title: Sodium bicarbonate treatment prevents gastric emptying delay caused by acute exercise in awake rats.
abstract: Physical exercise, mainly after vigorous activity, may induce gastrointestinal dysmotility whose mechanisms are still unknown. We hypothesized that physical exercise and ensuing lactate-related acidemia alter gastrointestinal motor behavior. In the present study, we evaluated the effects of short-term exercise on gastric emptying rate in awake rats subjected to 15-min swimming sessions against a load equivalent to 5% of their body weight. After 0, 10, or 20 min of exercise testing, the rats were gavage fed with 1.5 ml of a liquid test meal (0.5 mg/ml of phenol red in 5% glucose solution) and euthanized 10 min postprandially to measure fractional gastric dye recovery. In addition to inducing acidemia and increasing blood lactate levels, acute exercise increased (P < 0.05) gastric retention. Such a phenomenon presented a positive correlation (P < 0.001) between blood lactate levels and fractional gastric dye recovery. Gastric retention and other acidbase-related changes were all prevented by NaHCO3 pretreatment. Additionally, exercise enhanced (P < 0.05) the marker's progression through the small intestine. In anesthetized rats, exercise increased (P < 0.05) gastric volume, measured by a balloon catheter in a barostat system. Compared with sedentary control rats, acute exercise also inhibited (P < 0.05) the contractility of gastric fundus strips in vitro. In conclusion, acute exercise delayed the gastric emptying of a liquid test meal by interfering with the acid-base balance.
authors.affiliation: Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil;
authors.forename: Moisés T B
authors.initials: MT
authors.lastname: Silva
authors.forename: Raimundo C
authors.initials: RC
authors.lastname: Palheta-Junior
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Sousa
authors.forename: Patrícia A
authors.initials: PA
authors.lastname: Fonseca-Magalhães
authors.forename: Willy
authors.initials: W
authors.lastname: Okoba
authors.forename: Caio P S
authors.initials: CP
authors.lastname: Campos
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Oliveira
authors.forename: Pedro J C
authors.initials: PJ
authors.lastname: Magalhães
authors.forename: Armenio A
authors.initials: AA
authors.lastname: Santos
mesh_terms: D000818:Animals; D005746:Gastric Emptying / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D010805:Physical Conditioning, Animal / Q000379:methods / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D017693:Sodium Bicarbonate / Q000494:pharmacology*; D013997:Time Factors; D016896:Treatment Outcome; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*
chemical_list: D017693:Sodium Bicarbonate
keywords: anaerobic exercise; gastric motility; metabolic acidosis; sodium bicarbonate; swimming