Degradation of Particulate Lipid by the Large-Granule Fraction of Rat Liver

Abstract

Summary

Radiolabeled participate lipid administered intravenously was cleared from the circulation and localized primarily within the liver. The phagocytized ¹³¹I-triglyceride was degraded with the subsequent release of free ¹³¹I from the liver. Incubation of the ¹³¹I-triglyceride emulsion in vitro with different hepatic subcellular fractions revealed that the lysosome rich large-granule fraction contained the highest specific deiodinative activity. This observation coupled with the findings on latency of activation and an acid pH optimum, support the concept that the lysosomes are critically involved in the degradation of the particulate phagocytized lipid in the liver.

This study was supported, in part, by the Grant Nos. GM-21447andCA-16011.

Dr. R. P. Cornell is presently Assistant Professor, Division of Sciences, Northeast Missouri State University, Kirksville, MO.

Please send reprint requests to Thomas M. Saba, Ph.D., Professor and Chairman, Department of Physiology, Albany Medical College, Albany, NY 12208.