Lipoprotein lipase-mediated sequestration of long-chain polyunsaturated triacylglycerols in serum LDL normal and hypothyroid rats

Neale Ridgway; Peter J. Dolphin

doi:10.1016/0005-2760(84)90239-X

Lipoprotein lipase-mediated sequestration of long-chain polyunsaturated triacylglycerols in serum LDL normal and hypothyroid rats

Neale Ridgway, Peter J. Dolphin

Medicine

Medicine

Research output: Contribution to journal › Article › peer-review

14 Citations (Scopus)

Abstract

Rat serum VLDL, unlike human, contains significant proportions of triacylglycerols with polyunsaturated C₂₀ and C₂₂ fatty acids. Hypothyroidism in this species is characterized by low levels of serum VLDL, the accumulation of LDL, elevated levels of lipoprotein lipase and depressed hepatic lipase activity. The hypothyroid rat thus represents an interesting model in which to study hepatic VLDL metabolism and the substrate specificity of lipoprotein lipase. This report shows that serum IDL and LDL in both euthyroid and hypothyroid rats contain progressively enhanced proportions of triacylglycerols with polyunsaturated C₂₀ and C₂₂ fatty acids when compared to VLDL. Hypothyroidism resulted in a decrease in the proportion of 22:06 fatty acid within the serum VLDL triacylglycerols when compared to euthyroid VLDL. Lipolysis of VLDL from euthyroid rats in vitro using the perfused rat heart system resulted in increases or sequestration o0f triacylglycerols containing long-chain polyunsaturated fatty acids within the IDL fraction similar to those seen in vivo. It is concluded that lipoprotein lipase-mediated hydrolysis of VLDL triacylglycerols and the conversion of VLDL to IDL and LDL in the rat results in a progressive sequestration of the longer-chain polyunsaturated triacylglycerol molecular species with the IDL and LDL.

Original language	English
Pages (from-to)	64-71
Number of pages	8
Journal	Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
Volume	796
Issue number	1
DOIs	https://doi.org/10.1016/0005-2760(84)90239-X
Publication status	Published - Oct 24 1984

Bibliographical note

Funding Information:
The authors are indebted to Dr. Carl Brecken-ridge for use of his gas chromatograph and for many useful discussions. We thank Drs. J-J. Myher and A. Kuksis for validating our fatty acid methyl ester identifications by capillary column gas chromatography, This study was supported by a Grant-in-Aid of Research from the Nova Scotia Heart Foundation. N.R. is the recipient of a Nova Scotia Heart Foundation Graduate Student traineeship.

ASJC Scopus Subject Areas

Biophysics
Biochemistry
Endocrinology

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10.1016/0005-2760(84)90239-X

Cite this

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title = "Lipoprotein lipase-mediated sequestration of long-chain polyunsaturated triacylglycerols in serum LDL normal and hypothyroid rats",

abstract = "Rat serum VLDL, unlike human, contains significant proportions of triacylglycerols with polyunsaturated C20 and C22 fatty acids. Hypothyroidism in this species is characterized by low levels of serum VLDL, the accumulation of LDL, elevated levels of lipoprotein lipase and depressed hepatic lipase activity. The hypothyroid rat thus represents an interesting model in which to study hepatic VLDL metabolism and the substrate specificity of lipoprotein lipase. This report shows that serum IDL and LDL in both euthyroid and hypothyroid rats contain progressively enhanced proportions of triacylglycerols with polyunsaturated C20 and C22 fatty acids when compared to VLDL. Hypothyroidism resulted in a decrease in the proportion of 22:06 fatty acid within the serum VLDL triacylglycerols when compared to euthyroid VLDL. Lipolysis of VLDL from euthyroid rats in vitro using the perfused rat heart system resulted in increases or sequestration o0f triacylglycerols containing long-chain polyunsaturated fatty acids within the IDL fraction similar to those seen in vivo. It is concluded that lipoprotein lipase-mediated hydrolysis of VLDL triacylglycerols and the conversion of VLDL to IDL and LDL in the rat results in a progressive sequestration of the longer-chain polyunsaturated triacylglycerol molecular species with the IDL and LDL.",

author = "Neale Ridgway and Dolphin, {Peter J.}",

note = "Funding Information: The authors are indebted to Dr. Carl Brecken-ridge for use of his gas chromatograph and for many useful discussions. We thank Drs. J-J. Myher and A. Kuksis for validating our fatty acid methyl ester identifications by capillary column gas chromatography, This study was supported by a Grant-in-Aid of Research from the Nova Scotia Heart Foundation. N.R. is the recipient of a Nova Scotia Heart Foundation Graduate Student traineeship.",

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doi = "10.1016/0005-2760(84)90239-X",

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AU - Ridgway, Neale

AU - Dolphin, Peter J.

N1 - Funding Information: The authors are indebted to Dr. Carl Brecken-ridge for use of his gas chromatograph and for many useful discussions. We thank Drs. J-J. Myher and A. Kuksis for validating our fatty acid methyl ester identifications by capillary column gas chromatography, This study was supported by a Grant-in-Aid of Research from the Nova Scotia Heart Foundation. N.R. is the recipient of a Nova Scotia Heart Foundation Graduate Student traineeship.

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N2 - Rat serum VLDL, unlike human, contains significant proportions of triacylglycerols with polyunsaturated C20 and C22 fatty acids. Hypothyroidism in this species is characterized by low levels of serum VLDL, the accumulation of LDL, elevated levels of lipoprotein lipase and depressed hepatic lipase activity. The hypothyroid rat thus represents an interesting model in which to study hepatic VLDL metabolism and the substrate specificity of lipoprotein lipase. This report shows that serum IDL and LDL in both euthyroid and hypothyroid rats contain progressively enhanced proportions of triacylglycerols with polyunsaturated C20 and C22 fatty acids when compared to VLDL. Hypothyroidism resulted in a decrease in the proportion of 22:06 fatty acid within the serum VLDL triacylglycerols when compared to euthyroid VLDL. Lipolysis of VLDL from euthyroid rats in vitro using the perfused rat heart system resulted in increases or sequestration o0f triacylglycerols containing long-chain polyunsaturated fatty acids within the IDL fraction similar to those seen in vivo. It is concluded that lipoprotein lipase-mediated hydrolysis of VLDL triacylglycerols and the conversion of VLDL to IDL and LDL in the rat results in a progressive sequestration of the longer-chain polyunsaturated triacylglycerol molecular species with the IDL and LDL.

AB - Rat serum VLDL, unlike human, contains significant proportions of triacylglycerols with polyunsaturated C20 and C22 fatty acids. Hypothyroidism in this species is characterized by low levels of serum VLDL, the accumulation of LDL, elevated levels of lipoprotein lipase and depressed hepatic lipase activity. The hypothyroid rat thus represents an interesting model in which to study hepatic VLDL metabolism and the substrate specificity of lipoprotein lipase. This report shows that serum IDL and LDL in both euthyroid and hypothyroid rats contain progressively enhanced proportions of triacylglycerols with polyunsaturated C20 and C22 fatty acids when compared to VLDL. Hypothyroidism resulted in a decrease in the proportion of 22:06 fatty acid within the serum VLDL triacylglycerols when compared to euthyroid VLDL. Lipolysis of VLDL from euthyroid rats in vitro using the perfused rat heart system resulted in increases or sequestration o0f triacylglycerols containing long-chain polyunsaturated fatty acids within the IDL fraction similar to those seen in vivo. It is concluded that lipoprotein lipase-mediated hydrolysis of VLDL triacylglycerols and the conversion of VLDL to IDL and LDL in the rat results in a progressive sequestration of the longer-chain polyunsaturated triacylglycerol molecular species with the IDL and LDL.

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Lipoprotein lipase-mediated sequestration of long-chain polyunsaturated triacylglycerols in serum LDL normal and hypothyroid rats

Abstract

Bibliographical note

ASJC Scopus Subject Areas

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