Regional Distribution of Feline Esophageal Blood Flow

Abstract

The regional distribution of esophageal blood flow has not been studied in man or in an animal whose esophageal musculature is histologically similar. The cat is the only common laboratory animal whose esophagus, like man’s, contains both striated and smooth muscle in the muscularis externa. Nutrient blood flow to sequential mucosal and muscular segments of the feline esophagus was determined by use of the indicator fractionation technique and cardiac output studies. The smooth muscle of the muscularis externa received a slightly higher flow (21 ml per min per 100 g) than did striated muscle (17 ml per min per 100 g). This relative similarity of nutrient flow to these histologically different muscle types may reflect that they function in concert in the esophagus and are under similar neural control. Blood flow to 1 gram of esophageal mucosa and muscularis externa was similar. This distribution differs from that reported for the stomach and small bowel where 1 gram of mucosa receives a greater nutrient flow than does the muscularis externa. These distribution differences reflect functional and morphological differences between these parts of the gastrointestinal tract.