Tags

Type your tag names separated by a space and hit enter

The esterification and modification of n-3 and n-6 polyunsaturated fatty acids by hepatocytes and liver microsomes of turbot (Scophthalmus maximus).

Abstract

The present study was undertaken to establish whether the formation of 22:6n-3 from 18:3n-3 and/or 20:5n-3 can occur in turbot liver and if this conversion is consistent with the operation of a Delta4 desaturase-independent pathway. At the same, time the effects of feeding a diet devoid of long chain polyunsaturated fatty acids (PUFA) on the patterns of esterification and modification of 18:3n-3, 20:5n-3 and 18:2n-6 by turbot hepatocytes and liver microsomes were examined. For this purpose, two groups of fish (25-30 g) were employed: one was fed a commercial diet containing fish oil (FO) and thus rich in long chain n-3 PUFA and the other was fed an experimental diet based on olive oil (OO). After 5 months of feeding, hepatocytes and liver microsomes isolated from individuals in the two groups of fish were incubated with [1-(14)C]-PUFA [either 18:3n-3, 20:5n-3 or 18:2n-6]. After 3 h of incubation, most radioactivity from all three radiolabelled substrates incorporated into lipids by hepatocytes and microsomes was recovered in the original substrate. The formation of desaturation products of n-3 radiolabelled substrates was higher in hepatocytes isolated from OO-fed than FO-fed fish. Small amounts of radiolabelled 22:6n-3 were formed from [1-(14)C]18:3n-3 and [1-(14)C]20:5n-3, but only by hepatocytes from fish fed OO, which also synthesised a small amount of radiolabelled 24:6n-3 from 14C-20:5n-3. Elongation products predominated over desaturation products in hepatic microsomes from both groups of fish studied, particularly in microsomes from fish fed FO. The results confirm that regardless of the long chain PUFA content of the diet, the production of 22:6n-3 in turbot liver from 18:3n-3 and/or 20:5n-3, and of 20:4n-6 from 18:2n-6, is very limited. The presence of radiolabelled 24:6n-3 in microsomes coupled with the absence of radiolabelled 22:6n-3 suggests that the formation of 22:6n-3 that does occur in turbot liver cells, may involve C24 intermediates and peroxisomal beta-oxidation.

Authors+Show Affiliations

Departamento de Biología Animal (U.D.I. Fisiología), Facultad de Biología, Universidad de La Laguna. 38206 La Laguna, Tenerife, Spain. covarodr@ull.esNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

12091101

Citation

Rodríguez, Covadonga, et al. "The Esterification and Modification of N-3 and N-6 Polyunsaturated Fatty Acids By Hepatocytes and Liver Microsomes of Turbot (Scophthalmus Maximus)." Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology, vol. 132, no. 3, 2002, pp. 559-70.
Rodríguez C, Pérez JA, Henderson RJ. The esterification and modification of n-3 and n-6 polyunsaturated fatty acids by hepatocytes and liver microsomes of turbot (Scophthalmus maximus). Comp Biochem Physiol B, Biochem Mol Biol. 2002;132(3):559-70.
Rodríguez, C., Pérez, J. A., & Henderson, R. J. (2002). The esterification and modification of n-3 and n-6 polyunsaturated fatty acids by hepatocytes and liver microsomes of turbot (Scophthalmus maximus). Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology, 132(3), pp. 559-70.
Rodríguez C, Pérez JA, Henderson RJ. The Esterification and Modification of N-3 and N-6 Polyunsaturated Fatty Acids By Hepatocytes and Liver Microsomes of Turbot (Scophthalmus Maximus). Comp Biochem Physiol B, Biochem Mol Biol. 2002;132(3):559-70. PubMed PMID: 12091101.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The esterification and modification of n-3 and n-6 polyunsaturated fatty acids by hepatocytes and liver microsomes of turbot (Scophthalmus maximus). AU - Rodríguez,Covadonga, AU - Pérez,José A, AU - Henderson,R James, PY - 2002/7/2/pubmed PY - 2004/2/5/medline PY - 2002/7/2/entrez SP - 559 EP - 70 JF - Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology JO - Comp. Biochem. Physiol. B, Biochem. Mol. Biol. VL - 132 IS - 3 N2 - The present study was undertaken to establish whether the formation of 22:6n-3 from 18:3n-3 and/or 20:5n-3 can occur in turbot liver and if this conversion is consistent with the operation of a Delta4 desaturase-independent pathway. At the same, time the effects of feeding a diet devoid of long chain polyunsaturated fatty acids (PUFA) on the patterns of esterification and modification of 18:3n-3, 20:5n-3 and 18:2n-6 by turbot hepatocytes and liver microsomes were examined. For this purpose, two groups of fish (25-30 g) were employed: one was fed a commercial diet containing fish oil (FO) and thus rich in long chain n-3 PUFA and the other was fed an experimental diet based on olive oil (OO). After 5 months of feeding, hepatocytes and liver microsomes isolated from individuals in the two groups of fish were incubated with [1-(14)C]-PUFA [either 18:3n-3, 20:5n-3 or 18:2n-6]. After 3 h of incubation, most radioactivity from all three radiolabelled substrates incorporated into lipids by hepatocytes and microsomes was recovered in the original substrate. The formation of desaturation products of n-3 radiolabelled substrates was higher in hepatocytes isolated from OO-fed than FO-fed fish. Small amounts of radiolabelled 22:6n-3 were formed from [1-(14)C]18:3n-3 and [1-(14)C]20:5n-3, but only by hepatocytes from fish fed OO, which also synthesised a small amount of radiolabelled 24:6n-3 from 14C-20:5n-3. Elongation products predominated over desaturation products in hepatic microsomes from both groups of fish studied, particularly in microsomes from fish fed FO. The results confirm that regardless of the long chain PUFA content of the diet, the production of 22:6n-3 in turbot liver from 18:3n-3 and/or 20:5n-3, and of 20:4n-6 from 18:2n-6, is very limited. The presence of radiolabelled 24:6n-3 in microsomes coupled with the absence of radiolabelled 22:6n-3 suggests that the formation of 22:6n-3 that does occur in turbot liver cells, may involve C24 intermediates and peroxisomal beta-oxidation. SN - 1096-4959 UR - https://www.unboundmedicine.com/medline/citation/12091101/The_esterification_and_modification_of_n_3_and_n_6_polyunsaturated_fatty_acids_by_hepatocytes_and_liver_microsomes_of_turbot__Scophthalmus_maximus__ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1096495902000726 DB - PRIME DP - Unbound Medicine ER -