Mechanisms of Pronounced and Sustained Cutaneous Vasoconstriction During Cryotherapy

Abstract

Cryotherapy is a therapeutic technique using ice or cold water applied to the skin to reduce local blood flow. While beneficial, there are some side effects such as pronounced vasoconstriction and tissue ischemia that is sustained for hours post‐treatment. This study tested the hypothesis that sustained vasoconstriction is mediated by 1) Rho‐kinase and/or 2) elevated oxidative stress. 13 subjects were fitted with a commercially available cryotherapy unit with a water perfused bladder on the lateral portion of the right calf. 3 microdialysis membranes were threaded through the dermis underneath the bladder. One site received lactated ringers (CON), one received the Rho‐Kinase inhibitor Fasudil (FAS), and one received ascorbic acid (VitC). Skin temperature (SkT) and skin vascular conductance (SkVC) was measured at each site. Subjects had 0 °C water perfused through the cryotherapy bladder for 30 min, followed by passive rewarming for 2 hr. SkT fell from 34°C to 17.9°C cold water application across all sites. SkVC was reduced after 30 min of cooling with both FAS and VitC having attenuated vasoconstriction when compared to CON (P<0.05 for both). After 2 hr of passive rewarming SkVC was elevated at the FAS site where as it remained reduced CON and VitC sites (p<0.05). These findings indicate Rho‐kinase and oxidative stress contribute to pronounced vasoconstriction during cryotherapy and that the Rho‐kinase contributes to sustained vasoconstriction during the rewarming period post treatmentSupported by the National Institute of Biomedical Imaging and Bioengineering; R01EB015522 (Multi PI: K.D. Diller & R.M. Brothers).