[45Ca2+ and 3H-GABA transport in nerve endings separated from the cerebral cortex of rats with hypoparathyroidism]

Ca2+ blood serum level was reduced by 34.5% in rats with hypoparathyroidism (HPT) on the 7th-12th day after the damage of parathyroid glands. Synaptosomes isolated from the brain cortex of rats during this period accumulated in a normal medium more 45Ca2+ than synaptosomes from healthy animals. In potassium depolarization, control and experimental synaptosomes accumulated more 45Ca2+, however in HPT the increment in 45Ca2+ uptake in high potassium medium was less temperature-dependent. In normal medium 3H-GABA uptake and release by synaptosomes from the brain of rats with HPT slightly differed from those in the control. On the contrary, 3H-GABA release induced by synaptosome depolarization was depressed in HPT. It is suggested that nerve terminal excretory function disturbances contribute to increased excitability of the central nervous system in hypoparathyroidism.