The Influence of Starvation and Refeeding on the Lipoprotein Lipase Activity of Skeletal Muscle and Adipose Tissue of Lean and Obese Zucker Rats

1983 ◽  
Vol 113 (6) ◽  
pp. 1150-1156 ◽  
Author(s):  
David W. Quig ◽  
Donald K. Layman ◽  
Peter J. Bechtel ◽  
L. Ross Hackler
1988 ◽  
Vol 249 (1) ◽  
pp. 45-49 ◽  
Author(s):  
I Dugail ◽  
A Quignard-Boulange ◽  
L Brigant ◽  
J Etienne ◽  
L Noe ◽  
...  

The aim of this study was to determine whether the increase in lipoprotein lipase activity displayed by the adipose tissue of obese (fa/fa) rats as compared with that of lean (Fa/fa) rats could be ascribed to a change in the content or in the catalytic properties of the enzyme. The question was addressed in rats of two ages: in 7-day-old suckling and in 30-day-old post-weaning pups. Inguinal fat-pads were removed surgically (7 days of age) or after killing (30 days of age), and acetone-extract powders were prepared. The relative quantity of enzyme was assessed by immunotitration using an antiserum raised in goat against purified lipoprotein lipase from rat adipose tissue. The results indicate that increases in enzyme activity in obese animals were strictly paralleled by increases in the amount of enzyme in suckling as well as in post-weaning pups. Moreover, the apparent Km values of lipoprotein lipase for its substrate triacylglycerol were identical in the two genotypes. In conclusion, the genotype-mediated increase in lipoprotein lipase activity in adipose tissue of obese Zucker rats was fully accounted for by an increase in the content of the enzyme. In addition, this work documents the mechanism of the increase in lipoprotein lipase activity during weaning, which is mediated mainly through changes in the adipose-tissue enzyme content.


1985 ◽  
Vol 38 (1) ◽  
pp. 131
Author(s):  
RK Tume ◽  
RF Thornton

The effects of species and plane of nutrition on serum activation of sheep adipose tissue lipoprotein lipase were studied over a range of substrate (triolein) concentrations. Serum, either from two species or from the same species on a different plane of nutrition, had differing effects on adipose tissue lipoprotein lipase activity. Serum from fed sheep was more effective than serum from fed rats in activating sheep adipose tissue lipoprotein lipase at low substrate concentrations. Serum taken from sheep on a restricted plane of nutrition, stimulated adipose tissue lipoprotein lipase activity at physiological substrate concentrations. The increased activity promoted by the factor(s) present in serum would ensure that those tissues (e.g. cardiac and skeletal muscle) which continue to synthesize lipoprotein lipase during fasting or nutritional restriction, are able to assimilate the relatively low amounts of circulating triacylglycerol.


Metabolism ◽  
1978 ◽  
Vol 27 (11) ◽  
pp. 1661-1671 ◽  
Author(s):  
Esko A. Nikkilä ◽  
Marja-Riitta Taskinen ◽  
Seppo Rehunen ◽  
Matti Härkönen

1994 ◽  
Vol 301 (2) ◽  
pp. 495-501 ◽  
Author(s):  
M Del Prado ◽  
T H Da Costa ◽  
D H Williamson

The effect of tri-iodothyronine (T3) administration on the utilization of dietary [14C]lipid by the mammary gland and adipose tissue of lactating and litter-removed rats was studied. (1) After an oral load of [1-14C]triolein, the lactating rats treated with T3 (50 micrograms/100 g body wt.) over 24 h showed an increase in 14CO2 production and a decrease in the total [14C]lipid transferred through the mammary gland that was paralleled by a decrease in tissue lipoprotein lipase (LPL) activity. (2) T3 administration decreased plasma prolactin in the lactating rats. Prolactin replacement in T3-treated rats restored LPL activity in the mammary gland, but did not increase the amount of dietary [14C]lipid transferred to the milk. (3) Chronic T3 administration (4 days) to lactating rats did not affect pup growth or the lipogenic rate in the mammary gland. (4) The administration of T3 to litter-removed rats inhibited the increase of LPL activity in white adipose tissue and decreased the accumulation of dietary [14C]lipid. This decrease was accompanied by increased 14CO2 production and [14C]lipid accumulation in skeletal muscle and heart. (5) It is concluded that hyperthyroidism depresses LPL activity in mammary gland and white adipose tissue, but not in muscle. The increased accumulation of [14C]lipid in muscle and increased production of 14CO2 in lactating and in litter-removed rats treated with T3 is in part due to the decreased total LPL in mammary gland and adipose tissue respectively, which are therefore less able to compete with muscle for the available plasma triacylglycerols.


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