Abstract
Rony, Mortimer and Ivy 1 reported that the thoracic duct lymph of dogs that had fasted 2 to 14 days contains 250 to 1300 mg. of total fatty acids per 100 cc. lymph with an average value for 60 dogs of 630 mg. %. The total cholesterol content of these lymphs varied from 41 to 114 mg. %.
This work was undertaken to obtain further characteristics of the lipids of thoracic duct lymph in fasting. The lipid phosphorus content, the iodine number and the saponification value of the lymph lipids were examined.
The dogs fasted 4 to 7 days; the thoracic duct was cannulated under intravenous pentobarbital anesthesia and from 20 to 50 cc. of lymph were collected. This lymph was analyzed for lipid phosphorus with the Kuttner-Lichtenstein method, 2 for iodine number with the Hanus method, and for saponification value. Table I gives the results thus obtained on 12 dogs.
The values given in Table I for total fatty acids and total cholesterol are quoted from Rony, Mortimer and Ivy's paper. The values for “lecithin” are obtained by multiplying the lipid-P by 25. The saponification value represents the mg. KOH required to neutralize 1 gm. of the solids in the ether extract of lymph. The calculation of the unsaponifiable portion of the lymph fat was made on the basis of the assumption that all lipids present are C18 fatty acids.
It is known that, in fasting, lipids are excreted by the intestinal mucosa into the lumen of the bowel (Bloor and Sperry, etc.). Rony, Mortimer and Ivy found that in fasting the thoracic duct lymph fat consists chiefly of this fat, the major portion of which is reabsorbed by the intestinal mucosa and passed into the lacteals and thoracic duct.
Get full access to this article
View all access options for this article.