Linked Life Data

9507201

Source:http://linkedlifedata.com/resource/pubmed/id/9507201

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-4-21
pubmed:abstractText
Diverse physical and chemical stimuli can activate sphingomyelinases (SMases), resulting in sphingomyelin (SM) hydrolysis with ceramide release. Since ceramide can profoundly impact a host of homeostatic mechanisms, the concept of a "SM (or SMase) signaling pathway" has emerged. We recently documented that ceramide levels fall abruptly during renal ischemia, and then rebound to twice normal values during early reperfusion (30 to 90 min) Therefore, the present study assessed whether these ceramide changes are paralleled, and hence potentially mediated, by comparable changes in SMase activity. Mice were subjected to 45 minutes of renal ischemia +/- 30 minutes, 90 minutes, or 24 hours of reperfusion. Renal cortices (or isolated proximal tubules) were then assayed for SMase activity (acidic, neutral forms). To characterize whether early post-ischemic ceramide increments are a relatively persistent event, ceramide was assayed following a 24-hour reperfusion period. Finally, to assess whether the observed perturbations were unique to post-ischemic injury, SMase and ceramide were quantified in the setting of glycerol-induced myohemoglobinuria and anti-glomerular basement membrane (alpha GBM) antibody-induced acute renal failure (ARF). Ischemia induced abrupt declines (approximately 50%) in both acidic and neutral SMase activities, and these persisted in an unremitting fashion throughout 24 hours of reperfusion. Nevertheless, increased ceramide expression (2x normal) resulted. Myohemoglobinuria also suppressed acidic/neutral SMases, and again, "paradoxical" ceramide increments were observed. Finally, alpha GBM nephritis increased ceramide levels, but in this instance, a correlate was increased SMase activity. These results suggest that: (1) ceramide is an acute renal "stress rectant" increasing in response to diverse renal insults; (2) this response may occur independently of the classic SM pathway, since the ceramide increments can seemingly be dissociated from increased SMase activity; and (3) given the well documented impact of ceramide and the SM(ase) pathway on apoptosis, cell proliferation, differentiation, and tissue inflammation, the present results have potentially broad ranging implications for the induction and evolution of diverse forms of ARF.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0085-2538
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
573-82
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Altered sphingomyelinase and ceramide expression in the setting of ischemic and nephrotoxic acute renal failure.
pubmed:affiliation
Department of Medicine, University of Washington, Seattle, USA. dzager@fhcrc.org
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't