[Effects of sodium fluoride on the activity of Ca2+Mg(2+)-ATPase in synaptic membrane in rat brain]

Effects of sodium fluoride on Ca2+Mg(2+)-ATPase activity of synaptic membrane in rat brain were studied with in vitro or in vivo methods. Concentrations of sodium fluoride of 0.3, 1.6, 8.0, 20.0 and 40.0 mmol/L can significantly inhibit the activity of the enzyme with proportions of 6.6%, 18.0%, 41.0%, 55.5% and 63.1%, respectively, and with a half inhibitory concentration of 14.8 mmol/L reflecting an obvious dose-effect and time effect relationship. Analysis of enzyme substrate kinetics showed the effect that sodium fluoride had was a non competitive inhibition. Activity of Ca2+Mg(2+)-ATPase on synaptic membrane in female rat brain showed a decreasing tendency after feeding with water fluorinated with 5, 15 and 50 mg/L of fluoride during their gestation and lactation for 50 days, and that in their newborn offsprings with 5 and 50 mg/L of fluoride was inhibited by 11.3 and 32.1%, respectively.