Secretion of cerebrospinal fluid by the ventricular ependyma of the rabbit

Abstract

An aqueductal-anterior 4th ventricular perfusion system was described in the rabbit which allows measurement of fluid and solute exchanges occurring between brain and cerebrospinal fluid (CSF). It was shown, by direct volume and inulindilution measurements, that there was a net fluid accretion of 0.33 [mu]l cm-2 min.-1 within the experimental perfusion system. This volume flow was charged to the secretory activity of the ventricular ependyma. The rate of secretion was partially inhibited by topical 2,4-dinitrophenol (0.05 m[image]) and intravenous acetazolamide (100 mg/kg). The total area of ventricular ependyma in the rabbit was 12.8 cm2, and the weight of choroid plexus tissue in the lateral and fourth ventricles was 22.8 mg. The rate of CSF formation attributed to the ventricular ependeyma and the choroid plexus in the rabbit is 4.23 [mu]l min.-1 and 8.44 [mu]l min.-1, respectively. Therefore, in the rabbit, the total intraventricular rate of CSF formation is 12.67 [mu]l min.-1.