W. Hasan et al., The sweating apparatus in growth hormone deficiency, following treatment with r-hGH and in acromegaly, AUTON NEURO, 89(1-2), 2001, pp. 100-109
Adult growth hormone deficient patients are known to exhibit reduced sweati
ng and their ability to thermoregulate is diminished. Treatment of these pa
tients with recombinant human growth hormone (r-hGH) is claimed to reverse
these abnormalities. We have investigated this claim, as well as the mechan
ism underlying these altered sweating responses in GH-deficient patients as
part of a placebo-controlled study on the effects of 6-12 months r-hGH the
rapy. Skin biopsies were obtained from these subjects and changes in morpho
logy and innervation parameters for the eccrine sweat glands were examined.
These included histochemistry for acetylcholinesterase (AChE) and immunohi
stochemistry for the neuropeptide vasoactive intestinal polypeptide (VIP) a
nd for PGP9.5, a general neuronal marker. Sweat gland acinar size and peria
cinar innervation were measured by computerised image analysis. The patient
s underwent pilocarpine iontophoresis sweat rate tests and their serum insu
lin-like growth factor 1 (IGF 1) levels were assessed. Since active acromeg
aly involves excess GH secretion and hyperhidrosis, skin biopsies and sweat
tests were also carried out on a group of these patients, as well as on co
ntrol subjects.
We have demonstrated a sweating defect in adult GH-deficiency which is acco
mpanied by a reduction in AChE and VIP Levels in the nerve supply to sweat
glands. Following r-hGH therapy, an increase in AChE and VIP staining is se
en in the sudomotor nerves accompanied by restoration of sweat rates and se
rum IGF-1 levels. Hence, normalization of sweat gland function includes rec
overy of sudomotor synapse constituents. A trophic effect of GH on sweat gl
and epithelium and/or on the associated nerves is proposed, supported by th
e observation that in acromegaly the size of sweat gland acini and the dens
ity of innervation to the sweat glands was greater than in controls. (C) 20
01 Published by Elsevier Science B.V.