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This Article Full Text Full Text (PDF) All Versions of this Article: 295/4/F912    most recent 00040.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Prathapasinghe, G. A. Articles by O, K. Search for Related Content PubMed PubMed Citation Articles by Prathapasinghe, G. A. Articles by O, K.

Inhibition of cystathionine-β-synthase activity during renal ischemia-reperfusion: role of pH and nitric oxide

¹Department of Animal Science and ²Department of Physiology, University of Manitoba; ³Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Research Centre, Winnipeg; and ⁴Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada

Submitted 23 January 2008 ; accepted in final form 4 August 2008

Our recent study (Prathapasinghe GA, Siow YL, O K. Am J Physiol Renal Physiol 292: F1354–F1363, 2007) indicates that homocysteine (Hcy) plays a detrimental role in ischemia-reperfusion-induced renal injury. Elevation of renal Hcy concentration during ischemia-reperfusion is attributed to reduced activity of cystathionine-β-synthase (CBS) that catalyzes the rate-limiting step in the transsulfuration pathway for the metabolism of the majority of Hcy in the kidney. However, the mechanisms of impaired CBS activity in the kidney are unknown. The aim of this study was to investigate the effects of pH and nitric oxide (NO) on the CBS activity in the kidney during ischemia-reperfusion. The left kidney of a Sprague-Dawley rat was subjected to ischemia-reperfusion. The CBS activity was significantly reduced in kidneys subjected to ischemia alone (15–60 min) or subjected to ischemia followed by reperfusion for 1–24 h. The pH was markedly reduced in kidneys upon ischemia. Injection of alkaline solution into the kidney partially restored the CBS activity during ischemia. Further analysis revealed that reduction of CBS activity during reperfusion was accompanied by an elevation of NO metabolites (nitrate and nitrite) in the kidney tissue. Injection of a NO scavenger, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), restored the CBS activity in the kidneys subjected to ischemia-reperfusion. Treatment with PTIO could abolish ischemia-reperfusion-induced lipid peroxidation and prevent cell death in the kidney. These results suggested that metabolic acidosis during ischemia and accumulation of NO metabolites during reperfusion contributed, in part, to reduced CBS activity leading to an elevation of renal Hcy levels, which in turn, played a detrimental role in the kidney.

homocysteine; oxidative stress; apoptosis

This article has been cited by other articles:

				Z. Xu, G. Prathapasinghe, N. Wu, S.-Y. Hwang, Y. L. Siow, and K. O Ischemia-reperfusion reduces cystathionine-{beta}-synthase-mediated hydrogen sulfide generation in the kidney Am J Physiol Renal Physiol, July 1, 2009; 297(1): F27 - F35. [Abstract] [Full Text] [PDF]