Incorporation of radioiodinated fatty acids into cardiac phospholipids of normoxic canine myocardium.
The aim of this study was to assess the phospholipid distribution of radioiodinated 17-iodoheptadecanoic acid (IHDA), 15-(p-iodophenyl)pentadecanoic acid (p-IPPA) and 15-(p-iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPPA) under normoxic conditions and to compare these data with the fatty acid composition of the phospholipid classes. After simultaneous i.v. injection of the radioiodinated fatty acids (I-123-IHDA; I-131-p-IPPA; I-125-DMIPPA) in open-chest dogs seven myocardial biopsies were taken over 40 min (n = 26). After lipid extraction of the biopsies the organic phase was analyzed for both neutral and polar lipids by two different TLC systems. The following polar lipid fractions were analyzed: lysophosphatidylcholine (LPC), sphingomyelin (SPH), phosphatidylcholine (PC; lecithin), phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG; cardiolipin) and neutral lipids. Fractions were counted in a gamma well counter and corrected for cross-over and recovery. Results of the polar phospholipids analysis showed that IHDA has the highest incorporation into the phospholipids. The IHDA was mainly incorporated into PI (45.6%) followed by PC (30.9%), PE (14.0%) and PS (5.6%). The p-IPPA was predominantly incorporated incorporated into PC (37.2%), followed by PS (20.1%) and PE (13.7%). In contrast to IHDA, incorporation of p-IPPA into PI was small (6.4%). The DMIPPA analogue was incorporated into phospholipids to only a very small degree, compared to IHDA and p-IPPA.(ABSTRACT TRUNCATED AT 250 WORDS)
Sloof
G W
GW
Dept. of Cardiology, Metabolic Laboratory, Free University Hospital Amsterdam, The Netherlands.
Visser
F C
FC
Teerlink
T
T
Comans
E F
EF
Eenige van
M J
MJ
van der Vusse
G J
GJ
Knapp
F F
FF
D000818:Animals; D004285:Dogs; D005227:Fatty Acids / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects; D007462:Iodobenzenes / Q000493:pharmacokinetics; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*
D005227:Fatty Acids; D007462:Iodobenzenes; D008563:Membrane Lipids; D010743:Phospholipids; C049337:15-(4-iodophenyl)-3,3-dimethylpentadecanoic acid; C027252:17-iodoheptadecanoic acid; C025391:omega-(4-iodophenyl)pentadecanoic acid; D010100:Oxygen