Isolation and culture of submucosal gland cells.

Submucosal glands of the airways of higher mammalian species are complex structures that are located in the submucosal tissue of the tracheobronchial tree. The glands open onto the airways via ciliated ducts, which lead into the collecting ducts. Mucous and serous tubules lead from the collecting ducts and compose the glandular acini. The acini secrete primarily mucous glycoproteins, with the serous cells secreting mainly neutral mucins and the mucous cells, acidic mucins. Serous cells also participate in the transport of IgA and the secretion of lysozyme. Serous cells may also secrete electrolytes, thereby creating an osmotic gradient that may mediate water secretion. Evidence indicates that the cholinergic, adrenergic, and noncholinergic, nonadrenergic nervous systems may be important in the control of secretion by submucosal glands. The manner in which these systems interact to achieve control is still under investigation. In addition, a variety of local mediators, such as histamine and prostaglandins, influence submucosal glandular function. Studying the submucosal glandular physiology and pathophysiology has been difficult due to the cellular and structural complexity of the glands. Recently, methods have been developed to isolate and culture submucosal gland cells. The techniques seem to preserve cellular functions, and as such should prove to be valuable models for understanding these important secretory cells.