Possible mechanisms of the histochemical changes in the eccrine sweat glands during stress

In order to determine the relative role of neural factors in the regulation of the activity of the eccrine glands of rats during stress, the cytological and cytochemical criteria of their activity that we used earlier (glycogen, isoelectric point of the mitochondria, ratio of light and dark secretory cells) were applied to the eccrine glands of rats with chemical sympathectomy, induced for four-week administration of guanethidine. The level of sweat secretion and the histochemistry of monamine oxidase and cholinesterases were also investigated. It is found that after 2-h immobilization stress and in the case of chemical sympathectomy, the eccrine glands of rats exhibit practically complete similarity in the level of sweat secretion and in various histochemical indices of the activity of the glands and the state of the neuromediator systems. In comparison with the control, in these glands the sweat secretion is increased, there is no glycogen, the number of light secretory cells is increased and the number of dark ones decreased, the isoelectric point of the mitochondria is shifted by a unit of the pH scale in the alkaline direction, the monamine oxidase activity of the mitochondria of the secretory cells and the myelinated nerves is sharply reduced, and the anticholinesterase of the nerves that interlace the gland disappears. In the case of immobilization stress there is an apparent functional denervation of the eccrine glands.