The effects of autonomic drugs on sweat secretion in man
Chalmers, Theodore Moir
1) The sensitivity of sweat glands to intradermally injected acetylcholine (ACh) does not correlate well with spontaneous tendency to sweat.2) Sensitivity to ACh is lost after degeneration of the post- ganglionic nerve fibre. Preganglionic sympathectomy does not affect the response.3) After intradermal injections of ACh there is an unexplained delay of not less than 10 seconds before sweating is detectable.4) When injected intradermally atropine is taken up by the receptors more slowly than ACh. This relation- ship also applies to the inhibition of the action of nicotine by tetraethylammonium bromide.5) Release of ACh by the sweat nerve endings during reflex heating can be detected some minutes before sweating occurs. It may also occur in the absence of sweating at quite low environmental temperatures (18 - 20 °C.).6) In most persons intradermal adrenaline can also stimulate sweat secretion, although there is evidence from experiments with blocking agents that the inner- vation of the sweat glands is purely cholinergic.7) There is no evidence that in hyperhidrotic subjects the overactive palmar sweet glands are hyper - sensitive to ACh.8) Oral administration of ganglionic blocking agents of the methonium group is a promising method of treatment in hyperhidrosis.