Anti-vasospastic effects of botulinum toxin B pretreatment in animal models

Background: Botulinum toxin has been recently known for its vasodilatory effect. The main purpose of our study was to demonstrate the anti-vasospastic effect of botulinum toxin B in animal models. Method: In this prospective experimental rat study, we used 10 male Sprague-Dawley rats. The right and left inguinal areas (femoral vessels) served as the experimental and control groups, respectively. Three days prior to the experimental procedure, botulinum toxin B and normal saline were subcutaneously injected in the experimental and control groups, respectively. After three days, the vascular diameter and flow were measured. Then, phenylephrine was injected, and after one hour the same parameters were measured. Results: The changes in arterial diameter in the experimental and control group were 30.83 ± 10.43% and 40.00 ± 8.61%, respectively. The vein diameter decreased by 22.98 ± 10.08% in the experimental group compared to 49.05 ± 10.08% for the control group. Furthermore, the arterial flow change in the control group was 8.28 ± 2.10% compared to 1.16 ± 0.65% in the experimental group. In addition, the venous flow in the control group decreased by 9.27 ± 2.75% compared to 0.92 ± 0.56% in the experimental group. Both arterial and venous diameters and flows showed statistical significance between the experimental and control groups (p <.05). Conclusions: Our study demonstrated that pretreatment with botulinum toxin B led to significantly reduced change in vascular diameters and flows compared with the control group, supporting the anti-vasospastic effects of botulinum toxin B.