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Uptake, incorporation and metabolism of ( 3 H)triolein in the isolated perfused rabbit heart
Author(s) -
Weis Margaret T.,
Palazzo Anthony J.,
Williams J. Lynn,
Malik Kafait U.
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/bf02538094
Subject(s) - triolein , chemistry , triglyceride , metabolism , lipoprotein lipase , lipolysis , oleic acid , glyceride , clinical chemistry , glycerol , endocrinology , medicine , biochemistry , lipase , chromatography , cholesterol , fatty acid , enzyme , biology , adipose tissue
The purpose of these experiments was to study the uptake and metabolism of exogenous triglyceride in the isolated perfused rabbit heart. When infused into the rabbit heart, [9,10‐ 3 H(N)]triolein was retained and incorporated into a lipid fraction that had the chromatographic mobility of authentic triolein. Incorporation of labeled triolein was not likely to be the result of a lipoprotein lipase‐mediated lipolysis/resynthesis cycle, since: (i) The distribution of radioactivity following administration of [ 3 H]oleic acid was markedly different from the distribution of radioactivity following the administration of [ 3 H]triolein; (ii) heparin was administered to the rabbits at the time of sacrifice; and (iii) the hearts were perfused with a protein‐free buffer for 20 min prior to the labelling period. When isoproterenol was administered to hearts labelled with [ 3 H]triolein, there was an increased output of total radioactivity, composed of labelled free fatty acids, diacylglycerol and monoacylglycerol. In these same hearts, there was an increased output of glycerol in response to isoproterenol. However, following the administration of bradykinin or angiotensin II, neither the radioactivity nor the glycerol content of the perfusate was changed. These data suggest that [ 3 H]triolein is selectively incorporated into the triglyceride pool of the isolated perfused rabbit heart. Furthermore, this [ 3 H]triolein is available to hormonally‐activated lipolytic enzymes.