SECRETION OF CEREBROSPINAL FLUID BY CHOROID PLEXUS OF THE RABBIT

Blood flow in the principal draining vein of the choroid plexus of the lateral ventricle of the rabbit, which drains approximately the anterior 70% of the plexus, was measured by the analysis of motion pictures made during the injection of spheruler of 1-octanol. The relative loss of volume from the plasma compartment during the transit of blood was measured by the comparison of relative cell volumes in aortic blood and in venous blood of the plexus. The blood flow of the plexus averaged 2.86 µl/mg min and the rate of production of cerebrospinal fluid .37 µl/mg min. The effect upon the relative rate of production of fluid of several inhibitors was tested and of these acetazolamide was effective both intravascularly and topically; cardiac glycosides were effective topically, but not when given intravenously; and cyanide and 2,4-dinitrophenol were ineffective topically.