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. 1969 Apr;112(2):203–209. doi: 10.1042/bj1120203

Clearing-factor lipase in adipose tissue. Distinction of different states of the enzyme and the possible role of the fat cell in the maintenance of tissue activity

V J Cunningham 1, D S Robinson 1
PMCID: PMC1187693  PMID: 4308292

Abstract

1. Incubation of intact epididymal adipose tissue from fed rats at 37° in an albumin solution at pH7·4 in vitro results in rapid loss of clearing-factor lipase activity until a low activity, stable to prolonged incubation, is attained. The clearing-factor lipase activity of intact tissue from starved rats, which is initially much less than that of tissue from fed rats, is mainly stable to incubation at 37°. 2. Much of the clearing-factor lipase activity of intact epididymal adipose tissue from fed rats is inactivated by collagenase. The enzyme activity of intact tissue from starved rats is not inactivated by collagenase. 3. The clearing-factor lipase activity of fat cells isolated from the epididymal adipose tissue of fed rats is stable to prolonged incubation at 37°. It represents only a small proportion of the total activity of the intact tissue. In starved rats, the isolated fat cells contain a much higher proportion of the activity of the intact tissue. Their activity is also stable at 37°. 4. Incubation of isolated fat cells in a serum-based medium leads to a progressive rise in clearing-factor lipase activity. Actinomycin increases the extent of this rise in activity. No rise in clearing-factor lipase activity occurs when stromal-vascular cells isolated from epididymal adipose tissue are incubated in the medium. 5. The findings indicate that less than 20% of the activity of intact adipose tissue from fed rats is retained when fat cells are isolated from the tissue by collagenase treatment. The activity that is lost could be that which normally functions in the uptake of triglyceride fatty acids by the tissue.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. FREDRICKSON D. S., GORDON R. S., Jr Transport of fatty acids. Physiol Rev. 1958 Oct;38(4):585–630. doi: 10.1152/physrev.1958.38.4.585. [DOI] [PubMed] [Google Scholar]
  2. HOLLENBERG C. H. Effect of nutrition on activity and release of lipase from rat adipose tissue. Am J Physiol. 1959 Sep;197:667–670. doi: 10.1152/ajplegacy.1959.197.3.667. [DOI] [PubMed] [Google Scholar]
  3. Ho S. J., Ho R. J., Meng H. C. Comparison of heparin-released and epinephrine-sensitive lipases in rat adipose tissue. Am J Physiol. 1967 Feb;212(2):284–290. doi: 10.1152/ajplegacy.1967.212.2.284. [DOI] [PubMed] [Google Scholar]
  4. KELLEY T. F. IMPROVED METHOD FOR MICROTITRATION OF FATTY ACIDS. Anal Chem. 1965 Jul;37:1078–1079. doi: 10.1021/ac60227a044. [DOI] [PubMed] [Google Scholar]
  5. PAV J., WENKEOVA J. Significance of adipose tissue lipoprotein lipase. Nature. 1960 Mar 26;185:926–927. doi: 10.1038/185926a0. [DOI] [PubMed] [Google Scholar]
  6. Pokrajac N., Lossow W. J., Chaikoff I. L. The effect of nutritional state on lipoprotein lipase activity in isolated rat adipose tissue cells. Biochim Biophys Acta. 1967 May 16;139(1):123–132. doi: 10.1016/0005-2744(67)90118-0. [DOI] [PubMed] [Google Scholar]
  7. ROBINSON D. S. THE CLEARING FACTOR LIPASE AND ITS ACTION IN THE TRANSPORT OF FATTY ACIDS BETWEEN THE BLOOD AND TISSUES. Adv Lipid Res. 1963;1:133–182. doi: 10.1016/b978-1-4831-9937-5.50010-7. [DOI] [PubMed] [Google Scholar]
  8. RODBELL M. LOCALIZATION OF LIPOPROTEIN LIPASE IN FAT CELLS OF RAT ADIPOSE TISSUE. J Biol Chem. 1964 Mar;239:753–755. [PubMed] [Google Scholar]
  9. RODBELL M. METABOLISM OF ISOLATED FAT CELLS. I. EFFECTS OF HORMONES ON GLUCOSE METABOLISM AND LIPOLYSIS. J Biol Chem. 1964 Feb;239:375–380. [PubMed] [Google Scholar]
  10. Salaman M. R., Robinson D. S. Clearing-factor lipase in adipose tissue. A medium in which the enzyme activity of tissue from starved rats increases in vitro. Biochem J. 1966 Jun;99(3):640–647. doi: 10.1042/bj0990640. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Wing D. R., Robinson D. S. Clearing-factor lipase in adipose tissue. Studies with puromycin and actinomycin. Biochem J. 1968 Feb;106(3):667–676. doi: 10.1042/bj1060667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Wing D. R., Salaman M. R., Robinson D. S. Clearing-factor lipase in adipose tissue. Factors influencing the increase in enzyme activity produced on incubation of tissue from starved rats in vitro. Biochem J. 1966 Jun;99(3):648–656. doi: 10.1042/bj0990648. [DOI] [PMC free article] [PubMed] [Google Scholar]

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