Na,K-ATPase is essential for the regulation of cytoplasmic Na and K levels in lens cells. Studies on the intact lens suggest activation of tyrosine kinases may inhibit Na,KATPase function. Here, we tested the influence of Lyn kinase, a Src-family member, on tyrosine phosphorylation and Na,K-ATPase activity in membrane material isolated from porcine lens epithelium. Western blot studies indicate...