[Intrathecal perfusion of ACNU neurotoxicity and intrathecal pharmacokinetics in dogs].

We studied the feasibility of intrathecal ACNU perfusion therapy against subarachnoid dissemination of malignant glioma. Intrathecal perfusion was performed in adult dogs by constant drip administration of 1 to 2 mg ACNU dissolved in 10 to 20 ml of lactate Ringer solution into the lateral ventricle and cerebrospinal fluid drainage through the lumbar puncture. The perfusion time was changed from 15 to 71 min. A bolus injection of 2 mg ACNU was also tested in one dog. No neurological symptom was noted during and after perfusion, and histological examination reveal only a minimum denudation of ependyma in a small area. Concentration of ACNU in CSF and serum were measured by HPLC (high-performance liquid chromatography). ACNU was detected in lumbar CSF only by perfusion, not by bolus injection, and the maximum concentrations were 6.26 to 25.76 micrograms/ml. The elimination phase of ACNU in lumbar CSF followed linear kinetics and the half-time was 18 min on average. AUCs (area under the drug concentration-time curve) were 346 to 896 micrograms.min/ml and they were the equivalent of in vitro cell kills in excess of 3 logs for rat 9L gliosarcoma and human glioma 126 cells. Serum concentration was 0.10 micrograms/ml in maximum. These findings suggest the feasibility of intrathecal ACNU perfusion therapy against subarachnoid dissemination of malignant glioma and warrant further studies.