glucose. Insulin release was measured using radioimmunoassay. Expression of SUR1 mRNA was detected by RT-PCR.</p><p><b>RESULTS</b>In the presence of leptin 2 nmol/L, insulin release was significantly inhibited at either 11.1 or 16.7 mmol/L glucose concentration (both P < 0.05), but insulin release was not altered at glucose of 5.6 mmol/L physiological concentration. The dose-response experiment showed that the maximal effect of leptin on insulin secretion achieved at 2 nmol/L. Exposure of islets to 2 nmol/L leptin induced a significant increase of SUR1 transcription levels by 71% (P < 0.01) at 11.1 mmol/L glucose and by 56% (P < 0.05) at 16.7 mmol/L glucose concentration. Selective phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor wortmannin significantly prevented the leptin effect on insulin secretion and SUR1 mRNA expression.</p><p><b>CONCLUSIONS</b>Regulatory effects of leptin on insulin secretion could be biphasic at different concentrations of glucose and leptin. The stimulatory regulation of SUR1 transcription levels may be mediated through activation of PI 3-kinase pathway, which may be a possible mechanism of leptin in regulating insulin secretion.</p>

Study on Decreasing Effects of Polydatin on Blood Viscosity in the Rat Model of Acute Blood Stasis / 中国药房

OBJECTIVE:To observe the decreasing effects of Polydatin on blood viscosity and microcirculation in the rat model of acute blood stasis.METHODS:The rat model of acute blood stasis was established with high dose of adrenaline sub?cutaneous injection in combination with ice-water socking.The parameters such as whole blood viscosity?bat low and high shear rates,hemotocrit,platelet adhesiveness testPAdT,fibrinogenFIB,plasma viscosity?petc.were used.RESULTS:The results showed that Polydatin reduced FIB,PAdT in rat model remarkably.It obviously caused a reduction of?p,which induced decrease of?b.The effect was more significant than any other factors in reducing blood viscosity and improving mi?crocirculation.CONCLUSION:Polydatin is helpful to reduce blood viscosity and improve microcirculation.The data provided would be useful for rational use of drug.

Chromatographic study on bio-affinity of drugs to rat aorta tissue and cultured smooth muscle cell in cell membrane / 西安交通大学学报(医学版)

Objective To compare the specificities of the cell membrane stationary phases(CMSP) with cell membrane chromatography(CMC).Methods Cell chromatographic columns were constructed for both rat aorta tissue cells and cultured rat aorta smooth muscle cells.Then the chromatographic affinities of ten ligands of ?-adrenergic receptor(?-AR) with both said chromatographic columns were investigated.Capacity factors(k'),as a chromatographic parameter,were calculated.Results The correlation analysis showed a positive correlation between the rat aorta tissue CMSP and the cultured rat aorta smooth muscle cell CMSP,with correlation factor of r=0.923,P

Protective effects of divitamins notonginseng and cinnarizine capsule against acute cerebral ischemia / 西安交通大学学报(医学版)

Objective To investigate the effects of divitamins notonginseng and cinnarizine capsule(DNCC) on acute cerebral ischemia.Methods ICR mice were administered three doses of DNCC(420,210,and 105mg/kg;ig.) for ten days,then the gasping time after decapitation was recorded.After three doses of DNCC(292,146,and 73mg/kg;ig.) were given respectively for ten days in rats,the effects of DNCC on the infarct size,histological changes and neurological function scores caused by focal cerebral ischemia which was induced by middle cerebral artery occlusion were investigated.Results DNCC prolonged the gasping time of mice after decapitation and improved the neurological function scores,cerebral ischemia injury and decreased the infarct size in rats.Conclusion DNCC has a protective effect against acute cerebral ischemia.