Analysis of sweating induced by VIP iontophoresis in human skin

In human skin transplanted to the back of three strains of immuno-deficient mice, the function of sweat glands of the human transplant was tested by i ntradermal application of pilocarpine, adrenaline, atropine + pilocarpine a nd VIP Sweat responses were observed in the former three substances, not VI P. Therefore, to re-examine the negative results on VIP, interactions of th e sudomotor axon reflex (AXR) with putative local mediators were studied by drug iontophoresis. The state of thermoregulation seems to modulate the ac tion of VIP as a possible co-transmitter facilitating AXR by raising skin t emperature. The underlying VIP-induced vasodilation may involve both sudomo tor and sensory axon reflex mechanisms. (C) 2000 Elsevier Science Ltd. All rights reserved.