Effect of Graded Osmolaltities of Saline Solution and contrast Media on Renal Extraction of PAH in the Dog

Abstract

The relative roles of osmolality and chemical structure of currently used radio-graphic contrast materials in producing a decrease in renal extraction of para-aminohippurate (E_PAH) were studied experimentally in dogs. Hypertonic saline solution produced a small but significant fall in E_PAH but all contrast agents compared to an equal osmolar load of saline solution effected a significantly greater fall in E_PAH. No significant differences could be found between sodium diatrizoate, methylglucamine diatrizoate and methylglucamine iothalamate when only E_PAH was considered. The data indicate that she effect of contrast media on the renal tubule cell is mediated by the organic iodinated molecule rather than the sodium or N-methylglucamine cation. No difference was found between the diatrizoate or she iothalamate molecules.