Absorption of water, electrolytes and volatile fatty acids in the rabbit caecal pouch

Abstract

1. A pouch was prepared from the distal half of the rabbit caecum and its absorptive function was investigated by perfusing an electrolyte solution comparable in composition to normal caecal fluid. 2. Pretreatment of the pouch with normal caecal contents resulted in net absorption of water, Na, Cl and volatile fatty acids (VFA). 3. Pretreatment of the pouch with experimental solution induced netsecretion of water and electrolytes, while net absorption of VFA was significantly reduced. 4. No histological damage was found in the pouch mucosa, but the number of mucopolysaccharide-containing cells was significantly increased. 5. These results indicate that in the absence of a normal microflora, specific conditions are developed in the rabbit caecal pouch, which may in some respects be comparable to the characteristics of the caecum of germ-free rodents.