The influence of lactate and dipyridamole on myocardial fatty acid metabolism in man, traced with 123I-17-iodoheptadecanoic acid.
Changes in myocardial metabolism can be detected externally by registration of time-activity curves after administration of radioiodinated fatty acids. In this scintigraphic study the influence of lactate on fatty acid metabolism was investigated in the normal human myocardium, traced with 123I-17-iodoheptadecanoic acid (123I-17-HDA). In patients (paired, n = 7) lactate loading decreased the uptake of 123I-17-HDA significantly from 27 (control: 22-36) to 20 counts/min/pixel (16-31; p less than 0.05 Wilcoxon). The half-time value increased to more than 60 min (n = 5), oxidation decreased from 61 to 42%. Coronary vasodilatation, a well-known side effect of lactate loading, was studied separately in a dipyridamole study (paired, n = 6). Coronary vasodilatation did not influence the parameters of the time-activity curve. These results suggest that changes in plasma lactate level as occurring, among other effects, during exercise will influence the parameters of dynamic 123I-17-HDA scintigraphy of the heart.
Duwel
C M
CM
Department of Cardiology, Free University Hospital, Amsterdam, The Netherlands.
Visser
F C
FC
van Eenige
M J
MJ
Westera
G
G
Roos
J P
JP
D000368:Aged; D004176:Dipyridamole / Q000494:pharmacology*; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007457:Iodine Radioisotopes; D007773:Lactates / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D011877:Radionuclide Imaging
D005227:Fatty Acids; D007457:Iodine Radioisotopes; D007773:Lactates; C027252:17-iodoheptadecanoic acid; D004176:Dipyridamole