Theory of Gastric Ventilation: Effects of Hyperoxia, Hypoxia, and Hyperbaric Exposure in the Rat

Abstract

We previously described gastric ventilation, a phenomenon in which hypercapnia stimulates gastric acid secretion. In the present study, we tested the effects of the following on gastric acid secretion: normobaric normoxia (NN) hypobaric hypoxia (hh), normobaric hypoxia (Nh), hyperbaric hyperoxia (HH), hyperbaric hypercapnia (HC), and hyperbaric normoxia (HN). Two rats implanted with gastric catheters have completed hypobaric experiments; 1 completed hyperbaric experiments. In hypobaric experiments, minute ventilation (VE) was 74.4 ± 5.7 ml/min at NN (mean ± SE) and increased as expected to 81.6 ± 35.5 ml/min at hh and 76.1 ± 8.6 ml/min at Nh; pH appeared minimally affected: 3.7 ± 0.2 at NN, 3.8 ± 0.3 at hh, and 3.7 ± 0.4 at Nh. Hyperbaric exposures appeared to stimulate gastric acid secretion, though in the rat tested, the response appeared delayed until the following air period: pH was 4.52 at NN, 4.5 at HH, 3.94 at NN, 3.81 at HC, 3.64 at NN, 3.66 at HN, and 3.64 at the final NN. This suggests that gastric acid secretion responds to environmental stimuli, an important health consideration for those who routinely dive and who tend to retain CO2 while diving. Funded by ONR.

Document Details

Document Type
Pub Defense Publication
Publication Date
Apr 01, 2013
Source ID
10.1096/fasebj.27.1_supplement.716.3

Entities

People

  • Carol S. Landon
  • Heather E. Held
  • Jay B. Dean

Organizations

  • Office of Naval Research
  • University of South Florida

Tags

Readers

  • Analytical Mechanics
  • Auditory Neuroscience/Auditory Physiology.
  • Cardiovascular Physiology