Endothelium-dependent inhibition of Na(+)-K+ ATPase activity in rabbit aorta by hyperglycemia. Possible role of endothelium-derived nitric oxide.
Hyperglycemia has been shown to diminish Na(+)-K+ ATPase activity in rabbit aorta. To examine the basis for this effect, aortic rings were incubated for 3 h in Krebs-Henseleit solution containing 5.5 or 44 mM glucose, and Na(+)-K+ ATPase activity was then quantified on the basis of ouabain-sensitive (OS) 86Rb-uptake. Incubation with 44 mM glucose medium caused a 60% decrease in Na(+)-K+ ATPase activity in rings with intact endothelium (from 0.22 +/- 0.01 to 0.091 +/- 0.006 nmol/min per mg dry wt; P less than 0.01). Similar decreases (45%; P less than 0.01) in Na(+)-K+ ATPase activity were seen when rings incubated with 5.5 mM glucose were exposed to NG-monomethyl L-arginine (300 microM), an inhibitor of endothelium-derived nitric oxide (EDNO) synthesis or when the endothelium was removed (43% decrease). The decrease in Na(+)-K+ ATPase activity induced by hyperglycemia was totally reversed upon adding to the medium either L-arginine, a precursor of EDNO biosynthesis or sodium nitroprusside, which bypasses endothelium and directly activates the soluble guanylate cyclase in vascular smooth muscle. A decrease in Na(+)-K+ ATPase activity (42%; P less than 0.05), only seen in the presence of endothelium, was also observed in aortas taken directly from alloxan-induced diabetic rabbits. These studies suggest that the decrease in vascular Na(+)-K+ ATPase activity induced by hyperglycemia is related, at least in part, to a decrease in the basal release of EDNO. They also suggest that alterations in basal EDNO release and possibly Na(+)-K+ ATPase activity contribute to the impairment in vascular relaxation caused by hyperglycemia and diabetes.[1]References
- Endothelium-dependent inhibition of Na(+)-K+ ATPase activity in rabbit aorta by hyperglycemia. Possible role of endothelium-derived nitric oxide. Gupta, S., Sussman, I., McArthur, C.S., Tornheim, K., Cohen, R.A., Ruderman, N.B. J. Clin. Invest. (1992) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
