Release of fatty acid-binding protein and long chain fatty acids from isolated rat heart after ischemia and subsequent calcium paradox.
To obtain insight into the relation between the release of heart-type fatty acid-binding protein (H-FABPc) and of long-chain fatty acids (FA) from injured cardiac tissue, rat hearts were Langendorff perfused according to the following scheme: 30 min normoxia, 60 min ischemia, 30 min reperfusion, 10 min Ca2+ free perfusion and finally 10 min Ca2+ repletion. During this protocol right ventricular (Qrv) and interstitial effluent samples (Qi) were collected at regular intervals. During reperfusion a total of 0.8 +/- 0.1 nmol H-FABPc but no FA were detected in the effluents. However, during Ca2+ readmission, 45 +/- 4 nmol H-FABPc (80-90% of total tissue content) was released with an initial (first 3 min) simultaneous release of FA (FA/H-FABPc ratio 0.90 +/- 0.07 mol/mol). Thereafter, FA release continued at 10-15 nmol per min mainly in Qrv while the rate of H-FABPc release decreased. During Ca2+ repletion, tissue FA content raised rapidly from 168 +/- 20 to 1918 +/- 107 nmol/g dry weight. These findings suggest that after severe cardiac damage initially FA is released bound to H-FABPc, whereas further FA release occurs in a non-protein bound manner.
Vork
M M
MM
Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), University of Limburg, The Netherlands.
Glatz
J F
JF
van der Vusse
G J
GJ
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000473:pathology; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism* / Q000473:pathology; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010477:Perfusion; D051381:Rats; D011917:Rats, Inbred Lew; D014867:Water / Q000378:metabolism
D002352:Carrier Proteins; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D014867:Water; D002118:Calcium