Asymmetric Incorporation of Linoleic Acid-1-C14 and Stearic Acid-1-C14 Into Human Lymph Lecithins During Fat Absorption.

Abstract

Summary 1) Carboxyl-labelled linoleic and stearic acids were fed as free acids or as triglyceride esters to patients provided with thoracic duct fistula, and incorporation of these acids into various lipid classes of lymph was followed. 2) Linoleic acid was transported and incorporated into cholesterol esters, triglycerides, phospholipids and non-esterified fatty acids in the same manner as oleic and palmitic acids. Chyle triglycerides constitute the main transport form of both oleic, palmitic, linoleic and stearic acids in man. 3) When linoleic acid was fed, only about 4% of total lymph radioactivity was obtained in the phospholipids, but after feeding stearic acid about 20% of the activity was located in lymph phospholipids. 4) After isolation of lymph lecithins, there was a difference in position of the label in lecithins of lymph according to the fatty acid used. 5) After feeding linoleic acid-1-C¹⁴, approximately 75% of the label in lymph lecithins was localized in the alpha-position. However, with stearic acid-1-C¹⁴ about 80% of the label was found in the beta-position.