A Study of Effect of Perindopril and Candesartan on Pain Perception in Albino Rats

Background&objectives: Pain is universally understood as signal of disease. It is unique among the sensation in that it has a built in unpleasant effect. It is the most common symptom that brings patient to physician attention. The cardiovascular and renal system shares a numerous anatomic and functional pathways with the nociception network. Besides well known role of Angiotensin system in Blood pressure control and an interaction of angiotensin and pain perception has been suggested. Hence this study was conducted to evaluate and compare the effect of Perindopril (ACEI) and Candesartan (ARB) on pain perception in albino rats.

Method: Inbred albino rats (Wistar strain) weighing 200-250g of either sex were used for the study. Animals were divided in seven groups containing 6 animals each (control group, treatment groups). Drugs were injected (i.p) as per the individualized dosages to the animals and the reaction time of animal's recorded using hot plate and tail flick latency method at different time points (pre-treatment, 15, 30, 60, 90 and 120 min post drug administration). The data collected were subjected to statistical analysis using SPSS.

Results: Following drug administration there was a dose dependent reduction in reaction time at different time points irrespective of the models and treatment groups. Significant reduction (p <0.05) in reaction time (hot plate model) was observed at highest doses (2mg/kg) in the treatment groups.

Conclusion: Both Perindopril (ACEI) and Candesartan (ARB) showed to have hyperalgesic effects on dose to dose basis in thermal induced pain models. It is also inferred that Perindopril produced more hyperalgesic effects than Candesartan on dose to dose basis.