FIGURE 2.

Differential inhibition of catecholamine secretion by CST variants in an Indian population. PC12 cells cultured in poly l-lysine-coated 12-well plates were preloaded with [³H]norepinephrine and treated with 60 μm nicotine without/with ascending concentrations (0.1–5 μm) of CST peptides. Each data point represents the mean ± S.E. of three separate wells. The control (100%) is norepinephrine secretion when challenged with 60 μm nicotine alone without peptide. Results of two-way ANOVA are shown, factoring for the effects of peptide, concentration, and peptide-by-concentration interaction on the net [³H]norepinephrine secretion. * and ** indicate p < 0.05 and p < 0.01 with respect to CST-Ser-364, whereas # indicates p < 0.01 with respect to CST-Val-367 (by two-tailed t test).