Figure 6
Ca2+ is released from intracellular caffeine-sensitive stores. When caffeine-sensitive stores were depleted by caffeine (30 mM), a subsequent decline in [Ca2]i was observed, and no increase in [Ca2]i was provoked by (A, B) 20:1 cafedrine/theodrenaline, (C, D) cafedrine alone, or (E, F) theodrenaline alone. The Ca2+-free control group was represented by the same 30 cells in each chart. FURA-2 340/380 ratio was normalized after a 100-s resting period, and each group consists of 30 cells from at least three different coverslips, ensuring independent measurements. Scale bar width represents 100 s. n = number of individual cells, ***p < 0.001, ns: not significant, Wilcoxon rank sum test was used to test caffeine alone vs. drug preparation during inhibition, otherwise Mann–Whitney U test, adjusted α-level = 0.013. ⊥ SEM, box and whisker plots indicate median, interquartile range (box), minimum and maximum (whiskers).
