Expression of genes participating in regulation of fatty acid and glucose utilization and energy metabolism in developing rat hearts

Abstract

Lavrentyev, Eduard N., Daifen He, and George A. Cook. Expression of genes participating in regulation of fatty acid and glucose utilization and energy metabolism in developing rat hearts. Am J Physiol Heart Circ Physiol 287: H2035-H2042, 2004. First published June 24, 2004 doi:10.1152/ajpheart.00372.2004.-The heart is a unique organ that can use several fuels for energy production. During development, the heart undergoes changes in fuel supply, and it must be able to respond to these changes. We have examined changes in the expression of several genes that regulate fuel transport and metabolism in rat hearts during early development. At birth, there was increased expression of fatty acid transporters and enzymes of fatty acid metabolism that allow fatty acids to become the major source of energy for cardiac muscle during the first 2 wk of life. At the same time, expression of genes that control glucose transport and oxidation was downregulated. After 2 wk, expression of genes for glucose uptake and oxidation was increased, and expression of genes for fatty acid uptake and utilization was decreased. Expression of carnitine palmitoyltransferase I (CPT I) isoforms during development was different from published data obtained from rabbit hearts. CPT I␣ and I␤ isoforms were both highly expressed in hearts before birth, and both increased further at birth. Only after the second week did CPT I␣ expression decrease appreciably below the level of CPT I␤ expression. These results represent another example of different expression patterns of CPT I isoforms among various mammalian species. In rats, changes in gene expression followed nutrient availability during development and may render cardiac fatty acid oxidation less sensitive to factors that influence malonyl-CoA content (e.g., fluctuations in glucose concentration) and thereby favor fatty acid oxidation as an energy source for cardiomyocytes in early development. carnitine palmitoyltransferase; oxidation; translocase; acetyl-CoA

Carnitine depletion in rat pups from mothers given mildronate: A model of carnitine deficiency in late fetal and neonatal life

“…Newborns must therefore develop the pathways for efficient fatty acid oxidation. In fact, at birth there was increased expression of fatty acid transporters and enzymes of fatty acid metabolism, that allow fatty acids to became the major source of energy for cardiac muscle during the first 2 weeks of life (Lavrentyev and Cook, 2004). The marked carnitine deficiency induced by mildronate in neonatal heart (70-80% reduction) observed in our experiment may have led to an impairment of lipid metabolism with a large increase of triglycerides and significant increase of CAT and CPT activities.…”

Fatty acid metabolism during maturation affects glucose uptake and is essential to oocyte competence

“…Furthermore, overexpression of glucose transporter Slc2a1 in mouse cardiac tissue increases glucose uptake and oxidation while decreasing FAO, despite a high supply of fatty acids (Yan et al 2009). A relationship between FAO and glucose consumption and oxidation has also been reported in rat hepatocytes (Berry et al 1993), rat myocytes (Abdel-aleem et al 1994), rat skeletal muscle (Kaushik et al 2001), and rat (Saddik et al 1993, Lavrentyev et al 2004) and mouse cardiac tissues (Campbell et al 2002).…”

A Case of Mistaken Identity

“…While the finding that rat FATP2 is regulated in the developing heart is still of interest, some of the key conclusions of the Lavrentyev et al study (1) regarding fatty acid transporters are clearly incorrect due to this case of mistaken identity and deserve clarification. To the Editor: Six highly homologous proteins of the fatty acid transport family (FATP) family have been identified in human and mouse genomes (FATP1-6), and their expression in human and mouse tissues have been studied to different extents (5,8,9).…”

“…To the Editor: I read the article "Expression of several genes participating in regulation of fatty acid and glucose utilization and energy metabolism in the rat heart during development" by Lavrentyev et al (1) with great interest. The authors describe the developmental regulation of several genes, including fatty acid transports, involved in cardiac lipid metabolism using cDNAs from rat hearts and real-time PCR.…”

“…It was also proposed that, in the human heart, FATP6 is colocalized with another protein involved in fatty acid transport known as fatty acid translocase (FAT/CD36) (4). FAT/CD36 is not homologous with the FATP family but seems to be important in the process of fatty acid transport into several tissues (1,4). At present, much less is known about the mechanistic and functional aspects of each of the FATPs than about their expression (9).…”