Local effect of vasoactive intestinal polypeptide on human sweat-gland function.
Physiological significance of vasoactive intestinal polypeptide (VIP), a putative co-transmitter of the cholinergic neuron innervating sweat glands, was investigated by its local effect on drug-induced sweating. VIP, methacholine chloride (MCH), or VIP plus MCH dissolved in 0.1 ml of 0.9% NaCl solution to a specified concentration was injected intradermally at the center of a forearm test area of 15 cm2 and the sweat rate was recorded continuously by capacitance hygrometry. In a cool environment (Ta, 23 degrees C), VIP failed to cause sweat secretion, but increased the rate of MCH-induced sweating, most markedly at a concentration of 10(-5) g/ml, where the rise in local skin temperature was the greatest. On an area anesthetized by nerve block in a hot environment (Ta, 35 degrees C), the effect was less obvious and less consistent, indicating that the sweat-facilitatory effect of VIP is reduced under the condition of passive cutaneous vasodilation. It may be postulated that VIP plays a role in securing ample oxygen supply to functioning sweat glands, especially with a relatively high cutaneous vasoconstrictor tone.
Yamashita
Y
Y
Department of Physiology, Aichi Medical University, Japan.
Ogawa
T
T
Ohnishi
N
N
Imamura
R
R
Sugenoya
J
J
D000328:Adult; D005542:Forearm / Q000098:blood supply; D006801:Humans; D007271:Injections, Intradermal; D008297:Male; D016210:Methacholine Chloride; D008688:Methacholine Compounds / Q000494:pharmacology; D012881:Skin Temperature; D013545:Sweat Glands / Q000187:drug effects / Q000378:metabolism*; D013546:Sweating / Q000187:drug effects*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*; D014664:Vasodilation
D008688:Methacholine Compounds; D016210:Methacholine Chloride; D014660:Vasoactive Intestinal Peptide