Abstract
Badger plasma lipoproteins with density 1.006-1.063 g/ml have been subfractionated by means of affinity chromatography on a heparin-Sepharose column, using a modification of the method reported by Weisgraber and Mahley (1980. J. Lipid Res. 21: 316-325). These experiments have provided evidence for the presence of three lipoprotein subfractions hereinafter termed fractions I, II, and III. Fraction I was cholesteryl ester- and phospholipid-rich (ca. 35% and 30% of lipoprotein mass, respectively), and contained apoA-I as its prominent apolipoprotein constituent. In contrast, triglyceride-rich fractions II and III both exhibited a complex apolipoprotein pattern, including apoB-100, apoA-I, and apoE whose amino acid composition and NH2-terminal sequence in the badger are reported. However, fraction III appeared markedly enriched in apoE when compared to fraction II. On polyacrylamide gel electrophoresis, fraction I presented as a spectrum of particles with diameters in the 140-190 A range. In contrast, fraction II migrated as a single band with a diameter of approximately 200 A, and fraction III presented as a single band or a doublet with a diameter of 195-200 A. The respective plasma concentrations and chemical compositions of the three chromatographic fractions were determined at four different dates of the year (i.e., April, August, November, and January), each of which corresponded to a different endocrine status in the badger. Thus hypothyroidism appeared to be associated with an increase in the concentration of fraction I, while the lowering in summer of the plasma level of testosterone correlated well with an increase in the concentration of fraction II. At the same time, the respective proportions of hydrophobic lipids in this latter material modified with an increase of triglycerides. Finally, both the apolipoprotein pattern of fraction III, and the chronologic profile of the successive variations of its concentration, suggest that it could represent a metabolic precursor of fraction II. These results suggest that the respective metabolism of the lipoproteins constituting the three chromatographic fractions could be under control by thyroid and testis secretions, operating via a complex combined regulation of the activities of the enzymes and receptors involved in these metabolic processes.
Highlights
Badger plasma lipoproteinswith density 1.006-1.063g/ ml have been subfractionated by means of affinity chromatography on a heparin-Sepharose column, using a modification of the method reported by Weisgraber and Mahley
These results suggested that this animal species could be used as an original and valuable model for studies dealing with the endocrine regulation of plasma lipoprotein metabolism
A similar comment applies to the plasma lipoprotein profiles obtained by polyacrylamide gel electrophoresis according to the technique of Fruchart [21]
Summary
Badger plasma lipoproteinswith density 1.006-1.063g/ ml have been subfractionated by means of affinity chromatography on a heparin-Sepharose column, using a modification of the method reported by Weisgraber and Mahley The respective proportions of hydrophobic lipids in this latter material modified with an increase of triglycerides Both the apolipoprotein pattern of fraction 111, and the chronologic profile of the successive variations of its concentration, suggest that it could represent a metabolic precursor of fraction 11. Such observations have emphasized the importance of studies aimed at the elucidation of the interrelationships between endocrine activities on the one hand, and lipid metabolism and transport by plasma lipoproteins on the other In this context, we demonstrated in 1977 that the male European badger exhibited spontaneous seasonal variations of large amplitude in its plasma thyroxine and testosterone concentrations [1]. Since this date, successive studies in our laboratory have provided evidence for the presence, in Abbreviations: VLDL,very low density lipoproteins, d < 1.006 g / d ; LDL, low density lipoproteins,d 1.006-1.063 g / d , IDL,intermediate density lipoproteins, a part of LDL with d 1.006-1.019g/ml; HDL,high density lipoproteins, d 1.063-1.21 g / d , apo, apolipoprotein; EDTA, ethylene diamine tetraaceticacid; SDS,sodium dodecyl sulfate;HL,hepatic lipase
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
