PIPERAMIDE-INDUCED MORPHOLOGICAL CHANGES IN CHOROID PLEXUS

Piperamide maleate was administered orally to mice, rats, Mongolian gerbils, monkeys and miniature pigs for periods ranging from 2 days to 50 wk at dose levels of 60-488 mg/kg body weight/day. In rats, microscopic examination of the choroid plexus showed a slight hydropic vacuolization of the epithelium in all ventricles after only 2 days of treatment. A marked degree of vacuolization was found after 8 days, associated with an increased volume of the choroid plexus and a decrease in the ventricular flow space available for the circulation of cerebrospinal fluid. Long-term experiments resulted in the development of hydrocephalus internus presumably due to a blockade of the intraventricular circulation and an overproduction of cerebrospinal fluid. All morphological changes were reversible. The same type of vacuolization was found in mice but not in gerbils or monkeys. The compound was neurotoxic to miniature pigs but no vacuolization of the choroid plexus epithelium was observed. © 1968.