Fig. 3. (A ) Nortriptyline has no effect on Ca-activated Cl channels. Intracellular injection of CaCl2(final concentration, 10 μm; second bar ) induced Cl currents similar to those induced by lysophosphatidic acid (LPA) (100 μm; black bar ). Nortriptyline (10 μm) did not affect Ca-induced Cl currents (third bar ; percentage of control). Data are mean ± SD. (B ) Effects of protein kinase C (PKC) on LPA signaling. PKC inhibition with chelerythrine (50 μm) did not affect the inhibitory effect of nortriptyline (10 μm) on LPA (100 μm)–induced Cl currents (percentage of control). Data are mean ± SD. *P < 0.05.