Standing potential and c-wave during changes in PO2 and flow in the perfused cat eye

Abstract

Changing flow rate (F) in arterially perfused cat eyes concomitantly alters the supply of O2 and greatly affects electrical signals: increasing F increases the standing potential (SP) and decreasing F induces the opposite. Corresponding effects on c-wave are more variable. To separate changes in supply of O2 from changes in F we performed two types of experiments: (1) changing supply of O2 while keeping F constant; this was done by switching to a perfusate of different PO2: and (2) changing F while keeping the supply of O2 constant; this was done by switching to hypoxic or hyperoxic perfusates and adjusting F to keep the b-wave amplitude constant. Results (1): Decrease in PO2 left the SP essentially unaffected, but increased the c-wave. Increase in PO2 tended to increase the SP and to decrease the c-wave. Results (2): Isolated decrease in F did not affect the SP consistently and left the c-wave unchanged. Isolated increase in F often increased the SP, but also left the c-wave unchanged. Covariation between SP and amplitude to the c-wave was absent during hyperoxia.