Effect of calcium on anxiolytic activity of diazepam and verapamil in rats

Objective: To analyze the role of calcium in anxiety and its effect on anxiolytic activity of diazepam and verapamil.
Materials and Methods: Study was conducted using female albino rats in light and dark arena; a nonconflicting animal experimental model for anxiety. Animals were divided into six groups with six animals in each group. Test drugs, calcium gluconate (10 mg/kg), diazepam (1 mg/kg), verapamil (5 mg/kg), calcium + diazepam, and calcium + verapamil were administered intraperitoneally. Percentage of time spent in light arena and number of entries into light arena were the two parameters observed for 5 min after 30 min of drug administration. ANOVA test was used for statistical analysis.
Results: Compared to the control group, diazepam group, and calcium group, only calcium + diazepam group showed considerable increase in mean percentage of time spent in light arena. However, this increase was statistically insignificant. In the case of total number of entries into light arena, animals in calcium + diazepam group showed statistically significant increase in total number of entries into light arena when compared to calcium group and diazepam group.
Conclusion: Results of the study suggest that calcium may enhance the anxiolytic activity of diazepam, but has no effect on anxiolytic activity of verapamil.