scholarly journals Lipoprotein lipase activity in neonatal-rat liver cell types

1989 ◽  
Vol 259 (1) ◽  
pp. 159-166 ◽  
Author(s):  
F Burgaya ◽  
J Peinado ◽  
S Vilaró ◽  
M Llobera ◽  
I Ramírez
Keyword(s):  
Lipoprotein Lipase ◽  
Rat Liver ◽  
Lipase Activity ◽  
Cell Types ◽  
Total Activity ◽  
Time Dependent ◽  
Neonatal Rat ◽  
Lipoprotein Lipase Activity ◽  
Adult Rats ◽  
Fraction I

The lipoprotein lipase activity in the liver of neonatal (1 day old) rats was about 3 times that in the liver of adult rats. Perfusion of the neonatal liver with collagenase decreased the tissue-associated activity by 77%. When neonatal-rat liver cells were dispersed, hepatocyte-enriched (fraction I) and haemopoietic-cell-enriched (fraction II) populations were obtained. The lipoprotein lipase activity in fraction I was 7 times that in fraction II. On the basis of those activities and the proportion of both cell types in either fraction, it was estimated that hepatocytes contained most, if not all, the lipoprotein lipase activity detected in collagenase-perfused neonatal-rat livers. From those calculations it was also concluded that haemopoietic cells did not contain lipoprotein lipase activity. When the hepatocyte-enriched cell population was incubated at 25 degrees C for up to 3 h, a slow but progressive release of enzyme activity to the incubation medium was found. However, the total activity (cells + medium) did not significantly change through the incubation period. Cycloheximide produced a time-dependent decrease in the cell-associated activity. Heparin increased the amount of lipoprotein lipase activity released to the medium. Because the cell-associated activity was unchanged, heparin also produced a time-dependent increase in the total activity. In those cells incubated with heparin, cycloheximide did not affect the initial release of lipoprotein lipase activity to the medium, but blocked further release. The cell-associated activity was also decreased by the presence of cycloheximide in those cells. It is concluded that neonatal-rat hepatocytes synthesize active lipoprotein lipase.

Characterization of Lipoprotein Lipase Activity in the Newborn Rat Liver

Neonatology ◽  
1987 ◽  
Vol 51 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Manuel Reina ◽  
Senén Vilaró ◽  
Ignasi Ramirez ◽  
Miquel Llobera
Keyword(s):  
Lipoprotein Lipase ◽  
Rat Liver ◽  
Lipase Activity ◽  
Lipoprotein Lipase Activity ◽  
Newborn Rat

Uterine and adipose lipoprotein lipase activity in hormone-treated and pregnant rats

1983 ◽  
Vol 245 (2) ◽  
pp. E132-E137 ◽  
Author(s):  
J. M. Gray ◽  
M. R. Greenwood
Keyword(s):  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Estradiol Benzoate ◽  
Lipoprotein Lipase Activity ◽  
Adult Rats ◽  
Pregnant Rats ◽  
Retroperitoneal Adipose Tissue ◽  
First Time ◽  
Duration Of Pregnancy

We report for the first time the presence of lipoprotein lipase (LPL) activity in the uteri of adult rats. This uterine LPL activity was significantly elevated by administration of the estrogen, estradiol benzoate (EB), but not by treatment with the antiestrogen, nafoxidine. Both EB and nafoxidine, however, greatly reduce both parametrial and retroperitoneal adipose tissue LPL activities. Uterine LPL activity also changed as a function of the duration of pregnancy, increasing severalfold between days 14 and 18 and then decreasing by about 20% on day 21. These data suggest the existence of a hormone-dependent system of providing lipids for storage and/or utilization by metabolic and reproductive tissues as needed.

High liver lipoprotein lipase activity in hyperlipemic developing rats from undernourished pregnant mothers

1988 ◽  
Vol 8 (4) ◽  
pp. 309-314 ◽  
Author(s):  
D. López-Tejero ◽  
M. Llobera ◽  
E. Herrera
Keyword(s):  
Lipoprotein Lipase ◽  
Normal Control ◽  
Rat Liver ◽  
Lipase Activity ◽  
Hepatic Uptake ◽  
Lipoprotein Lipase Activity ◽  
Newborn Rat ◽  
Potential Relationship ◽  
High Liver ◽  
Pregnant Mothers

To study the potential relationship between circulating triacylglycerol (TAG) levels and lipoprotein lipase (LPL) activity in the newborn rat liver, pups from undernourished or normal control mothers were nursed by normal dams, and studied at 0, 1, 15 or 30 days of age. Plasma TAG levels and liver TAG concentration increased more in pups from undernourished mothers than they did in controls. At birth, liver LPL activity was similarly high in both groups but, whereas in controls it decreased progressively after birth, in pups from undernourished mothers it remained stable until 15 days of age. Results suggest that the hypertriglyceridemia present in pups from undernourished mothers may be responsible for the sustained high LPL activity in their liver which may enhance the hepatic uptake of circulating TAG.

scholarly journals Lipoprotein lipase activity of rat cardiac muscle. Changes in the enzyme activity during incubations of isolated cardiac-muscle cells in vitro

1980 ◽  
Vol 186 (3) ◽  
pp. 873-879 ◽  
Author(s):  
P Chohan ◽  
A Cryer
Keyword(s):  
Enzyme Activity ◽  
Cardiac Muscle ◽  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Muscle Cells ◽  
Total Activity ◽  
Lipoprotein Lipase Activity ◽  
Cardiac Muscle Cells ◽  
Intracellular Enzyme

1. Isolated cardiac-muscle cells from the hearts of adult rats were shown to retain a high amount of viability during 4 h of incubation when viability was assessed by Trypan Bue stain exclusion and intracellular enzyme leakage. 2. The cells also retained their ability to take up O2 and utilize added substrates over the period of incubation at both 25 and 30 degrees C. 3. When cells from the hearts of fed rats were incubated in a buffered-salts solution at pH 7.4 in the presence of amino acids and heparin, lipoprotein lipase activity in the medium increased progressively. 4. During these incubations the intracellular activity of the enzyme remained constant and the total activity of lipoprotein lipase in the system (cells plus medium) increased by 80% over the 4 h of incubation at 25 degrees C. 5. In the absence of heparin only low amounts of enzyme activity were detectable in the medium and the total lipoprotein lipase activity in the system remained constant. 6. The measurement of lipoprotein lipase activity in either fresh homogenates of the cells or in homogenates of acetone/diethyl ether-dried powders of the cells had no effect on the overall pattern of activity change during the incubations, although as reported previously the total activity detected with acetone/diethyl either-dried preparations was approx. 3-fold higher than with fresh cell homogenates. 7. The observations were compared with published data on lipoprotein lipase activity changes in neonatal heart cell cultures maintained in vitro.

scholarly journals Retention of glucose by N-linked oligosaccharide chains impedes expression of lipoprotein lipase activity: effect of castanospermine.

1992 ◽  
Vol 33 (9) ◽  
pp. 1343-1349
Author(s):  
H Masuno ◽  
EJ Blanchette-Mackie ◽  
CJ Schultz ◽  
AE Spaeth ◽  
RO Scow ◽  
...  
Keyword(s):  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Lipoprotein Lipase Activity ◽  
Activity Effect
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