title: Caffeine Inhibits Fluid Secretion by Interlobular Ducts From Guinea Pig Pancreas.
abstract: Caffeine is contained in coffee, tea, and numerous beverages and foods. We examined the direct effects of caffeine on the physiological function of pancreatic duct cells by using interlobular duct segments isolated from guinea pig pancreas.
  
  
  
  The rate of fluid secretion was continuously measured by monitoring the luminal volume of isolated duct segments. Changes in intracellular Ca concentration ([Ca]i) were estimated by microfluorometry in ducts loaded with Fura-2.
  
  
  
  Both secretin-stimulated and acetylcholine (ACh)-stimulated fluid secretions were substantially and reversibly inhibited by relatively low concentrations of caffeine as low as 0.03 mM relevant to blood levels after ingestion of caffeine-containing beverages. Caffeine inhibited ACh-induced elevation of [Ca]i and secretin-induced fluctuation of [Ca]i. Caffeine abolished thapsigargin-induced intracellular Ca release but did not affect the entry of extracellular Ca. Caffeine (0.05 mM) abolished ethanol (1 mM)-induced fluid hypersecretion in secretin-stimulated pancreatic duct.
  
  
  
  Low concentrations of caffeine directly inhibit pancreatic ductal fluid secretion stimulated by secretin or ACh and also ethanol-induced fluid hypersecretion. The inhibition by caffeine seems to be mediated by the blockade of intracellular Ca mobilization. Daily intake of caffeine may reduce the volume of pancreatic juice secretion.
authors.affiliation: From the Department of Human Nutrition, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Mochimaru
authors.forename: Akiko
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Miyuki
authors.initials: M
authors.lastname: Nakakuki
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Ituka
authors.initials: I
authors.lastname: Taniguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishiguro
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D005765:Gastrointestinal Agents / Q000494:pharmacology; D006168:Guinea Pigs; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism; D010183:Pancreatic Ducts / Q000187:drug effects* / Q000378:metabolism; D010189:Pancreatic Juice / Q000187:drug effects* / Q000378:metabolism; D012633:Secretin / Q000494:pharmacology; D046509:Tissue Culture Techniques; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000697:Central Nervous System Stimulants; D005765:Gastrointestinal Agents; D014665:Vasodilator Agents; D012633:Secretin; D002110:Caffeine; D000109:Acetylcholine; D002118:Calcium