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Activities of liver microsomal fatty acid desaturases in zinc-deficient rats force-fed diets with a coconut oil/safflower oil mixture of linseed oil.
Biol Trace Elem Res. 1995 Jun; 48(3):215-29.BT

Abstract

The present study was conducted to investigate the effect of zinc deficiency on fatty acid desaturation in rats fed two different types of dietary fat, a mixture of coconut oil and safflower oil (7:1, w/w, "coconut oil diet") or linseed oil ("linseed oil diet"). In order to ensure an adequate food intake, all rats were force-fed by gastric tube. Zinc deficiency caused statistical significant reduction of delta 9-desaturase activity in liver microsomes of rats fed coconut oil diet and tendencial reduction (p < 0.15) in rats fed linseed oil diet compared with control rats fed diets with the same type of fat. In agreement with this effect, zinc deficiency in the rats fed both types of dietary fat increased the ratio between total saturated and total monounsaturated fatty in liver phospholipids and liver microsomes. Zinc deficient rats on the coconut oil diet had unchanged delta 6-desaturase activity with linoleic acid as substrate and lowered activity with alpha-linolenic acid as substrate. In contrast, zinc deficient rats on the linseed oil diet had increased delta 6-desaturase activity with linoleic acid as substrate and unchanged activity with alpha-linolenic acid. Because linoleic acid is the main substrate for delta 6-desaturase in the rats fed coconut oil diet, and alpha-linolenic acid is the main substrate in the rats fed linseed oil diet, it is concluded that in vivo delta 6-desaturation was not changed by zinc deficiency in the rats fed both types of dietary fat. Activity of delta 5-desaturase was also not changed by zinc deficiency in the rats fed both dietary fats. Levels of fatty acids in liver phospholipids and microsomes derived by delta 4-, delta 5-, and delta 6-desaturation were not consistently changed by zinc deficiency in the rats fed both types of dietary fat. Thus, the enzyme studies and also fatty acid composition data of liver phospholipids and microsomes indicate that zinc deficiency does not considerably disturb desaturation of linoleic and alpha-linolenic acid. Therefore, it is suggested that similarities between deficiencies of zinc and essential fatty acids described in literature are not due to disturbed desaturation of linoleic acid in zinc deficiency. The present study also indicates that zinc deficiency enhances incorporation of eicosapentaenoic acid into phosphatidylcholine of rats fed diets with large amounts of n-3 polyunsaturated fatty acids.

Authors+Show Affiliations

Institut für Ernährungsphysiologie, Technischen Universität München-Weihenstephan, Freising, Germany.No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9398942

Citation

Eder, K, and M Kirchgessner. "Activities of Liver Microsomal Fatty Acid Desaturases in Zinc-deficient Rats Force-fed Diets With a Coconut Oil/safflower Oil Mixture of Linseed Oil." Biological Trace Element Research, vol. 48, no. 3, 1995, pp. 215-29.
Eder K, Kirchgessner M. Activities of liver microsomal fatty acid desaturases in zinc-deficient rats force-fed diets with a coconut oil/safflower oil mixture of linseed oil. Biol Trace Elem Res. 1995;48(3):215-29.
Eder, K., & Kirchgessner, M. (1995). Activities of liver microsomal fatty acid desaturases in zinc-deficient rats force-fed diets with a coconut oil/safflower oil mixture of linseed oil. Biological Trace Element Research, 48(3), 215-29.
Eder K, Kirchgessner M. Activities of Liver Microsomal Fatty Acid Desaturases in Zinc-deficient Rats Force-fed Diets With a Coconut Oil/safflower Oil Mixture of Linseed Oil. Biol Trace Elem Res. 1995;48(3):215-29. PubMed PMID: 9398942.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Activities of liver microsomal fatty acid desaturases in zinc-deficient rats force-fed diets with a coconut oil/safflower oil mixture of linseed oil. AU - Eder,K, AU - Kirchgessner,M, PY - 1995/6/1/pubmed PY - 1997/12/17/medline PY - 1995/6/1/entrez SP - 215 EP - 29 JF - Biological trace element research JO - Biol Trace Elem Res VL - 48 IS - 3 N2 - The present study was conducted to investigate the effect of zinc deficiency on fatty acid desaturation in rats fed two different types of dietary fat, a mixture of coconut oil and safflower oil (7:1, w/w, "coconut oil diet") or linseed oil ("linseed oil diet"). In order to ensure an adequate food intake, all rats were force-fed by gastric tube. Zinc deficiency caused statistical significant reduction of delta 9-desaturase activity in liver microsomes of rats fed coconut oil diet and tendencial reduction (p < 0.15) in rats fed linseed oil diet compared with control rats fed diets with the same type of fat. In agreement with this effect, zinc deficiency in the rats fed both types of dietary fat increased the ratio between total saturated and total monounsaturated fatty in liver phospholipids and liver microsomes. Zinc deficient rats on the coconut oil diet had unchanged delta 6-desaturase activity with linoleic acid as substrate and lowered activity with alpha-linolenic acid as substrate. In contrast, zinc deficient rats on the linseed oil diet had increased delta 6-desaturase activity with linoleic acid as substrate and unchanged activity with alpha-linolenic acid. Because linoleic acid is the main substrate for delta 6-desaturase in the rats fed coconut oil diet, and alpha-linolenic acid is the main substrate in the rats fed linseed oil diet, it is concluded that in vivo delta 6-desaturation was not changed by zinc deficiency in the rats fed both types of dietary fat. Activity of delta 5-desaturase was also not changed by zinc deficiency in the rats fed both dietary fats. Levels of fatty acids in liver phospholipids and microsomes derived by delta 4-, delta 5-, and delta 6-desaturation were not consistently changed by zinc deficiency in the rats fed both types of dietary fat. Thus, the enzyme studies and also fatty acid composition data of liver phospholipids and microsomes indicate that zinc deficiency does not considerably disturb desaturation of linoleic and alpha-linolenic acid. Therefore, it is suggested that similarities between deficiencies of zinc and essential fatty acids described in literature are not due to disturbed desaturation of linoleic acid in zinc deficiency. The present study also indicates that zinc deficiency enhances incorporation of eicosapentaenoic acid into phosphatidylcholine of rats fed diets with large amounts of n-3 polyunsaturated fatty acids. SN - 0163-4984 UR - https://www.unboundmedicine.com/medline/citation/9398942/Activities_of_liver_microsomal_fatty_acid_desaturases_in_zinc_deficient_rats_force_fed_diets_with_a_coconut_oil/safflower_oil_mixture_of_linseed_oil_ L2 - https://dx.doi.org/10.1007/BF02789404 DB - PRIME DP - Unbound Medicine ER -