scholarly journals Post-Heparin Triacylglycerol Lipases in Ovine Plasma

1988 ◽  
Vol 41 (2) ◽  
pp. 215
Author(s):  
RK Tume ◽  
RF Thornton ◽  
G WJohnson
Keyword(s):  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Lipolytic Activity ◽  
Hepatic Lipase ◽  
Significant Proportion ◽  
Lipolytic Enzyme ◽  
Free Fatty Acid Concentration ◽  
Lipoprotein Lipase Activity ◽  
Hepatic Lipase Activity ◽  
Heparin Plasma

Lipoprotein lipase and hepatic lipase have been shown to be present in the post-heparin plasma of sheep. Intravenous injection of heparin into sheep produced a rapid increase in the free fatty acid concentration and lipolytic enzyme activity of the plasma, both peaking within 5-15 min and then falling to pre-heparin levels within 30-60 min. Lipolytic activity was not detected in plasma before heparin treatment. Two distinct lipolytic activities were separated from the plasma by chromatography on heparin-Sepharose 6B. Lipoprotein lipase was identified on the basis that the lipolytic activity was dependent upon the addition of plasma, inhibited by 1M NaCI, and inhibited by a specific antiserum against lipoprotein lipase. The second lipolytic activity of plasma was identified as hepatic lipase, as it was not dependent upon plasma for activity, nor was it inhibited by 1M NaCI or antiserum against lipoprotein lipase. Its properties were identical to the lipase extracted from the liver of sheep. Lipoprotein-lipase activity, but not hepatic-lipase activity, was dependent upon the nutritional state of the sheep at the time of heparin injection. However, hepatic lipase comprised a significant proportion of the total lipolytic activity.

Growth hormone but not gonadal steroids influence lipoprotein lipase and hepatic lipase activity in hypophysectomized rats

1994 ◽  
Vol 140 (2) ◽  
pp. 203-209 ◽  
Author(s):  
K Vikman-Adolfsson ◽  
J Oscarsson ◽  
P Nilsson-Ehle ◽  
S Edén
Keyword(s):  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Hepatic Lipase ◽  
Gonadal Steroids ◽  
Female Rats ◽  
Male Rats ◽  
Lipoprotein Lipase Activity ◽  
Peripheral Tissues ◽  
Hepatic Lipase Activity ◽  
Hypophysectomized Rats

Abstract Lipoprotein lipase and hepatic lipase are involved in the degradation and cellular uptake of lipids in peripheral tissues and the liver. These enzymes seem to be influenced by gonadal steroids in the rat as well as in man. Since gonadal steroids have been shown to influence the secretory pattern of GH and since the effect of gonadal steroids on several metabolic functions may be dependent upon their effects on GH secretion, the present study was undertaken to investigate the developmental regulation of heparin-releasable lipoprotein lipase and hepatic lipase activities in female and male rats, and to study the effects of gonadal steroids and different modes of GH administration to hypophysectomized rats on these enzyme activities. Female and male Sprague–Dawley rats from 20 to 65 days of age were studied. Hypophysectomy was performed at 50 days of age and these rats were given replacement therapy with thyroxine and cortisone. Groups of hypophysectomized rats were treated with either oestradiol valerate (0·1 mg/kg per day) or testosterone enanthate (1 mg/kg per day). Bovine GH (1 mg/kg per day) was given to groups of hypophysectomized rats either by two daily subcutaneous injections or by continuous infusion using osmotic minipumps. Hormone treatment was given for 1 week. Lipoprotein lipase and hepatic lipase activities were measured in heparinized plasma. There was no difference in lipoprotein lipase activity between male and female rats at 20 to 45 days of age. Lipoprotein lipase activity decreased between 45 and 65 days of age in male rats but not in females and, at 65 days of age, lipoprotein lipase activity was higher in females compared with males. Hepatic lipase activity increased from 20 to 45 days of age in both female and male rats but at 45 and 65 days of age it was higher in female than in male rats. Hypophysectomy decreased lipoprotein lipase and hepatic lipase activity in female rats. Neither oestradiol nor testosterone treatment had any effects in hypophysectomized rats. Treatment with bovine GH increased both lipoprotein lipase and hepatic lipase activities irrespective of its mode of administration and these effects were not influenced by additional treatment with oestradiol or testosterone. After the last injection of GH, lipoprotein lipase activity was increased for 12 h. Hepatic lipase activity was increased at 2 and 4 h after the last GH injection but after 12 h the activity had decreased, indicating that the time-course for the effects of GH on lipoprotein lipase and hepatic lipase may be different. It is concluded that GH markedly influences post-heparin lipoprotein lipase and hepatic lipase activities. The lack of effects of gonadal steroids on these activities in hypophysectomized rats suggests that the gonadal steroids influence these lipases via their influence on GH release. Journal of Endocrinology (1994) 140, 203–209

POST HEPARIN PLASMA LIPOPROTEIN LIPASE ACTIVITY IN THYROID DISEASE

1968 ◽  
Vol 59 (4) ◽  
pp. 555-563 ◽  
Author(s):  
Knut Kirkeby ◽  
Inger Bjerkedal
Keyword(s):  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Significant Negative Correlation ◽  
Control Group ◽  
Lipoprotein Lipase Activity ◽  
Heparin Plasma ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients ◽  
High Triglyceride ◽  
Synthesis And Degradation

ABSTRACT Plasma post heparin lipoprotein lipase activity (LLA) has been studied in patients with hyper- and hypothyroidism and in rabbits made thyrotoxic with thyroxine. The hypothyroid patients had high triglyceride and low LLA values as compared with a control group of healthy subjects. Statistically highly significant negative correlation was found between the triglycerides in fasting patients and the post heparin LLA, indicating a causal relationship, possibly with disturbance of chylomicron degradation due to low LLA in the arterial wall. However, relatively low LLA values were also demonstrated in hyperthyroid patients as well as in rabbits following treatment with thyroxine for 3 weeks. A stimulating effect of the thyroid hormones on the synthesis and degradation of lipoprotein lipase may be a possible explanation for these apparently contradictory findings.

Plasma Lipoprotein Lipase Activity in Primary Type IV Hyperlipoproteinaemia

1972 ◽  
Vol 17 (6) ◽  
pp. 214-216 ◽  
Author(s):  
J. J. R. Weir ◽  
D. Cox ◽  
J. H. Moore ◽  
T. D. V. Lawrie
Keyword(s):  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Normal Subjects ◽  
Plasma Lipoprotein ◽  
Plasma Samples ◽  
Lipoprotein Lipase Activity ◽  
Type Iv ◽  
Normal Individuals ◽  
Heparin Plasma ◽  
Primary Type

Lipoprotein lipase activity has been measured in both pre- and post-heparin plasma samples from 6 patients with Primary Type IV hyperlipoproteinaemia and from 6 normal subjects. Post-heparin lipoprotein lipase activity was of the same order in plasma from both groups. Appreciable activity was, however, noted in plasma collected from the Type IV patients prior to administration of heparin. Lipase activity was minimal in such samples from normal individuals.

Two methods compared for measuring lipase activity in plasma after heparin administration.

1984 ◽  
Vol 30 (9) ◽  
pp. 1568-1570 ◽  
Author(s):  
C Ehnholm ◽  
E A Nikkilä ◽  
P Nilsson-Ehle
Keyword(s):  
Human Plasma ◽  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Hepatic Lipase ◽  
Gum Arabic ◽  
Systematic Difference ◽  
Enzymic Activity ◽  
Specific Substrate ◽  
Hepatic Lipase Activity ◽  
Heparin Administration

Abstract We compared two methods for the direct selective measurement of hepatic lipase and lipoprotein lipase activities in human plasma after intravenous administration of heparin. Except for the emulsifier (gum arabic vs lecithin), the two assay media for hepatic lipase are essentially similar. Results for hepatic lipase by these two assays correlate well (r = 0.99). The assays for lipoprotein lipase in the two procedures differ in the way that hepatic lipase activity is eliminated (immunological inhibition vs a specific substrate emulsion), and also with regard to the emulsifier. The substrate emulsion stabilized by gum arabic (immunological assay) consistently yielded about three times higher enzymic activity than the specific substrate stabilized by lecithin. Experiments in which purified enzymes were used demonstrated that this systematic difference can be accounted for by the different emulsifiers. The satisfactory correlation (r = 0.92) between the two lipoprotein lipase assays, however, demonstrates that they measure the same enzymic activity.

Lipolytic Activities in Post-Heparin Plasma in Man Measured with Different Substrate Emulsions

1978 ◽  
Vol 54 (2) ◽  
pp. 201-203
Author(s):  
B. Vessby ◽  
J. Boberg ◽  
H. Lithell
Keyword(s):  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Lipolytic Activity ◽  
Heparin Plasma ◽  
Post Heparin Lipolytic Activity

1. Post-heparin lipolytic activity in man has been studied by using a triglyceride substrate emulsion containing different emulsifiers. 2. The lipolytic activity measured was profoundly influenced by the type of emulsifier used in the substrate. Substrates stabilized by synthetic emulsifiers give higher lipolytic activity than Intralipid, which contains egg phospholipids as emulsifiers. This difference was solely explained by higher salt-resistant lipase activities found with emulsions containing synthetic emulsifiers. The salt-inhibited lipase activity, which has properties as a lipoprotein lipase, was not influenced by the type of emulsifier. 3. When used under specified conditions Intralipid seems to be virtually specific for extrahepatic post-heparin lipolytic activity.

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