Figure 3. Rho-kinase-mediated MLC signalling in the cold-induced vasoconstriction.

Blood flow was measured using FLPI in anaesthetized mice following immersion of the ipsilateral hindpaw in cold (10 °C) water and the contralateral hindpaw remained untreated. (a) Representative blood flow trace of a cold-induced vascular response in WT mice pretreated with the selective Rho-kinase associated protein kinase inhibitor Y27632 or control (saline). (b) % Maximum change in hindpaw blood flow from baseline to 0–2 min following local cold treatment (maximum vasoconstriction) in WT mice pretreated with Y27632 (5 mg kg⁻¹, i.p., 30 min, n=6) and control (saline, i.p., 30 min, n=5). (c) Representative western blot of p-MLC at Ser19 of MLC and total MLC protein expression (uncropped blots are presented in Supplementary Figure 12). (d) Densitometric analysis of p-MLC and total MLC, normalized to β-actin (n=6). All error bars indicate s.e.m. **P<0.01, ***P<0.001 versus respective untreated, ^##P<0.01, ^###P<0.001 versus cold-treated hindpaw (analysis of variance, Bonferroni post hoc test).