Liver metabolomic analysis in broiler chicks: Profiling the metabolites after oral administration of l‐citrulline

Abstract

Hypothermia is directly linked to metabolism; however, it is still unknown how the overall metabolism is altered by oral administration of hypothermic agent, L-citrulline (L-Cit). The present study aimed to determine the characteristics of liver metabolites of chicks orally administered L-Cit to provide a greater understanding of its metabolism. Capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS) and liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS) were conducted on liver samples after oral administration of L-Cit. A total of 361 liver metabolites were identified. Although a small number of samples were used for each group, a principal component analysis and heatmap patterns confirmed that the composition of metabolites could be segregated from each other. Of the 361 compounds detected in the liver, 41 compounds, including amino acids related to the Cit-arginine (Arg) cycle, argininosuccinic acid, Arg, ornithine, and Cit, as well as gamma aminobutyric acid, glycine, histidine, and nicotinamide adenine dinucleotide were abundant in L-Cit-treated livers. In contrast, 24 compounds containing fatty acids, amino acids, and cyclic adenosine monophosphate were lower in the L-Cit group. These data imply that the active Cit-Arg cycle, TCA cycle metabolism, and a low activity in fatty acid metabolism occur in L-Cit-treated broiler chicks.

Efficacy of hepatoprotectors in prophylaxis of hepatosis of laying hens

“…In the analysis of protein metabolism, an important role belongs to the identification of concentrations of total protein and its fraction in the blood (Chowdhury et al, 2021). According to the data (Bashchenko et al, 2021;Brezvyn et al, 2021;, the concentrations of the overall protein during various pathological conditions of the liver may increase, decrease or remain in the norm.…”

L‐Citrulline: A novel hypothermic amino acid promoting thermotolerance in heat‐exposed chickens

“…It has also been found that orally administered L‐Cit results in increased liver Cit, argininosuccinate, NAD + , and NAD + hydrogen (H) (NADH), which indicates the activation of the Krebs cycle. Furthermore, ATP concentration was found to have increased in one of three liver samples, which suggests that anabolic metabolism might have been stimulated by the oral administration of L‐Cit (Figure 2; Chowdhury, Ouchi, Haraguchi, & Bungo, 2021).…”

“…A metabolomic study aimed at revealing the characteristics of liver metabolites of chicks that had been orally administered L‐Cit was recently carried out to shed more light on the metabolism of L‐Cit (Chowdhury, Ouchi, Haraguchi, & Bungo, 2021). In this study, capillary electrophoresis–time‐of‐flight mass spectrometry (CE‐TOFMS) and liquid chromatography–time‐of‐flight mass spectrometry (LC‐TOFMS) were carried out on liver samples following the oral administration of L‐Cit.…”

“…It has thus been demonstrated that dietary L‐Cit can promote muscle ATP generation during heat stress in broilers (Uyanga, Zhao, et al, 2022). It has also been reported that oral administration of L‐Cit caused an increase in the liver of both NADH and NAD + , which are electron carriers and may increase oxidative phosphorylation activity in the mitochondria (Chowdhury, Ouchi, Haraguchi, & Bungo, 2021). Although ATP was not detected in all the groups, it did increase in one sample in the L‐Cit group (Chowdhury, Ouchi, Haraguchi, & Bungo, 2021).…”

“…It has also been reported that oral administration of L‐Cit caused an increase in the liver of both NADH and NAD + , which are electron carriers and may increase oxidative phosphorylation activity in the mitochondria (Chowdhury, Ouchi, Haraguchi, & Bungo, 2021). Although ATP was not detected in all the groups, it did increase in one sample in the L‐Cit group (Chowdhury, Ouchi, Haraguchi, & Bungo, 2021). These results indicate that ATP production may be enhanced by orally administered L‐Cit, and thus, an anabolic activity could be promoted, which might help in lowering the body temperature, because catabolic metabolism under HT increases body temperature (Chowdhury et al, 2012; Maeda et al, 2017; Shim et al, 2006).…”