Figure 4.

Potassium and chloride currents evoked by gp120 in MDM. The ionic nature of currents elicited in MDM by gp120 from JRFL (A) and IIIB (B) was determined from the reversal potential (right) and with channel inhibitors (left). At peak activation, the outward JRFL current reversed direction at ≈−78 mV (A, top right) whereas the peak inward currents elicited by JRFL (A, bottom right) and IIIB (B, right) reversed at ≈5 mV (squares). In low Cl⁻ bath solution, the current voltage relationship of the inward current elicited by both Envs shifted to ≈+40 mV (circles). Charybdotoxin (100 nM) blocked the JRFL-evoked outward current, and NPPB (10 μM) blocked the inward currents activated by both Envs (A and B, left).