Characteristics and function of ion channels in the superior lacrimal gland of the rabbit

Abstract

The secretion of the acqueous component of tears is dependent on the uneven distribution and nature of ion channels across lacrimal gland acinar cell membranes. Models to describe such secretion in lacrimal glands are based primarily on one species, the rat and have been developed in conjunction with observations of channel function and secretion from salivary and pancreatic exocrine glands, which are structurally similar to lacrimal glands. The applicability of these models to all species is unknown and furthermore none takes into account volume regulation mechanisms in these acinar cells. Therefore, the aim of this thesis was to broaden the basis for such models by identifying the major membrane ionic channels, characterising their mode of activation and determining their possible physiological roles in rabbit superior lacrimal gland acinar cells. Initially, a culture system for maintaining acinar cells for short and long terms was developed. This allowed for electrophysiological techniques to be employed to study the role of ionic channel activity in the secretion of the aqueous component of tears and cell volume regulation. This study demonstrates a number of unique findings and indicates that the models currently used to describe lacrimal gland secretion are not applicable to all species and need modifications which take into account cell volume regulation

Date of Award	1998
Original language	English