title: Role of maternal tissue in the synthesis of polyunsaturated fatty acids in response to a lipid-deficient diet during pregnancy and lactation in rats.
abstract: During pregnancy and lactation, metabolic adaptations involve changes in expression of desaturases and elongases (Elovl2 and Elovl5) in the mammary gland and liver for the synthesis of long-chain polyunsaturated fatty acids (LC-PUFAs) such as arachidonic acid (AA) required for fetal and postnatal growth. Adipose tissue is a pool of LC-PUFAs. The response of adipose tissue for the synthesis of these fatty acids in a lipid-deficient diet of dams is unknown. The aim of this study was to explore the role of maternal tissue in the synthesis of LC-PUFAs in rats fed a low-lipid diet during pregnancy and lactation. Fatty acid composition (indicative of enzymatic activity) and gene expression of encoding enzymes for fatty acid synthesis were measured in liver, mammary gland and adipose tissue in rats fed a low-lipid diet. Gene expression of desaturases, elongases, fatty acid synthase (Fasn) and their regulator Srebf-1c was increased in the mammary gland, liver and adipose tissue of rats fed a low-lipid diet compared with rats from the adequate-lipid diet group throughout pregnancy and lactation. Genes with the highest (P<0.05) expression in the mammary gland, liver and adipose tissue were Elovl5 (1333%), Fads2 (490%) and Fasn (6608%), respectively, in a low-lipid diet than in adequate-lipid diet. The percentage of AA in the mammary gland was similar between the low-lipid diet and adequate-lipid diet groups during the second stage of pregnancy and during lactation. The percentage of monounsaturated and saturated fatty acids was significantly (P<0.05) increased throughout pregnancy and lactation in all tissues in rats fed a low-lipid diet than in rats fed an adequate-lipid diet. Results suggest that maternal metabolic adaptations used to compensate for lipid-deficient diet during pregnancy and lactation include increased expression of genes involved in LC-PUFAs synthesis in a stage- and tissue-specific manner and elevated lipogenic activity (saturated and monounsaturated fatty acid synthesis) of maternal tissues including adipose tissue.
authors.affiliation: Laboratorio de Biología Molecular, Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, IMSS, México City, Mexico. Electronic address: jwill6128@yahoo.com.mx.
authors.forename: Raúl Sánchez
authors.initials: RS
authors.lastname: González
authors.affiliation: Laboratorio de Biología Molecular, Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, IMSS, México City, Mexico. Electronic address: maricela.rodriguez.cruz@gmail.com.
authors.forename: Maricela
authors.initials: M
authors.lastname: Rodriguez-Cruz
authors.affiliation: Laboratorio de Biología Molecular, Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, IMSS, México City, Mexico. Electronic address: jormh@yahoo.com.mx.
authors.forename: Jorge
authors.initials: J
authors.lastname: Maldonado
authors.affiliation: Laboratorio de Biología Molecular, Unidad de Investigación Médica en Nutrición, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, IMSS, México City, Mexico.
authors.forename: Filiberto Jasso
authors.initials: FJ
authors.lastname: Saavedra
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D018752:Diet, Fat-Restricted; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D000081031:Fatty Acid Elongases; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D005260:Female; D005786:Gene Expression Regulation; D007774:Lactation / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000378:metabolism; D051780:Sterol Regulatory Element Binding Protein 1 / Q000378:metabolism*
chemical_list: D005231:Fatty Acids, Unsaturated; D051780:Sterol Regulatory Element Binding Protein 1; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C474452:delta 6-desaturase, rat; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases
keywords: Desaturases; Elongases; Long-chain polyunsaturated fatty acids; Pregnancy; Sterol-regulatory element binding factor