Abstract
Summary
1. Data on the activity of choline oxidase, succinoxidase, tributyrinase and the enzymes concerned in the formation of methionine from choline, betaine or dimethylthetin and homocysteine are presented for liver tissue from the rat, mouse, guinea pig, rabbit, chicken, dog and man. 2. Analysis of 3 samples of fresh human liver indicate that man resembles rabbit and guinea pig in that choline oxidase activity and capacity to utilize choline to methylate homocysteine are low or absent. 3. Livers of all species examined were capable of utilizing betaine and its sulfur analog dimethylthetin to methylate homocysteine to form methionine. 4. Succinoxidase activity of 4 samples of fresh human liver were markedly lower than that of other species examined. Tributyrinase activity of two samples examined was of the same order of magnitude as that found in livers from the rat and the mouse.
Get full access to this article
View all access options for this article.