Xd. Wang et al., ACTIVATION OF CL- CURRENTS BY INTRACELLULAR CHLORIDE IN FIBROBLASTS STABLY EXPRESSING THE HUMAN CYSTIC-FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR, Canadian journal of physiology and pharmacology, 71(9), 1993, pp. 645-649
The C1(-) conductance of a mouse fibroblast cell line (LTK(-) cells) t
hat was stably transfected with the human CFTR (cystic fibrosis transm
embrane conductance regulator) complementary DNA was studied. Single C
1(-) channel activity was observed only after treatment of the cells w
ith forskolin, the single-channel conductance being 6.2 +/- 0.2 pS wit
h a linear current-voltage relationship. In CFTR(+) cells, the whole-c
ell current at +90 mV increased from 7.3 +/- 2.7 pA/pF (n = 12) to 46.
1 +/- 11.2 pA/pF (n = 5) after addition of dibutyryl-cyclic AMP (10(-4
) M) to the bath. Increasing the intracellular C1(-) concentration to
150 mM activated linear C1(-) currents in the absence of cyclic AMP in
CFTR(+) (n = 42) but not in CFTR(-) cells (n = 4). Similar C1(-) curr
ent was also activated by high intracellular I- concentration. These r
esults indicate that the CFTR-induced C1(-)conductance in LTK(-) cells
can be activated by either cyclic AMP or high intracellular halide co
ncentrations.