Endoscopic measurement of gastric corpus mucosal blood flow in conscious dogs.

This study reports the feasibility of applying the hydrogen gas clearance technique with 3% hydrogen in air and platinum contact electrode to measure corpus mucosal blood flow in conscious dogs. Three percent hydrogen in air is safe and does not produce hypoxia during inhalation. A specially prepared, six-inch polyvinyl chloride pipe was used as a bite-block. The platinum contact electrode, attached to (but not within) a soft rubber suction cup, was passed into the stomach with the aid of a gastroscope. Because of gastric contractions, low, continuous suction was required to maintain the electrode in contact with the corpus mucosa. Stable baseline corpus mucosal blood flow measurements were obtained on control and experimental days in five of 10 dogs. In these five dogs during 2 micrograms/kg/hr pentagastrin infusion, which induced submaximal acid secretion, corpus mucosal blood flow and gastric acid output were increased significantly (P less than 0.05) by 26 +/- 4% and 238 +/- 79%, respectively. These increases were similar to those previously observed in anesthetized rats, cats, rabbits, and dogs. In an anesthetized rat study, the measurement of corpus mucosal blood flow was found to be unaffected by the low continuous suction. Since the use of 3% hydrogen in air is safe, the technique deserves to be further evaluated in human studies.