Role of adenosine triphosphate-sensitive potassium channel in hydrogen sulfide-induced inhibition of high glucoseinduced osteoblast damage / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The aim of this study is to identify the role of adenosine triphosphate-sensitive potassium channel (KATP) in hydrogen sulfide (H₂S)-induced inhibition of high glucose (HG)-induced osteoblast damage.</p><p><b>METHODS</b>Osteoblasts from rat mandible were cultured and identified. The osteoblasts were then treated with HG, H₂S, KATP channel opener pinacidil (Pia), and KATP channel blocker glibenclamide (Gli). Western blot method was performed to detect the expression of KATP channel protein. CCK8, reverse transcriptase polymerase chain reaction (RT-PCR) , and image analysis were used to determine the effects of H₂S-KATP on the proliferation, differentiation, and mineralization of osteoblasts.</p><p><b>RESULTS</b>The expression of KATP channel protein in osteoblasts was significantly decreased under the influence of HG. H₂S pretreatment significantly inhibited HG on KATP channel protein down-regulation. Moreover, H₂S pretreatment significantly inhibited the effect of HG on the proliferation of osteoblasts, thereby preventing HG-induced inhibition of osteoblasts differentiation and mineralization. Meanwhile, the KATP channel blocker effectively blocked the H₂S on osteoblasts and had a protective effect.</p><p><b>CONCLUSIONS</b>Through the KATP channel, H₂S inhibited osteoblasts damage induced by HG.</p>

Therapeutic effect of ATP-sensitive potassium channel opener nicorandil combined with metformin in early T2DN / 重庆医学

Objective To observe the therapeutic effect of ATP sensitive potassium channel opening agent nicorandil com‐bined with classical treatment drug metformin for treating type 2 diabetes nephropathy (T2DN ) .Methods Thirty patients with T2DN were selected and divided into the control group(14 cases) and the experimental group(16 cases) .The control group was giv‐en metformin 0 .25 g ,3 times daily for 26 consecutive weeks .The experiment group was given the same dose of metformin and nic‐orandil 5 mg ,3 times daily for 26 weeks .The fasting blood glucose ,total cholesterol ,triglycerides ,low‐density lipoprotein(LDL) , high density lipoprotein(HDL) ,blood urea nitrogen ,serum creatinine ,urine albumin ,IL‐6 and MMP‐9 levels before and after treat‐ment were measured in both groups .Results There was no statistically significant difference in fasting blood glucose level after treatment between the control group and the experimental group(P>0 .05);the LDL level after treatment in the experiment group was significantly lower than that in the control group with statistical difference(P<0 .05);blood urea nitrogen ,serum creatinine and urine albumin levels after treatment in the experimental group were significantly lower than those in the control group with sta‐tistical difference(P<0 .05);the levels of serum IL‐6 and MMP‐9 after treatment in the experiment group were significantly lower than those in the control group with statistical difference(P<0 .05) .Conclusion Metformin combined with nicorandil could delay the progression of T2DN .

Vascular Smooth Muscle Adenosine Triphosphate (ATP)-Sensitive Potassium Channel and Anesthetics / 대한마취과학회지

Adenosine triphosphate-sensitive potassium channel (KATP channel) closed by intracellular adenosine triphosphate (ATP) appears widely distributed in the vascular system. Activation of vascular smooth muscle KATP channel with hyperpolarizing agents such as lemakalim results in membrane hyperpolarization, a consequent reduction in calcium influx through voltage-dependent calcium channel, and leads to vessel relaxation. In contrast to KATP channel activation in vascular smooth muscle cell, KATP channel-induced hyperpolarization of endothelial cells results in an increase in calcium influx, which could stimulate the production of nitric oxide and prostacyclin from the endothelial cell. KATP channels response to change in the cellular metabolic status like ischemia and hypoxia, and are the target of a variety of synthetic and endogenous vasoactive substance. KATP channel openers are used as therapeutic agent for cardiovascular disease. Endogenous KATP channel-induced vasodilation is functionally important because it has been shown to modulate the pulmonary vasoconstrictor response to hypoxia and systemic hypotension in the pulmonary circulation, enhance tissue perfusion in response to hypoxia and severe hypotension in the systemic circulation. In virtro, halothane and intravenous anesthetics attenuated KATP channel agonist, lemaklim-induced vasodilation. The coronary vasodilation by volatile anesthetics such as isoflurane, enflurane and halothane was associated with activation of KATP channel in coronary artery. Further investigation is required to determine signal transduction pathway in detail stimulated by KATP channel agonist in human blood vessel and effect of anesthetics on the KATP channel-induced signal transduction, and role of KATP channel of pathophysiology of vascular disease such as hypertension, angina.

Effects of Hydrogen Sulfide on Gene Expression of Adenosine Triphosphate-Sensitive Potassium Channel of Aortic Vascular Smooth Muscle Cells in Rats / 实用儿科临床杂志

Objective To investigate the effect of hydrogen sulfide(H2S)on gene expression of adenosine triphosphate(ATP)-sensitive K+ channel(KATP)of aortic smooth muscle cells(ASMC)in rat.Methods Male Sprague-Dawley(SD)rats were used in the study.The original generation cells were obtained by modified tissue piece inoculation.The passaged cells were used.The ASMC were divided into 2 groups:H2S group of different dosages and control group.The contents of sodium hydrosulfide in the culture media of H2S group were 10-5,10-4 and 10-3 mol/L respectively,and the same volume of normal saline was added to control group.Each group was treated for 24 hours.Morphology of the cells was observed by inverted microscope and identified by immunohistochemical method employing ?-smooth muscle-actin.The expressions of SUR2B and Kir6.1 were identified by immunohistochemical SP technology.The SUR2B mRNA and Kir6.1 mRNA levels were assayed by real time fluorescence relative quantitative polymerase chain reaction.Results The passaged cells developed typical growth pattern peak and valley and the 97th percent of the cells expressed the smooth muscle specific differentiation marker ?-smooth muscle-actin.SUR2B and Kir6.1 could be detected in ASMC by immunohistochemical technology.They were both located at cytoplasmic and cytomembrane but not in at nucleus.Compared with control group,SUR2B mRNA and Kir6.1 mRNA levels in H2S groups were higher than those in control group in a dosage-dependent mode.Conclusions H2S can increased the expression KATP channel SUR2B mRNA and Kir6.1 mRNA levels of ASMC.J Appl Clin Pediatr,2009,24(1):21-23