The comparative effects of calcium channel blockers in an experimental colitis model in rats

In this study two calcium channel blockers (CCB), diltiazem and verapamil, which demonstrate their effects on two different receptor blockage mechanisms, were assessed comparatively in an experimental colitis model regarding the local and systemic effect spectrum.

Eighty male Swiss albino rats were divided into eight groups (n:10 each): Group I) colitis was induced with 1 ml 4% acetic acid without any medication. Group II) Sham group. Group III) Intra-muscular (IM) diltiazem was administered daily for five days before inducing colitis. Group IV) IM verapamil was administered daily for five days before inducing colitis. Group V) Transrectal (TR) diltiazem was administered with enema daily for two days before inducing colitis. Group VI) TR saline was administered four hours before inducing colitis. Group VII) TR diltiazem was administered with enema four hours before inducing colitis. Group VIII) TR verapamil was administered with enema four hours before inducing colitis. All subjects were sacrificed 48 hours after the colitis induction. The distal colon segment was assessed macroscopically and microscopically for the grade of damage, and myeloperoxidase (MPO) activity was measured.

All the data of the control colitis group (group I), including the microscopic, macroscopic and MPO activity measurements, were significantly higher than in the groups in which verapamil and diltiazem were administered over seven days (3.100+/-0.7379 to 1.300+/-0.9487 and 1.600+/-0.9661) (p<0.05). The data of the Sham group, group II, were less than the other groups in which colitis was induced (p<0.05). For the local effect spectrum, after the assessment of groups V-VIII, the control colitis group (group I) and group VI had significantly higher values than the others (3.300+/-0.4830 to 1.800+/-0.6325 and 1.700+/-0.8233 (p<0.05).

Calcium channel blockage has systemic and local effects on the colitis model.