Effects of ligation and reperfusion of hepatic afferent vessels on the composition of liver cell membrane in the rat: 1H- and 31P-magnetic resonance spectroscopic analysis.
Biochemical changes that occur within hepatic tissue of the rat during ischemia and subsequent reperfusion were investigated using magnetic resonance spectroscopy of liver extracts. Hepatic ischemia was produced in the rat by a continuous clamping of the left branches of the hepatic artery and portal vein. In the reperfusion experiments, the vascular clamps were released after 30 or 120 min of ischemic periods. At the end of the periods of ischemia and/or reperfusion, the left and middle hepatic lobes were dissected and processed for subsequent 1H-MRS and 31P-MRS analyses. Phosphatidylcholine, sphingomyelin, phosphatidic acid and phosphatidylethanolamine contents all showed reduction of about 30% after 120 min of ischemia. In contrast, the content of lysophosphatidylcholine showed relatively small changes following ischemia. Ten minutes after initiation of reperfusion, further decline of the total phospholipid content resulting in as much 42% reduction was observed. Then it recovered to nearly the control level when ischemia was for 30 min, but to only 65% of the control level when ischemia was for 120 min. The cholesterol/-N-(CH3)3 ratio, generally regarded as a parameter for membrane fluidity, showed about a 40% increase when ischemia was for 120 min, a change toward decreased membrane fluidity. These results appear to reflect ischemia/reperfusion-induced changes of membrane phospholipid metabolism.
Hayakawa
Y
Y
Second Department of Physiology, School of Medicine, Iwate Medical University, Japan.
Yoshioka
Y
Y
Yasuda
N
N
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism*; D008026:Ligation; D008099:Liver / Q000098:blood supply* / Q000648:ultrastructure*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010758:Phosphorus; D011522:Protons; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion
D011522:Protons; D010758:Phosphorus