Effect of chronic capsaicin and guanethidine treatment on skin blood flow of the rat.

Using a non-invasive laser Doppler velocimetry technique to measure skin blood flow in the rat skin, we have shown that chronic treatment with capsaicin inhibited the vasodilator response to a non-pathological, local heat (44 degrees C, 20 min duration) stimulus. However, sympathectomy, accomplished with chronic treatment of guanethidine, had no effect on this heat-induced vasodilation. Topical steroids have also been shown to inhibit this response thus, since the heat-dilator response appears from these results to be brought about by the release of sensory neuropeptides, the sensory neuron may be a target for topical steroid action.