Immunodetection of Na,K-ATPase in guinea-pig retinal layers, cornea and lens

Na,K-ATPase was detected in crude microsomes of guinea-pig retinal layers, cornea and lens by immunoblotting using antibodies generated against purified kidney Na,K-ATPase. The antiserum cross-reacted with the alpha catalytic subunit of the enzyme from the eye tissues but not the beta glycoprotein subunit, suggesting a high degree of tissue-to-tissue variability in the beta subunit. The apparent molecular weight of the alpha subunit in retinal layers, cornea and lens was 95 Kd which is similar to alpha subunit in kidney. In the retinal layers and cornea, the antiserum detected proteolytic fragments of the enzyme. This method can be used to detect aggregates or proteolytic fragments of Na,K-ATPase in disease states of eye tissues in which electrolyte imbalances have been implicated, such as in experimental and senile cataracts.