J. Gorski et al., EFFECT OF A LOW-OSMOLALITY NONIONIC CONTRAST-MEDIUM (IOPROMIDE) ON BLOOD-PLATELET MEMBRANE-STRUCTURE AND AGGREGATION, European radiology, 5(5), 1995, pp. 543-546
Nonionic contrast media (NICM) used in radiology exhibit weaker antico
agulant properties than ionic media. This study was intended to evalua
te the effect of iopromide NICM upon the platelet aggregation and thei
r membrane structure (investigated by electron paramagnetic resonance
method with a spin label). Blood was collected directly from the left
ventricle during coronary angiography prior to and following the appli
cation of the contrast medium. These results were compared with in vit
ro examinations. Based on the spectral curves parameters that reflect
conformational changes in membrane proteins were determined. The iopro
mide-induced decrease in platelet aggregation examined in vitro with a
denosine diphosphate (ADP), collagen and ristocetine was statistically
significant. In vitro platelet membrane structure was modified signif
icantly with regard to both protein conformation and the accessibility
of sulfhydryl (-SH) and amino (-NH2) groups. In ex vivo studies the c
hanges in platelet aggregation was only observed with ADP, whereas in
the membrane-structure modifications were only noted regarding accessi
bility of -SH and -NH2 groups. We conclude that iopromide-induced plat
elet aggregation changes are most probably due to their membrane-struc
ture modifications, whereas the less-pronounced contrast effect ex viv
o is due to its rapid dilution in the inflowing blood. The results con
firm weak antiplatelet and anticoagulant influence of NICM in vivo.