Experimental production of elevated serum folate in dogs with intestinal blind loops. II. Nature of bacterially produced folate coenzymes in blind loop fluid.

Jejunal and ileal blind loops were constructed in separate groups of dogs and the folate coenzymes present in these loops were investigated. Although only those dogs with high blind loops had appreciably elevated folate levels active for Lactobacillus casei but not Streptococcus faecalis, every blind loop appeared to contain four folate compounds--5-formyltetrahydrofolic acid, 5-methyltetrahydrofolic acid, tetrahydrofolic acid and a compound tentatively identified as 5-formyltetrahydrofolic triglutamate. Why increased levels of 5-methyltetrahydrofolate alone are present in the serum of dogs with a high blind loop is discussed.