The maintenance of balance between water and electrolyte is essential for keeping the lens transparent. The outflow of the Na+ ion from the membrane and inflow of the K+ ion both of which are sustained by the Na+ - K+ - ATPase, play an important role in maintaining this balance. In this study, by comparing the lens Na+ - K+ - ATPase activity in Spontaneous Hypertensive Rat(SHR) and Sprague-Dawley Rat (SDR), we determined the significance of increase in blood pressure and the change in the enzyme activity after control of blood pressure by administration of Inderal, an anti-hypertensive drug. The Na+ - K+ - ATPase activity was significantly lowered(P<0.01) in the lens of SHR compared to that of SDR. The longer the anti-hypertensive drug was administered and then controlled the blood pressure, the higher the recovery rate of the lowered Na+ - K+ - ATPase activity of SHR, rising up to about 50%. From the results of this study, it is suggested that the activity of lens Na+ - K+ - ATPase may be reversibly recovered after blood pressure control, and that the pathogenesis of high blood pressure-associated cataract may be partially prevented by controlling the blood pressure.
Adenosine Triphosphatases* ; Animals ; Blood Pressure* ; Cataract ; Membranes ; Propranolol ; Rats* ; Rats, Sprague-Dawley