title: Acute volaemic changes modify the gastroduodenal resistance to the flow of saline in anaesthetized dogs.
abstract: The effect of acute and sequential volaemic changes on the gastroduodenal flow of saline was assessed in 23 anaesthetized dogs following two different experimental protocols. Hypervolaemia, by i.v. infusion of saline, induced a gradual decrease on gastroduodenal flow which amounted to 76% below control values (P less than 0.001) when volaemic expansion attained 5% of body weight. This effect was volume dependent (17% increase on gastroduodenal flow per volume of infused saline equivalent to 0.5% of body weight, P less than 0.001), lasted for at least 90 minutes after infusion was completed and was also obtained by expanding previously bled animals. Hypovolaemia due to bleeding was followed by an increase on gastroduodenal flow of about 88% above control values (P less than 0.05) when haemorrhage was equal to 3% of body weight. This effect was also volume dependent (23% increase on gastroduodenal flow per volume of blood shed equivalent to a 0.5% of body weight, P less than 0.01) and was reversed after blood volume was restored. These modifications in the resistance of the gastroduodenal segment to the flow of liquid due to acute volaemic changes suggest that the extracellular fluid volume modulates the contractile activity of the gastroduodenal portion of the gut possibly to set a gastroduodenal handling of liquid adequate to cope with volaemic imbalances.
authors.affiliation: Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza Brazil.
authors.forename: A A
authors.initials: AA
authors.lastname: Santos
authors.forename: J
authors.initials: J
authors.lastname: Xavier-Neto
authors.forename: A T
authors.initials: AT
authors.lastname: Santiago Júnior
authors.forename: M A
authors.initials: MA
authors.lastname: Souza
authors.forename: A S
authors.initials: AS
authors.lastname: Martins
authors.forename: F
authors.initials: F
authors.lastname: Alzamora
authors.forename: F H
authors.initials: FH
authors.lastname: Rola
mesh_terms: D000818:Animals; D004064:Digestive System / Q000378:metabolism; D004068:Digestive System Physiological Phenomena; D004285:Dogs; D004386:Duodenum / Q000378:metabolism / Q000502:physiology; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D005753:Gastric Mucosa / Q000378:metabolism; D005767:Gastrointestinal Diseases / Q000378:metabolism / Q000503:physiopathology; D006470:Hemorrhage / Q000378:metabolism / Q000503:physiopathology; D007275:Injections, Intravenous; D007552:Isotonic Solutions; D008297:Male; D010953:Plasma Volume / Q000502:physiology*; D012965:Sodium Chloride / Q000008:administration & dosage / Q000378:metabolism; D013270:Stomach / Q000502:physiology
chemical_list: D007552:Isotonic Solutions; D012965:Sodium Chloride