Figure 6

Verapamil pretreatment protects the pancreatic cells against MTZ-induced cytotoxic damage in zebrafish embryos. (A) Schematic timeline showing the experimental design and drug treatments. At 3 days post fertilization (dpf), four groups of embryos were treated as follows: Group 1, untreated embryos; Group 2, embryos treated with 10 µM verapamil for 72 h; Group 3, embryos treated with 10 µM verapamil for 24 h, followed by drug removal and administration of 10 mM MTZ for 48 h; Group 4, embryos treated with 10 mM MTZ at 4 dpf for 48 h. Insulin-producing pancreatic cells co-expressing mCherry fluorescence reporter protein (ChFP) were imaged at 4 dpf (T0) and 6 dpf (T1). For each group, the differences in ChFP intensity between T0 and T1 were determined. (B) Representative images of pancreatic cells in each group at T1. Inserts depict the magnified ChFP area. Images were taken using Stereo discovery 1.2 ZIESS microcopy. (C) Quantification of ChFP intensity in four groups at T1. No significant difference in fluorescence intensity was found between Groups 1 and 2. However, the fluorescence intensity in Group 3, which was pretreated with verapamil, was significantly higher as compared to Group 3, which was not pretreated with verapamil. Experiments were performed in triplicates (n = 20–30 embryos/group). Data represents the mean ± SEM values. ns: non-significant.