|
|
||||||||
Correspondence to:
Charles J. Schultz
Combined lipase deficiency (cld) is a recessive mutation in mice that causes a severe lack of lipoprotein lipase (LPL) and hepatic lipase (HL) activities, hyperlipemia, and death within 3 days after birth. Earlier studies showed that inactive LPL and HL were synthesized by cld/cld tissues and that LPL synthesized by cld/cld brown adipocytes was retained in their ER. We report here a study of HL in liver, adrenal, and plasma of normal newborn and cld/cld mice. Immunofluorescence studies showed HL was present in extracellular space, but not in cells, in liver and adrenal of both normal and cld/cld mice. When protein secretion was blocked with monensin, HL was retained intracellularly in liver cell cultures and in incubated adrenal tissues of both groups of mice. These findings demonstrated that HL was synthesized and secreted by liver and adrenal cells in normal newborn and cld/cld mice. HL activities in liver, adrenal, and plasma in cld/cld mice were very low, <8% of that in normal newborn mice, indicating that HL synthesized and secreted by cld/cld cells was inactive. Livers of both normal newborn and cld/cld mice synthesized LPL, but the level of LPL activity in cld/cld liver was very low, <9% of that in normal liver. Immunofluorescence studies showed that LPL was present intracellularly in liver of cld/cld mice, indicating that LPL was synthesized but not secreted by cld/cld liver cells. Immunofluorescent LPL was not found in normal newborn liver cells unless the cells were treated with monensin, thus demonstrating that normal liver cells synthesized and secreted LPL. Livers of both groups of mice contained an unidentified alkaline lipase activity which accounted for 34;54% of alkaline lipase activity in normal and 65% of that in cld/cld livers.
Our findings indicate that liver and adrenal cells synthesized and secreted HL in both normal newborn and cld/cld mice, but the lipase was inactive in cld/cld mice. That cld/cld liver cells secreted inactive HL while retaining inactive LPL indicates that these closely related lipases were processed differently.Schultz, C. J., E. J. Blanchette-Mackie, and R. O. Scow. Adrenal and liver in normal and cld/cld mice synthesize and secrete hepatic lipase, but the lipase is inactive in cld/cld mice. J. Lipid Res. 2000. 41: 214;225.
Supplementary key words:
lipoprotein lipase, combined lipase deficiency, immunofluorescence microscopy, newborn mice
Copyright © 2000 by Lipid Research, Inc.
Original Article
Adrenal and liver in normal and cld/cld mice synthesize and secrete hepatic lipase, but the lipase is inactive in cld/cld mice
Charles J. Schultza,
E. Joan Blanchette-Mackieb, and
Robert O. Scowa
a Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
b Laboratory of Cell Biochemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
H. L. Dichek, N. Agrawal, N. E. Andaloussi, and K. Qian Attenuated corticosterone response to chronic ACTH stimulation in hepatic lipase-deficient mice: evidence for a role for hepatic lipase in adrenal physiology Am J Physiol Endocrinol Metab, May 1, 2006; 290(5): E908 - E915. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Galan, J. Peinado-Onsurbe, J. Julve, D. Ricart-Jane, M. Q. Robert, M. Llobera, and I. Ramirez Inactive hepatic lipase in rat plasma J. Lipid Res., December 1, 2003; 44(12): 2250 - 2256. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Gonzalez-Navarro, Z. Nong, L. Freeman, A. Bensadoun, K. Peterson, and S. Santamarina-Fojo Identification of mouse and human macrophages as a site of synthesis of hepatic lipase J. Lipid Res., May 1, 2002; 43(5): 671 - 675. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. L. Wade, R. A. Van Andel, S. G. Rice, C. L. Banka, and C. A. Dyer Hepatic Lipase Deficiency Attenuates Mouse Ovarian Progesterone Production Leading to Decreased Ovulation and Reduced Litter Size Biol Reprod, April 1, 2002; 66(4): 1076 - 1082. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. Boedeker, M. H. Doolittle, and A. L. White Differential effect of combined lipase deficiency (cld/cld) on human hepatic lipase and lipoprotein lipase secretion J. Lipid Res., November 1, 2001; 42(11): 1858 - 1864. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Journal of Biological Chemistry |
| Molecular and Cellular Proteomics | ASBMB Today |