Duck Pancreatic Acinar Cell as a Unique Model for Independent Cholinergic Stimulation–Secretion Coupling

Abstract

This paper investigated the role of acetylcholine (ACh) in physiological regulation of amylase secretion in avian exocrine pancreas. In the isolated duck pancreatic acini, ACh dose dependently stimulated amylase secretion, with a maximal effective concentration at 10 muM. The cAMP-mobilizing compounds forskolin, vasoactive intestinal peptide (VIP)/pituitary adenylate cyclase activating peptide (PACAP) receptor (VPAC) agonists PACAP-38 and PACAP-27 had no effect on the dose-response curve. ACh dose dependently induced increases in cytosolic Ca(2+) concentration ([Ca(2+)]( c )), with increasing concentrations transforming oscillations into plateau increases. Forskolin (10 muM), PACAP-38 (1 nM), PACAP-27 (1 nM), or VIP (10 nM) alone did not stimulate [Ca(2+)]( c ) increase; neither did they modulate ACh-induced oscillations, nor made ACh low concentration effective. These data indicate that ACh-stimulated zymogen secretion in duck pancreatic acinar cells is not subject to modulation from the cAMP signaling pathway; whereas it has been widely reported in the rodents that ACh-stimulated exocrine pancreatic secretion is significantly enhanced by cAMP-mobilizing agents. This makes the duck exocrine pancreas unique in that cholinergic stimulus-secretion coupling is not subject to cAMP regulation.

Morphometrical and histochemical foundation of pancreas and ductal system in white-eared bulbul (Pycnonotus leucotis)

“…The cells in the lumen of acini were observed simple flattened to low cuboidal cells which represent the starting of intercalated ducts,the interlobular ducts of pancreas in bulbul lined by simple cuboidal epithelia which changed to the columnar in main ducts,our results showed no difference with those of (16) in red common quail (Coturnix coturnix) but differ with him when observed the interlobular ducts lined by simple columnar epithelium,also our results not similar with (17) in duck whom noted the main ducts lined by simple to stratified columnar epithelium.…”

“…The ductal system of avian pancreas composed of intercalated, intralobular, interlobular duct and main excretory duct (pancreatic ducts), the epithelium which lined the ducts varied from simple cuboidal in intercalated and intralobular duct to tall columnar in interlobular duct, this information was noted by (16) in common Quail (coturnix coturnix ),while in early hatched goose (Anser anser) and duck the main excretory ducts were lined by simple to stratified columnar epithelium and these ducts have inner longitudinal and outer circular muscle layers surrounded externally by connective tissue (3,17).…”

The gut–brain axis in vertebrates: implications for food intake regulation

“…For instance, in amphibians, it has been reported that noradrenaline inhibits mucous secretion from the stomach of amphibians in vitro (Keogh et al, 1997) and that acetylcholine stimulates intestinal mucus secretion in the frog (Slaughter and Aiello, 1982). In birds, pancreatic secretion is stimulated by acetylcholine (Meacham and Johnson, 2003;Murai et al, 2000;Wang et al, 2009) and inhibited by adrenaline (Salido et al, 1985). Similarly, in fish, pancreatic secretion is enhanced by cholinergic agents and inhibited by adrenergic drugs (Milgram et al, 1991).…”

An essential role of NAD(P)H oxidase 2 in UVA-induced calcium oscillations in mast cells

“…Oscillatory increases in cytosolic calcium in different cell types including mast cells ensure that multiple and specific signals are encoded. Calcium oscillations could be induced by physiological concentrations of hormones and neurotransmitters, [1][2][3] bacterial cytotoxin or IgE, 4,5 but also by ultraviolet A irradiation (UVA, 320-400 nm). 6 Of the solar UV radiation, only UVA and UVB (290-320 nm) can reach the surface of the earth, of which about 95% is UVA.…”