Author:
Hamada Hiroyuki,Ishiguro Hiroshi,Yamamoto Akiko,Shimano-Futakuchi Sachiko,Ko Shigeru B. H.,Yoshikawa Toshiyuki,Goto Hidemi,Kitagawa Motoji,Hayakawa Tetsuo,Seo Yoshiteru,Naruse Satoru
Abstract
Ethanol strongly augments secretin-stimulated, but not acetylcholine (ACh)-stimulated, fluid secretion from pancreatic duct cells. To understand its mechanism of action, we examined the effect of short-chain n-alcohols on fluid secretion and intracellular Ca2+ concentration ([Ca2+]i) in guinea pig pancreatic ducts. Fluid secretion was measured by monitoring the luminal volume of isolated interlobular ducts. [Ca2+]i was estimated using fura-2 microfluorometry. Methanol and ethanol at 0.3–10 mM concentrations significantly augmented fluid secretion and induced a transient elevation of [Ca2+]i in secretin- or dibutyryl adenosine 3′,5′-cyclic monophosphate (DBcAMP)-stimulated ducts. However, they failed to affect fluid secretion and [Ca2+]i in unstimulated and ACh-stimulated ducts. In contrast, propanol and butanol at 0.3–10 mM concentrations significantly reduced fluid secretion and decreased [Ca2+]i in unstimulated ducts and in ducts stimulated with secretin, DBcAMP, or ACh. Both stimulatory and inhibitory effects of n-alcohols completely disappeared after their removal from the perfusate. Propanol and butanol inhibited the plateau phase, but not the initial peak, of [Ca2+]i response to ACh as well as the [Ca2+]i elevation induced by thapsigargin, suggesting that they inhibit Ca2+ influx. Removal of extracellular Ca2+ reduced [Ca2+]i in duct cells and completely abolished secretin-stimulated fluid secretion. In conclusion, there is a distinct cutoff point between ethanol (C2) and propanol (C3) in their effects on fluid secretion and [Ca2+]i in duct cells. Short-chain n-alcohols appear to affect pancreatic ductal fluid secretion by activating or inhibiting the plasma membrane Ca2+ channel.
Publisher
American Physiological Society
Reference31 articles.
1. Characteristics of fluid secretion from isolated rat pancreatic ducts stimulated with secretin and bombesin.
2. Regulation of fluid secretion and intracellular messengers in isolated rat pancreatic ducts by acetylcholine.
3. Case RM and Argent BE. Pancreatic duct cell secretion: control and mechanisms of transport. In: The Pancreas: Biology, Pathobiology and Disease (2nd ed.), edited by Go VLW, DiMagno EP, Gardner JD, Labenthal E, Reher HA, and Scheele GA. New York: Raven, 1993, p. 301–350.
4. Chin JH and Goldstein DB. Electron paramagnetic resonance studies of ethanol on membrane fluidity. Adv Exp Med Biol 85A: 111–122, 1977.
5. Effects of Ethanol on Ion Channels
Cited by
6 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献