Effects of colchicine and cycloheximide on the functional and non-functional lipoprotein lipase fractions of rat heart

J. Borensztajn*, M. S. Rone, T. Sandros

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

In response to food deprivation, total myocardial lipoprotein lipase activity increased gradually over a period of 9 h. Although lipoprotein lipase exists in a functional and non-functional form in the myocardium, most of the increase in activity occurred in the functional (heparin-releasable) lipoprotein lipase fraction. The administration of colchicine, while having no effect on the increase seen in total lipoprotein lipase activity, did inhibit the increase in the functional fraction, while at the same time, caused a marked rise in the activity of the non-functional (non-releasable) fraction. In rats injected with colchicine after a 24-h fast, total lipoprotein lipase activity was not affected, but activity levels in the functional fraction declined while that in the non-functional fraction increased. These results suggest that the functional lipoprotein lipase is constantly being formed in sites not readily accessible to heparin (presumably the myocardial cells) and transported to its site of action, the surface of the endothelial cells of the capillaries. Cycloheximide administration to rats starved for 24 h caused a decline in activity in both the functional (half-life of about 2 h) and the non-functional (half-life of about 4 h) lipoprotein lipase fractions. These results suggest that the functional and non-functional lipoprotein lipase fractions may correspond to two distinct enzyme species.

Original languageEnglish (US)
Pages (from-to)394-400
Number of pages7
JournalBiochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism
Volume398
Issue number3
DOIs
StatePublished - Sep 19 1975

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Endocrinology

Fingerprint

Dive into the research topics of 'Effects of colchicine and cycloheximide on the functional and non-functional lipoprotein lipase fractions of rat heart'. Together they form a unique fingerprint.

Cite this