Meglumine iothalamate (280 ml I/ml) and sodium iothalamate (400 mg I/ml) in doses of 700 mg I/kg bw, were injected i.v. as a bolus in dogs. Renal size, urine flow rate, arterial pressure, renal blood flow and mean transit time and renal blood volume were measured before and after injection. All changes were qualitatively and quantitatively identical for both drugs. They produced a small transient renal shrinkage followed by a greater and prolonged renal enlargement. During the period of renal enlargement, urine flow increased. The time course of the enlargement paralleled the increase of urine flow rate. Renal blood flow also increased but both the mean transit time and renal vascular volume decreased. Therefore, the kidney size increase after i.v. injection of large doses of urographic contrast media cannot be attributed to an increased volume of the vessels. Most likely it is caused by diuresis-induced increase in the volume of the tubules.

Animals↗

PubMedDate not supplied

Uptake of contrast materials by experimental acute myocardial infarctions: a preliminary report.

The concentration of iodine within infarcted and normal myocardium after intravenous administration of contrast material was determined by fluorescence excitation analysis in seven dogs at 48 hours after coronary arterial ligation. The iodine concentration of infarcted myocardial tissue was several times greater than normal myocardium after administration of meglumine/sodium diatrizoate, iodipamide, and an experimental polymer of iothalamic acid.

Acute Disease↗

PubMedDate not supplied

Direct myocardial effects of intracoronary administration of new contrast materials with lost osmolality.

The effects of LV dynamics of the intracoronary administration of three new contrast materials with reduced osmolality were compared with those of a monomeric ionic material, sodium iothalamate, and the nonionic material, metrizamide. In eight anesthetized dogs, the monacid dimer, P286, caused increases in LV dimensions and decreases in LV systolic pressure and parameters of the contractile state. The changes were less than those caused by sodium iothalamte. The alterations in LV function tended to be greater, but not significantly so, during systemic hypoxemia compared to the normal state. The nonionic materials, P297 and iopamidol, like metrizamide, caused no deleterious effects on LV dynamics in either the normal or hypoxemic state. Nonionic materials actually caused a slight increase in parameters of the LV contractile state.

Animals↗

PubMedDate not supplied

Spectral analysis of Lapine EEG: neurotoxicologic evaluation of new nonionic contrast media.

Effects of the injection of 0.25 ml of nonionic radiocontrast media (280 mg I/ml) and/or istonic and/or hypertonic mannitol into the subarachnoid space on the low frequencies (2--5 Hz) of the EEG were studied in nonanesthetized, curarized rabbits. Compared to the noninjected controls, mannitol did not cause any significant EEG spectrum shifts. P-297 and iopamidol caused a slight decrease in the energy content of the 2--5-Hz band, while DS-1-132 and the nonionic dimer ZK 32347 caused a moderate increase. Since an increase in the slow-wave component of the EEG indicates a pacemaking activity, while a decrease indicates stimulation or irritation, none of the tested nonionic media appear to be biological inert. In this test P-297, iopamidol, and DS-1-132 caused fewer disturbances than metrizamide.

Animals↗

PubMedDate not supplied

Combined methods for assessment of neurotoxicity: testing of new nonionic radiographic media.

A battery of tests for toxicity assessment of new contrast media is reviewed. Cell toxicity in a protozoan culture (Blepharisma americanum); lethal dose determination in mice; EEG Spectral analysis following cisternography in rabbits; ED50 and LD50 determination by intra- and pericerebral injection in rats; intracisternal injection in chronically cannulated, nonanesthetized rats; and aversive conditioning by intracisternal injection in rats were found complementary. By these methods, novel nonionic media phenyl-sugar-ether DS-1-132 and DL-2-99 were found comparable to iopamidol, while all three compounds were superior to metrizamide.

Animals↗

PubMedDate not supplied

Syntheses of new nonionic radiographic contrast media: acylamino-triiodophenyl ethers of sugars.

New, potentially useful radiographic contrast media, employing hexoses attached to the triiodophenyl moiety by an ether bond, have been synthesized and tested. Two of the nitro groups in trinitrobenzene were displaced by two fully protected glycose-3-yl residues. The bis-ethers (IV) were successively reduced, iodinated, acylated, and then subjected to base and/or acid catalyzed deprotection to obtain the acylamino-triiodophenyl ethers (VIII). The bis-glucose-3-yl ether (VIIIa) was converted into the corresponding bis-arabinos-2-yl ether (XIII) by standard methods. These sugar ethers have high water solubility, hydrolytic stability, and low toxicity. The glycolyl-bis-hexose ether DL-2-98, which has the lowest neurotoxicity in this series of compounds, is comparable to iopamidol, and is potentially useful as a new nonionic radiographic contrast agent.

Animals↗