EFFECTS OF CONFINING INGESTED FLUID TO THE STOMACH ON WATER AND SALINE INTAKE IN THE RAT

Rats ingest more pure water in a 30-min test following 17 h of water d eprivation when the ingested water is confined to the stomach by a pyl oric cuff than when it is allowed to enter the duodenum (6). To test t he hypothesis that the reduced intake of water under normal drinking c onditions is due to postgastric cellular hydration, we allowed rats to ingest pure water or 0.15 M NaCl with the pylorus open and with it cl osed. When the pylorus was open, rats ingested more NaCl than water. W hen it was closed, they drank an equal volume of each solution. With t he cuff open, the rate of licking pure water began to decline within 3 min of the beginning of the test, an effect that did not occur when t he cuff was closed or with NaCl under either test condition. These dat a support the hypothesis that the intake of water during the first 30 min of access to it following a period of water deprivation is inhibit ed by the hydration of cells located postgastrically. Copyright (C) 19 96 Elsevier Science Inc.