Anti-Muscarinic Acetylcholine Receptor-Like Immunoreactivity in Lacrimal Glands

Abstract

Lacrimal glands are extensively innervated by both the parasympathetic and sympathetic divisions of the autonomic nervous system. The neurotransmitters acetylcholine and norepinephrine are present in nerve fibers distributed among the secretory acini. Physiological studies using glands from a number of different species suggest that muscarinic acetylcholine receptors and both alpha and beta adrenergic receptors are present on the secretory acinar cells. There are no data, however, on the anatomic distribution of any neurotransmitter receptor in lacrimal glands. Given that the innervation density is sufficiently low so that it is unlikely that each acinar cell is directly innervated (see Walcott et al, this volume), it becomes even more important to determine the distribution of receptors in the glands in order to understand the control of lacrimal gland secretion.