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Mechanism of lysophosphatidylcholine accumulation in the ischemic canine heart
Author(s) -
Mock Thomas,
Man Ricky Y. K.
Publication year - 1990
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02537977
Subject(s) - lysophosphatidylcholine , lysophospholipase , microsome , ischemia , medicine , chemistry , phospholipase , phospholipase a2 , enzyme , clinical chemistry , endocrinology , biochemistry , biology , phosphatidylcholine , phospholipid , membrane
The metabolism of lysophosphatidylcholine (LPC) in non‐ischemic and ischemic canine heart was investigated by in vitro enzyme analysis. Selected subcellular fractions were assayed for the LPC‐producing enzyme phospholipase A and the LPC‐eliminating enzymes LPC:acyl‐CoA acyltransferase, LPC:LPC transacylase and lysophospholipase. The canine heart was found to contain all enzymes differing, however, in subcellular distribution and specific activity. Phospholipase A activity did not change significantly in any of the fractions prepared from the ischemic tissue of hearts rendered ischemic for 1, 3 or 5 hr when compared to non‐ischemic tissue. Changes in the activity of the microsomal LPC:acyl‐CoA acyltransferase over the course of 5 hr of ischemia were observed. Significant decreases in the activity of the cytosolic and microsomal lysophospholipases were detected especially after 3 and 5 hr of ischemia. Similarly, a decrease in the activity of the microsomal LPC:LPC transacylase was noted after 3 and 5 hr of ischemia. Our results suggest that impaired catabolism of LPC rather than an enhanced production of LPC is the principal mechanism for the increase in LPC levels in the ischemic canine heart.