Salivary Secretion of Highly Concentrated Chromogranin a in Response to Noradrenaline and Acetylcholine in Isolated and Perfused Rat Submandibular Glands

Abstract

SUMMARY Chromogranin A (CgA) is a member of a family of highly acidic proteins, chromogranins, which are co‐stored in the adrenergic neurons and paraneurons and co‐released with adrenaline and noradrenaline (NAd) in response to adequate stimulation. The present study provides novel evidence that CgA‐like immunoreactivity (IR) is stored in the exocrine cells in the granular convoluted tubule, and is secreted into saliva by stimulation with NAd and acetylcholine (ACh) in the isolated and perfused rat submandibular gland. NAd at 1 μM produced maximum secretion of CgA‐like IR (<< 0.9 mM) and a marked increase in salivary flow. Further increases in NAd concentration (10 or 100 μM) yielded concentration‐dependent decreases in both responses. ACh at 1 μM produced maximum salivary flow and a slight elevation of CgA‐like IR secretion (6 μM); 100 μM ACh decreased the salivary flow but increased the CgA‐like IR secretion (0.6 mM). Electron microscopic examination showed vigorous compound exocytosis of secretory granules in the cells of the granular convoluted tubule when the submandibular gland was stimulated with 1 μM NAd. These results provide an experimental basis for the view that the salivary CgA‐like IR secretion may be a sensitive and quantitative index of the activity of the sympathetic nervous system innervating the gland.

Salivary alpha amylase not chromogranin A reflects sympathetic activity: exercise responses in elite male wheelchair athletes with or without cervical spinal cord injury

“…In addition to adrenaline, a number of studies report relationships between noradrenaline and suggested markers for SNS activity [3, 13]. Whilst noradrenaline was not measured in the present study, it is highly likely that the noradrenaline response was similarly blunted as the adrenaline response, as shown earlier for cervical SCI [39, 40].…”

“…It is also secreted from the submandibular gland following stimulation by noradrenaline and acetylcholine [13]. In response to acute exercise stress, sCgA shows a similar response to sAA [5, 14].…”

Occlusion and brain function: mastication as a prevention of cognitive dysfunction

“…Using a multi-tasking procedure to elicit laboratory stress, Scholey et al (105) recently reported that gum chewing improved alertness and reduced state anxiety, stress, and salivary cortisol. In addition, for subjects who are subjected to a loud unpleasant sound, simulated bruxing suppresses the production of salivary chromogranin A (106), a marker of mental stress that reflects sympathetic activity (107,108). Chewing or light clenching immediately after stress is applied effectively and quickly returns salivary cortisol to the resting level (109).…”

Catestatin and vasostatin concentrations in healthy dogs

“…Chromogranin A, an acidic glycoprotein that belongs to the Granin family, is stored in chromaffin granules and coreleased with catecholamines and neuroendocrine hormones from the adrenal medulla and sympathetic nerve endings when the sympathoadrenal-medullary system is activated [7, 8]. An active secretion of CgA into saliva in the submandibular gland has been found in humans [9], horses, and rats [10, 11]. Chromogranin A can be measured in saliva and blood in humans, pigs, cows, and dogs [4, 12–15].…”