The effects of aluminum chloride on the rate of secretion of the cerebrospinal fluid

The claim that AlCl 3 could produce 100% inhibition of cerebrospinal fluid secretion was investigated using ventriculocisternal perfusion in the rabbit, and it was shown that a large part of this inhibition was an artefact due to a pH sensitivity of Blue Dextran, used as an indiffusible marker, caused by AlCl 3. Thus the true inhibition found by us, using [ 3H]labeled markers, was about 33% and usually only partly reversible. Penetration of 22Na from blood into the perfused ventricles was partially inhibited by AlCl 3. The effects of some other acid buffer systems, namely acetate and phosphate, on rate of secretion were measured; the results were highly variable. When mean arterial pressure was measured, it was found to be unaffected by AlCl 3 but elevated with acetate and phosphate buffer mixtures.