Reduced cerebrospinal fluid production in the rat and rabbit by diatrizoate. Ventriculocisternal perfusion

The effect of the radiographic contrast agent diatrizoate on cerebrospinal fluid (CSF) production was determined by ventriculocisternal perfusion. The lateral ventricle and cisterna magna of anesthetized rats and rabbits were cannulated stereotactically and perfused continuously with a H-3 inulin-labeled artificial CSF solution. Baseline collections of CSF began after steady state outflow was established; then, diatrizoate was administered intravenously for 1 hour. The baseline rate of CSF production was compared with that measured during and after the diatrizoate infusion. The baseline CSF production rate was 3.7 +/- 0.1 and 18.6 +/- 1.4 microL/minute in the rat and rabbit, respectively. Diatrizoate decreased the CSF production rate to 2.9 +/- 0.1 and 13.9 +/- 0.9 microL/minute. This reduced rate continued for at least 90 minutes after the end of the diatrizoate infusion, averaging 3.0 +/- 0.1 and 12.0 +/- 0.6 microL/minute in the rat and rabbit, respectively. These results confirm that decreased CSF production induced by the intravenous administration of diatrizoate is not species specific and is observed with the ventriculocisternal perfusion method of measuring CSF production rates.