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Brief communications AJi

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Electron microscopy ofthe sweat glands from the hairy skin ofthe beagle D.W.K.COTTON,* P.VAN HASSELTf AND A.M.S.BERGERS* •Department of Dermatology, and tDepartment of General Neurophysioiogy, University of Nijmegen, The Netherlands Accepted for publication 14 March 1975

Recently Bell & Montagna (1972) published the results of a light histochemical study of sweat glands in the hairy skin of horses and dogs. They found that there was no demonstrable inncrvation of these glands in the dog. We have previously reported stimulation ofthe sweat glands on the hairy surface of the beagle by hypothalamic (Cotton, van Hasselt & Bergcrs, 1975) and peripheral nerve stimulation (Cotton & van Hasselt, 1972) but the stimulus levels were so high that we believe the effects to be unphysiological and secondary. The only effective physiological stimulus that we have found is copulation (Cotton et ah, 1975). Other authors have found that the kangaroo sweats during physical stress in a treadmill but not in response to heat (Dawson, Robertshow & Taylor, 1974)The data in the literature indicate that the sweat glands on the hairy surface ofthe dog are apocrine (Iwabuchi, 1967) and it is well known that the development of human apocrine glands is associated with sexual maturity (Zelickson, 1967). On the basis of these observations we have tentatively suggested (Cotton et ah, 1975) that these glands may have a pheromone (Mykytowycz & Goodrich, 1974) function in the dog. Since the structure of these glands has only been studied at the light histological level, we thought that it might be of interest to examine them under the electron microscope. We have sectioned a number of sweat glands obtained from the hairy skin of the dog and the following morphological details are apparent. In no section did we observe any nerve ending although these were readily discernable in human eccrine and dog foot pad preparations. Only two types of cells were visible, myoepithelial cells and secretory cells, containing many inclusions and bordered with microvilli (Cotton et al., 1975). The secretory cells contained the atypical mitochondria with amorphous matrix as described by Zelickson (1967) and sweat glands obtained from areas which had been stimulated to sweat by local injections of acetylcholine showed extended apical regions free of microvilli and inclusions. Consequently we conclude that these glands are apocrine and lack direct innervation. These conclusions, although not providing direct proof, are in accordance with the idea that the glands may serve a social communication function in addition to any as yet unclear, thermal regulation function.

REFERENCES BELL, M. & MONTAGNA, W. (1972) Innervation of sweat glands in horses and dogs. British Journal of Dermatology, 86, 160. COTTON, D.W.K. & VAN HASSELT, P. (1972) Sweating on the hairy surface of the beagle. Journal of Investigative Dermatology, 59, 313.

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COTTON, D.W.K., VAN HASSELT, P, & BERGERS, A . M . G . (1975) The nature of the swear glands in the hairy skin of the beagle. Dermatologica (in press). DAWSON, T J . , ROBERTSHOW, D. & TAYLOR, C.R. (1974) Sweating in the kangaroo: a cooling mechanism during exercise, but not in the heat. American Jottrnal of Physiology, 227, 474. IWABUCHi) T. (1967) General sweating on the hairy skin of the dog and its mechanisms. Journal of Investigative Dermatology, 49, 61. MYKYTOWYCZ, R . & GOODRICH, B.S. (1974) Skin glands as organs of communication in mammals. Journal of Investigative Dermatology, 62, 124. ZEUCKSON, A . S . (1967) Vltrastructure af normal and abnormal skin. Lea and Febiger, Philadelphia.

Hair fragment in the skin resembling larva migrans EERO A. LEHMUSKALLIO Department of Dermatology, University Central Hospital, Helsinki, Finland Accepted for publication 7 February 1975

Hair fragments penetrating the skin may produce a variety of different clinical pictures (Scott, 1957). One of the most peculiar of these resembles larva migrans (Yaffee, 1957; Schamberg, Park & Strauss, 1961; Ronchese, 1962).

FIGURE t . Hair fragment on medial side of the metatarsal area of the right foot. Correspondence address: Dr E.A.Lehmuskallio, Hevoshaantie 9 B 4, 01200 Vantaa 20, Finland,

Electron microscopy of the sweat glands from the hairy skin of the beagle.

348 Brief communications AJi (pf L'L/friJriti'iM'Ui j.L"iJ Electron microscopy ofthe sweat glands from the hairy skin ofthe beagle D.W.K.COTTON,*...
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