Abstract:We determined the effects of either topical or systemic calcium channel antagonists on rabbit intraocular pressure (IOP). Topical nifedipine, verapamil or diltiazem had no significant effect on IOP. Intravenous verapamil and nifedipine caused statistically significant reductions in IOP between 2 and 6 h after administration; the nifedipine response followed an increase in IOP at 30 min. Diltiazem, given 3 times daily for 3 days, caused no pressure change. In the rabbit, therefore, calcium channel antagonists h… Show more
“…Previous reports have indicated that systemic administration of some Ca# + channel blockers either has no effect or causes a mild, but significant, reduction in IOP in conscious or anesthetized rabbits (Green and Kim, 1977 ;Beatty et al, 1984 ;Payne et al, 1990). In particular, Payne et al (1990) found that i.v. administration of verapamil or nifedipine caused a significant reduction in IOP between 2 and 6 hr after their administration in rabbits.…”
“…Previous reports have indicated that systemic administration of some Ca# + channel blockers either has no effect or causes a mild, but significant, reduction in IOP in conscious or anesthetized rabbits (Green and Kim, 1977 ;Beatty et al, 1984 ;Payne et al, 1990). In particular, Payne et al (1990) found that i.v. administration of verapamil or nifedipine caused a significant reduction in IOP between 2 and 6 hr after their administration in rabbits.…”
“…16 However, Segarra and colleagues have stated topical application of verapamil and nifedipine lowers IOP in conscious rabbits. 17 Another study demonstrates that calcium channel blockers in combination with antiglaucoma medications signifi cantly lower IOP in the primate eye.…”
It seems that topical verapamil has a similar effect to timolol in patients with open-angle glaucoma, so it can be considered as a lowering intraocular pressure agent in glaucoma patients.
“…Both of these inhibitions may be partially reversed with verapamil [11]. Calcium channel blockers have widespread physiological and pharmacological actions [12][13][14]. In wound healing, calcium antagonists have been shown to inhibit platelet aggregation and activation, chemotaxis of polymorphonuclear leukocytes and fibroblast response [15][16][17].…”
Objective: To investigate the effect of diltiazem, a calcium channel blocker, on healing of the traumatic urethral inflammation when applied systemically or locally. Materials and Methods: 21 adult male Wistar rats (230–250 g) were assigned to group 1 (n = 7) = control, group 2 (n = 7) = local application or group 3 (n = 7) = systemic application. In group 1, only a urethral injury was achieved at the 12-o’clock position by gently introducing and drawing a tiny hook in the urethra until urethral bleeding occurred. In group 2, after the same procedure, 10 mg/kg diltiazem was applied retrogradely via a 22-gauge Angiocath intraurethrally for 5 consecutive days, while the same account of the drug was administered intraperitoneally in group 3. After 21 days, the rats were sacrificed for urethrectomy. Pathologically, the thickness of connective tissue, the regularity of the epithelial lining, the presence of the inflammation and the density of collagen were evaluated with Masson’s trichrome staining. The Mann-Whitney U test was used for statistical analyses. Results: The mean connective tissue thickness was 0.77 ± 0.39, 1.01 ± 0.77 and 0.93 ± 0.53 µm in groups 1, 2 and 3, respectively. The differences between the groups were insignificant (p > 0.05). The hyperplastic epithelial lining in the study groups, with both systemic and local applications, was markedly infrequent and the inflammation was less prominent. However, these differences did not reach statistical significance. Conclusions: Diltiazem appears not to have any preventive effect on connective tissue formation when applied locally or systemically in our urethral injury model.
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