Effect of diet composition on coenzyme A and its thioester pools in various rat tissues Yuka Tokutake a , Wataru Iio b , Naoki Onizawa b,1 , Yuta Ogata c , Daisuke Kohari d , Atsushi Toyoda b,e , Shigeru Chohnan a,c,⇑ a Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan b Department of Biological Production Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan c Department of Bioresource Science, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan d Field Science Center, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan e Department of Biological Production Science, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan article info Article history: Received 18 May 2012 Available online 16 June 2012 Keyword: Coenzyme A Acetyl-CoA Malonyl-CoA Rats Liver CoA metabolism abstract Three coenzyme A (CoA) molecular species, i.e., acetyl-CoA, malonyl-CoA, and nonesterified CoA (CoASH), in 13 types of fasted rat tissue were analyzed. A relatively larger pool size of total CoA, consisting of acetyl-CoA, malonyl-CoA, and CoASH, was observed in the medulla oblongata, liver, heart, and brown adi- pose tissue. Focusing on changes in the CoA pool size in response to the nutrient composition of the diet given, total CoA pools in rats continuously fed a high-fat diet for 4 weeks were significantly higher in the hypothalamus, cerebellum, and kidney, and significantly lower in the liver and skeletal muscle than those of rats fed a high-carbohydrate or high-protein diet. In particular, reductions in the liver were remarkable and were caused by decreased CoASH levels. Consequently, the total CoA pool size was reduced by approximately one-fifth of the hepatic contents of rats fed the other diets. In the hypothalamus, which monitors energy balance, all three CoA molecular species measured were at higher levels when rats were fed the high-fat diet. Thus, it was of interest that feeding rats a high-fat diet affected the behaviors of CoA pools in the hypothalamus, liver, and skeletal muscle, suggesting a significant relationship between CoA pools, especially malonyl-CoA and/or CoASH pools, and lipid metabolism in vivo. Ó 2012 Elsevier Inc. All rights reserved. 1. Introduction Coenzyme A (CoA) is synthesized from a water soluble vitamin, pantothenate, through five enzymatic steps [1,2]. Since the essen- tial cofactor is utilized as a carrier of the acyl group by approxi- mately 4% of all enzymes [3], a nonesterified CoA (CoASH) or its thioesters appear in various pathways. However, the intracellular behaviors of CoASH and acyl-CoAs are not well known because the methods for determining these intracellular compounds with sufficient sensitivity have not been established. We developed an enzymatic method, the acyl-CoA cycling method [4–6]. This meth- od can detect the in vivo major CoA species of acetyl-CoA, malonyl- CoA, and CoASH to pmol levels, and it has revealed changes in the size and composition of CoASH and acyl-CoAs in bacterial cells [7–9]. Recently, analysis using the acyl-CoA cycling method was extended to mammals and the following results were obtained: (i) the role of malonyl-CoA as a regulator of food intake in hypo- thalamus [10–16], (ii) the contribution of acetyl-CoA generated from acetate to thermogenesis during fasting [16], and (iii) the enhancement of lipid degradation in cancer cachexia by decreased malonyl-CoA levels [17]. In the analysis of various tissues from rats, it has been elucidated that malonyl-CoA levels, not only in the hypothalamus but also in other brain tissues, increase in re- sponse to food intake and the liver, heart, and brown adipose tissue possess larger CoA pools than those of other tissues measured [18]. Here we describe a comprehensive analysis of CoA pools in rat tissues responding to diets with a high-carbohydrate, protein, or fat content. Intracellular CoA pools were predicted to keep a constant size, since the eukaryotic CoA biosynthetic pathway is strictly regulated by pantothenate kinases, which catalyze the committed step of the phosphorylation of pantothenate [19–21]. However, the size and composition of CoA pools consisting of acet- yl-CoA, malonyl-CoA, and CoASH were different depending on the kind of tissue, and pool sizes in the hypothalamus, cerebellum, me- dulla oblongata, liver, kidney, and skeletal muscle also changed according to differences in the nutrient composition of the fed diets. 0006-291X/$ - see front matter Ó 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.bbrc.2012.06.037 ⇑ Corresponding author at: Department of Bioresource Science, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan. Fax: +81 29 888 8672. E-mail address: chohnan@mx.ibaraki.ac.jp (S. Chohnan). 1 Present address: Ibaraki Prefectural Livestock Research Center, 1234 Negoya, Ishioka, Ibaraki 315-0132, Japan. Biochemical and Biophysical Research Communications 423 (2012) 781–784 Contents lists available at SciVerse ScienceDirect Biochemical and Biophysical Research Communications journal homepage: www.elsevier.com/locate/ybbrc