Different effect of diatrizoate and iopamidol on prostaglandin synthesis in perfused hamster lungs.

The synthesis of prostaglandins and other metabolic products of arachidonic acid (AA) was investigated in isolated perfused lungs of hamsters during the infusion of various concentrations of meglumine diatrizoate and iopamidol. Forty nmol of 14C-AA was infused into the pulmonary circulation with radiographic contrast media (RCM), and prostaglandins, thromboxanes, and metabolites of lipoxygenases were analyzed from the nonrecirculating perfusion effluent. Arachidonate infusion increased the perfusion pressure. This pressor response was decreased by iopamidol but was not changed by diatrizoate. The amount of radioactivity was decreased in the perfusion effluent and increased in lung lipids by iopamidol. Meglumine diatrizoate increased radioactivity in the effluent with minimal effects on the distribution of radioactivity in lung lipids. Almost all arachidonate metabolites were decreased significantly by iopamidol when compared with hypertonic saline whereas diatrizoate caused an increasing trend in the formation of the metabolites of AA. The present study shows that ionic and nonionic RCM have different effects on the metabolism of arachidonic acid.