Figure 7.

Diagram of the feedback control system, illustrating the mechanisms for regulation of intracellular Δp in lens surface cells. A positive arrow indicates that increased activity in the upstream block causes an increase of activity in the downstream block, and a negative arrow indicates that increased activity in the upstream block causes a decrease of activity in the downstream block. For example, an increase in Na/K ATPase activity due to Src activation causes a decrease in osmolarity, whereas inhibition of Na/K ATPase activity due to Akt activation causes an increase in osmolarity. In the TRPV1 initiated path, Akt activation inhibits Na/K pump activity; however, increased Na/K pump activation reduces intracellular osmolarity, so the result is inhibition of inhibition and is thus a stimulatory effect on osmolarity.