Red-cell trapping in the rat renal microcirculation induced by low-osmolar contrast media and mannitol

• RATIONALE AND OBJECTIVES: In acute renal failure after ischemia, intravascular obstruction by trapped red blood cells in the microvasculature of the renal outer medulla is a consistent finding. The influence of intravenously injected contrast media (CM) on such obstruction was investigated. METHODS: Anesthetized rats were subjected to 45 minutes of unilateral renal ischemia. Red-cell trapping in ischemically injured kidneys and in the contralateral uninjured kidneys was estimated from the intrarenal distribution of 51Cr-labelled erythrocytes after injection of ioxaglate or iopamidol in a dose of 1,600 mg I/kg body weight. As an osmolar control substance, mannitol (950 mOsm/kg) was given to a third group and isotonic Ringer's solution was administered to a fourth group. RESULTS: In the uninjured kidneys, treatment with ioxaglate or mannitol resulted in no red-cell trapping, while the iopamidol-treated group showed red-cell trapping in the inner stripe of the outer medulla in a dose-dependent manner. In the ischemically injured kidneys, both CM and mannitol enhanced the red-cell trapping in the inner stripe of the renal medulla. CONCLUSION: The results indicate that intravenously administered ioxaglate and iopamidol enhance the microvascular obstructions evoked by ischemic injury and that iopamidol may induce local impairment in renal medullary microcirculation in a normal kidney.

Nyckelord

Animals

Dose-Response Relationship; Drug

Erythrocyte Volume/drug effects

Erythrocytes/*drug effects

Iopamidol/*pharmacology

Ioxaglic Acid/*pharmacology

Ischemia/*physiopathology

Kidney/*blood supply

Male

Mannitol/*pharmacology

Microcirculation

Rats

Rats; Sprague-Dawley

MEDICINE

MEDICIN

Publikations- och innehållstyp

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art (ämneskategori)