Innervation of eccrine sweat glands

Abstract

In recent years it has been shown on the example of primate skin that in addition to abundant cholinergic innervation, the eccrine glands are also supplied by adrenergic fibers, containing catecholamines. The presence of an adrenergic component of the innervation is demonstrated on the plantar eccrine sweat glands of a number of rodents and the cat by the detection of monoamine oxidase in it. The myelin nerve trunks, the short unmyelinated varicose terminals in direct contact with the secretory cells, as well as the mitochondria of cells of the eccrine sweat glands are rich in monoamine oxidase. Specific and nonspecific cholinesterases are localized in the dense network of nerves in lacing the secretory portions of the glands; individual fibers accompany the excretory ducts. The acetylcholinesterase concentration is lower than the concentration of nonspecific cholinesterase. In rats with chemical sympathectomy, induced by four-week administration of 25 mg/kg guanethidine from the first day of birth, in which 99% of the neurons in the stellate ganglia die, the monoamine oxidase concentration in the myelin nerves and in the mitochondria of the secretory cells drops very sharply, and acetylcholinesterase disappears from the nerves surrounding the glands.