Na-K-ATPase, which is activated by Na+ and K- at physiological concentrations, have a high ability for sodium and potassium transport and material transport through the cell membrane. And the activity of this enzyme is specifically inhibited by ouabai...
Na-K-ATPase, which is activated by Na+ and K- at physiological concentrations, have a high ability for sodium and potassium transport and material transport through the cell membrane. And the activity of this enzyme is specifically inhibited by ouabain.
Oxy -locin is a neurohormone to be secreted from the posterior pituitary gland. And it is used widely in the clinical field as a agent for the onset or maintenance of labor and as a stimulant for the milk ejection. Also this hormone causes antidiuretic effect as a continous intravenous infusion. This suggested that oxytocin may have any effect on the material transport through the cell membrane. So, this study was attempted to investigate the effect of oxytocin on the activity of Na-K-ATPase in the red cell ghosts of rabbits.
The red cell ghosts were purified by the method of Rosenberg and Guicotzi, and the amount of t Ic decomposed inorganic phosporus, that is the indicator of Na-K-ATPase activity, was measured by the method of Fiske and Subbarow.
The results were summarized as follows
l. The activity of Na-K-ATPase of the control group was 3.03±0.36 μM Pi/g protein/l0 min.
2. The activities of ATPases were showed a tendency to inhibit by the dosage of oxytocin 0.5 I.U., but it was not significant except total ATPase activity(p<0.05).
3. The activities of total ATPase and Na-K-ATPase were significantly inhibited by the
dosage of oxytocin 1.0 1.U. (p<0.05 and p<0.001).