Cellular Regulation of Amylase Secretion by the Parotid Gland

Understanding salivary fluid and protein secretion

“…This process is continuous in most cells (`constitutive' exocytosis), but it can be greatly accelerated following an appropriate cellular signal such as neural stimulation (`regulatory' exocytosis). In the three major salivary glands, parotid, submandibular and sublingual, exocytotic protein secretion is primarily controlled by the autonomic nervous system; sympathetic stimulation elicits protein release from parotid and submandibular gland acini, and parasympathetic stimulation elicits protein release from sublingual gland acini as well as some release from parotid acini (Quissell and Tabak, 1989; Spearman and Butcher, 1989). We will focus here on amylase secretion from rat parotid acinar cells as recent studies on this system are promoting a better understanding of the cellular events involved in salivary gland exocytosis.…”

Cholinergic regulation of amylase gene expression in the rat parotid gland. Inhibition by two distinct post-transcriptional mechanisms

“…Amylase is the most abundant protein present in rat parotid glands, accounting for up to 30 % of the total protein synthesized by this gland [1]. It is secreted together with other salivary proteins in response to a variety of neurotransmitters including noradrenaline, acetylcholine, substance P and vasoactive intestinal peptide [2][3][4]. Extensive studies on the participation of the different receptor types in regulating parotid secretion have shown that stimulation of the ,-adrenergic receptor represents the most efficient mechanism for inducing amylase or protein secretion [2,3].…”

“…It is secreted together with other salivary proteins in response to a variety of neurotransmitters including noradrenaline, acetylcholine, substance P and vasoactive intestinal peptide [2][3][4]. Extensive studies on the participation of the different receptor types in regulating parotid secretion have shown that stimulation of the ,-adrenergic receptor represents the most efficient mechanism for inducing amylase or protein secretion [2,3]. However, substantial secretion of amylase together with electrolytes can also be induced by activation of the muscarinic cholinergic receptor [4][5][6].…”