抄録
The effect of acute ethanol intoxication on the intestinal absorption of B_<12> was studied in the rat. Diluted ethanol was given by a stomach tube in a single dose of 1.8ml per 100 gram body weight and ^<57>Co-B_<12>(cyanocobalamin) was given 4 hours later. The controls received an isocaloric glucose solution. It was found that the descent of the dose from the stomach was markedly delayed in the ethanol group, necessitating a direct, transserosal instillation of ^<57>Co-B_<12> in the small intestine. Physiological doses of ^<57>Co-B_<12> with or without rat intrinsic factor concentrate, as well as a supraphysiological dose were given into the midportion of the small intestine and absorption was measured from the radioactivity recovered in the intestine and organs. It was shown that IF-mediated absorption of B_<12> was markedly impaired in the ethanol treated rats. The mucosal absorption of IF-B_<12> measured by washing the lumen shortly after administration was also impaired, but to a lesser extent than that of the reduction in overall absorption. Non-IF mediated absorption of ^<57>Co-B_<12> Was not affected under these conditions regardless of the dose, neither was the tissue uptake following parenteral administration of ^<57>Co-B_<12> altered. It was concluded that ethanol impairs the active trasnport system for B12 involving the IF mechanism. (Received April 22,1972)
