Long-term effect of electroshock treatment on the entry of calcium into the cerebroventricular fluid in the rat.

The rate of appearance (Ra) of calcium (Ca) in the cerebroventricular compartment of urethane-anesthesized rats was determined by two methods: one is measurement of isotope dilution during ventricular-cisternal perfusion with artificial cerebrospinal fluid (CSF) containing 45Ca, the other is estimation of the rate of entry of 45Ca from plasma after rapid injection of tracer 45CaCl2 intravenously. Electroshock treatment (EST) for 3 successive days resulted in a marked increase in the rate of entry of calcium from blood to CSF. The effect of EST on the permeability of the blood-CSF barrier to Ca could be observed even 24 hr after the generalized seizure induced by electroshock has terminated.