title: Caffeine impairs gastrointestinal function in newborn rats.
abstract: BACKGROUND
  Feeding intolerance is commonly documented in premature infants. Caffeine is routinely utilized for apnea of prematurity treatment and known to reduce the lower esophageal sphincter (LES) muscle tone, but the caffeine effect on the newborn gastrointestinal function is unknown. We hypothesized that caffeine impairs esophageal and gastrointestinal motor function. As such, we investigated the drug effect on the tissue's mechanical properties and the newborn rat's in vivo gastric emptying rate.
  
  
  METHODS
  The effects of caffeine on LES, gastric fundal and antrum, as well as ileal and colonic muscle force potential and relaxation response, were measured in newborn and adult rats. The caffeine-induced (10 mg/kg i.p.) newborn gastric emptying rate changes were evaluated following 3 h of fasting.
  
  
  RESULTS
  Caffeine relaxed the precontracted LES and fundal muscle (P < 0.01), reduced the gastric and intestinal muscle contraction (P < 0.01), and delayed the pups' gastric emptying time (P < 0.01). The caffeine-induced muscle relaxant effect was independent of age and mediated via ryanodine receptors.
  
  
  CONCLUSIONS
  Caffeine administration to newborn rats at a dose comparable to the one therapeutically used for preterm neonates impairs LES and gastrointestinal motor function. Further clinical investigation on the possible contribution of caffeine to neonatal feeding intolerance is warranted.
authors: Physiology & Experimental Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors: Christopher
authors: C
authors: Welsh
authors: Physiology & Experimental Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors: Jingyi
authors: J
authors: Pan
authors: 1] Physiology & Experimental Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada [2] Department of Paediatrics and Physiology, University of Toronto, Toronto, Ontario, Canada.
authors: Jaques
authors: J
authors: Belik
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002110:Caffeine / Q000009:adverse effects* / Q000737:chemistry; D000697:Central Nervous System Stimulants / Q000009:adverse effects / Q000737:chemistry; D003106:Colon / Q000187:drug effects; D004195:Disease Models, Animal; D004947:Esophagus / Q000187:drug effects* / Q000378:metabolism; D005746:Gastric Emptying / Q000187:drug effects*; D005764:Gastroesophageal Reflux; D041981:Gastrointestinal Tract / Q000187:drug effects* / Q000378:metabolism; D007082:Ileum / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D051381:Rats; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D013314:Stress, Mechanical
chemical_list: D000697:Central Nervous System Stimulants; D019837:Ryanodine Receptor Calcium Release Channel; D002110:Caffeine