Reversal of one-kidney, one-clip hypertension in rats effects on myocardial na⁺, k⁺-atpase, arterial na⁺-k⁺pump, arterial membrane potential, and plasma na⁺-k⁺pump inhibitory activity

We have previously reported that myocardial mi­crosomal Na⁺, K⁺-ATPase activity, arterial wall oua­bain-sensitive “Rb uptake, and arterial smooth muscle cell membrane potentials are decreased and plasma Na+-K+ pump inhibitory activity is in­creased in rats during the fifth week of one-kidney, one-clip hypertension. We here report measure­ments of these four parameters and blood pressure following unclipping. A new series of rats with one-kidney, one-clip hypertension was prepared. Each animal was paired with a one-kidney, sham- clipped (nonconstricting clip) control rat. After 5 weeks, the clips were removed. In the hypertensive animals arterial pressure promptly (within 3 h) re­turned to normal and remained at that level for 7 observation days. On the third day following un­clipping, all four parameters were not significantly different from those in the paired control animals. On the seventh day following unclipping, three of the four parameters were not significantly different from those in the paired control animals and arte­rial ouabain sensitive “Rb uptake was slightly in­creased relative to the value in the control animals. These studies invite further inquiry into the possi­ble role of plasma Na⁺-K⁺Pump inhibitory activity in the genesis and maintenance of the hypertension in this model.