Action of Serotonin on Sodium-Potassium Activated ATPase in Rabbit Red Cell Membrane

토끼 적혈구막의 NaK ATPase의 활성도에 대한 serotonin의 작용

  • Chung, Soon-Tong (Department of Physiology, School of Medicine, Kyung Hee University) ;
  • Park, Chul-Bin (Department of Physiology, School of Medicine, Kyung Hee University) ;
  • Koh, Il-Sup (Department of Physiology, School of Medicine, Kyung Hee University)
  • 정순동 (경희대학교 의과대학 생리학교실) ;
  • 박철빈 (경희대학교 의과대학 생리학교실) ;
  • 고일섭 (경희대학교 의과대학 생리학교실)
  • Published : 1976.06.30

Abstract

The action of serotonin on the sodium plus potassium activated ATPase activity in the rabbit red cell membrane has been investigated. The experiments were also designed to determine the mechanism of action of serotonin on the ATPase activity. The following results were obtained. 1) The NaK ATPase activity of rabbit red cell ghosts is stimulated by low concentration of serotonin but inhibited by higher concentration, and the concentration of serotonin for maximal activity is about 2mM. The pH optimum for the serotonin sensitive component is 8.0. 2) The activating effect of serotonin on the ATPase, with a given concentration of sodium in the medium, is increased by raising the potassium concentration but the ratio of activity is decreased. 3) The activating effect of serotonin on the ATPase, with a given concentration of potassium in the medium, is increased by raising the sodium concentration but the ratio of activity is decreased. 4) The ATPase activity is increased by small amounts of calcium but inhibited by larger amounts and the ratio of activity by serotonin is decreased by small amounts of calcium but increased by larger amounts. 5) The action of serotonin on the ATPase activity was not related to the amino group of lysine, the hydroxyl group of threonine, the carboxyl group of aspartic acid, or the imidazole group of histidine. 6) The action of serotonin on the ATPase activity is due to sulfhydryl group of the enzyme of NaK ATPase.

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