The online version of this article (doi:10.1186/1475-2840-11-8) contains supplementary material, which is available to authorized users.
The authors declare that they have no competing interests.
JTC, LJC and KCC carried out the molecular studies and drafted the manuscript. YZC and YXL were involved in the interpretation of the results. ZCC and JTC conceived the study and participated in its design, interpretation and coordination, and drafted and approved the manuscript. All authors have read and approved the final manuscript. Also, all authors contributed significantly to and are in agreement with the content of the manuscript.
An impairment of cardiovascular function in streptozotocin (STZ)-diabetic rats has been mentioned within 5 days-to-3 months of induction. ATP-sensitive potassium (KATP) channels are expressed on cardiac sarcolemmal membranes. It is highly responsive to metabolic fluctuations and can have effects on cardiac contractility. The present study attempted to clarify the changes of cardiac KATP channels in diabetic disorders.
Streptozotocin-induced diabetic rats and neonatal rat cardiomyocytes treated with a high concentration of glucose (a D-glucose concentration of 30 mM was used and cells were cultured for 24 hr) were used to examine the effect of hyperglycemia on cardiac function and the expression of KATP channels. KATP channels expression was found to be linked to cardiac tonic dysfunction, and we evaluated the expression levels of KATP channels by Western blot and Northern blot analysis.
The result shows diazoxide produced a marked reduction of heart rate in control group. Furthermore, the methods of Northern blotting and Western blotting were employed to identify the gene expression of KATP channel. Two subunits of cardiac KATP channel (SUR2A and kir 6.2) were purchased as indicators and showed significantly decreased in both diabetic rats and high glucose treated rat cardiac myocytes. Correction of hyperglycemia by insulin or phlorizin restored the gene expression of cardiac KATP in these diabetic rats.
Both mRNA and protein expression of cardiac KATP channels are decreased in diabetic rats induced by STZ for 8 weeks. This phenomenon leads to result in desensitization of some KATP channel drugs.
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Santos RM, Barbosa RM, Antunes CM, Silva AM, Salgado AP, Abrunhosa AJ, Pereira FC, Seica RM, Rosario LM: Bursting electrical activity generated in the presence of KATP channel blockers. Pharmacology, sensitivity to intracellular pH and modulation by glucose metabolism. Adv Exp Med Biol. 1997, 426: 33-41. CrossRefPubMed
Moritz W, Leech CA, Ferrer J, Habener JF: Regulated expression of adenosine triphosphate-sensitive potassium channel subunits in pancreatic beta-cells. Endocrinology. 2001, 142: 129-138. 10.1210/en.142.1.129. PubMed
Iglesias-De La Cruz MC, Ruiz-Torres P, Alcami J, Diez-Marques L, Ortega-Velazquez R, Chen S, Rodriguez-Puyol M, Ziyadeh FN, Rodriguez-Puyol D: Hydrogen peroxide increases extracellular matrix mRNA through TGF-beta in human mesangial cells. Kidney Int. 2001, 59: 87-95. 10.1046/j.1523-1755.2001.00469.x. CrossRefPubMed
Gando S, Hattori Y, Akaishi Y, Nishihira J, Kanno M: Impaired contractile response to beta adrenoceptor stimulation in diabetic rat hearts: alterations in beta adrenoceptors-G protein-adenylate cyclase system and phospholamban phosphorylation. J Pharmacol Exp Ther. 1997, 282: 475-484. PubMed
Koya D: [Molecular understanding of adverse effects of hyperglycemia in diabetic nephropathy]. Nippon Jinzo Gakkai Shi. 2007, 49: 470-473. PubMed
Mentink CJ, Kilhovd BK, Rondas-Colbers GJ, Torjesen PA, Wolffenbuttel BH: Time course of specific AGEs during optimised glycaemic control in type 2 diabetes. Neth J Med. 2006, 64: 10-16. PubMed
- Increase of ATP-sensitive potassium (KATP) channels in the heart of type-1 diabetic rats
Yin- Xiao Li
Juei- Tang Cheng
- BioMed Central
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