Inhibitory effect of prostaglandin A 2 on Na +-K + -ATPase activity in synaptic plasma membrane of rat brain in vitro

Abstract

1. 1. The Na + -K + -ATPase activity in the synaptic plasma membrane of rat brain was inhibited by PGA 2 in vitro. 2. 2. PGA 2 concentration required for 50% inhibition was 8.91 × 10 −5 M. 3. 3. Inhibition mode of PGA 2 for both ATP and Mg 2+ was uncompetitive type. 4. 4. PGA 2 was competitive and noncompetitive with Na + and K +, respectively. 5. 5. The K i values for PGA 2 inhibition for ATP, Na +, K + and Mg 2+ were 6.0 × 10 −5, 2.7 × 10 −5. 10.8 × 10 −5 and 0.6 × 10 −5 M, respectively.