Extracellular transport properties of Aplysia californica intestine

Energetics of Potassium Ion Transport in Aplysia Gut

“…The increased Na + flux, and concomitant increased intracellular Na + activity, would then stimulate an extracellular serosal to cytosol K + flux (Table 3) which is mediated by a ouabain-sensitive Na + /K + -ATPase as is also shown in Table 3. Since it has been shown that the major portion of the SCC before and after AIB addition to the mucosal solution is a Clcurrent (Gerencser, 1981b) which is generated by a Clpump (Gerencser, 1996) there would be a decrease in the negativity of Ψ s by both the additive increased electrogenic Na + /K + -and Cl -pump activities; and, the linkage of Ψ m to Ψ s through a low resistance extracellular shunt (Gerencser and Loughlin, 1983) which would lead to a greater serosally-negative Ψ ms (Schultz, 1977) as shown in Table 1. When AIB is present in the mucosal bathing solution the against which the Na + /K + pump is moving Na + out of the cell across the BLM decreases significantly relative to across the BLM in the absence of AIB, as is shown in Table 1.…”