Pancreatic Extract and the Intestinal Uptake of Vitamin B₁₂

Abstract

Pancreatic extract (PE) reduced the uptake of rat intrinsic factor (IF)-bound ⁵⁷CoB₁₂ by perfused rat intestinal segments (p<0.02) as well as by isolated rat intestinal brush borders (p<0.01). The inhibition was concentration-dependent. Preincubation of the brush borders with PE reduced the subsequent uptake of ⁵⁷CoB₁₂-IF (p<0.05). The molecular weight of the ⁵⁷CoB₁₂-IF complex, as well as the uptake of the complex by isolated intestinal brush borders, was unchanged after prolonged preincubation with PE. PE also inhibited the uptake of glucose by perfused intestinal segments (p<0.01), but the morphology and disaccharidase activity (p>0.5) of the intestinal epithelium was unaltered. The results indicate that the inhibition may be due to interaction between the intestinal epithelium and PE.

Key-words:

• Gel filtration
• intestinal absorption
• intestinal mucosa
• intrinsic factor
• pancreatic disease
• pancreatic extract
• vitamin B₁₂
• vitamin B₁₂ deficiency