To study the alterations of Na-pump in the 1-kidney, 1-clip hypertensive rat, made by partial ligation of left renal artery and by removal of right kidney, we determined Na, K-ATPase activity in the RBC and carried out the experiments of ^(86)Rb-uptake and ^(3)H-ouabain-binding from the RBC and aorta.
Results were as follows；
1. Blood pressure was significantly increased to 177.4/121.6 mmHg in 1-kidney, 1-clip hypertensive rat at 4 weeks after operation.
2. Na, K-ATPase activity in the RBC membrane of hypertensive rat was significantly decreased, compared to that of control rat(P<0.05).
3. Ouabain-sensitive Rb-uptake was significantly decreased in the RBC and aorta strip on hypertensive rat, compared to that of the control rat.
4. Bmax of the RBC and aorta strip in the ouabain-binding study was significantly decreased, but values of Kd was significantly increased in hypertensive rat.
From these results, it is suggested that decreased activity of Na-pump in hypertensive rat RBC and aorta strip, is due to the alteration of number and property of Na-pump.
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