TY - JOUR
T1 - L-Citrulline acts as potential hypothermic agent to afford thermotolerance in chicks
AU - Chowdhury, Vishwajit S.
AU - Han, Guofeng
AU - Bahry, Mohammad A.
AU - Tran, Phuong V.
AU - Do, Phong H.
AU - Yang, Hui
AU - Furuse, Mitsuhiro
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science [grant number 15K07694] and by a grant from the Kieikai 2015 Research Foundation, Japan to VSC.
Publisher Copyright:
© 2017 Elsevier Ltd
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2017/10
Y1 - 2017/10
N2 - Recently we demonstrated that L-citrulline (L-Cit) causes hypothermia in chicks. However, the question of how L-Cit mediates hypothermia remained elusive. Thus, the objective of this study was to examine some possible factors in the process of L-Cit-mediated hypothermia and to confirm whether L-Cit can also afford thermotolerance in young chicks. Chicks were subjected to oral administration of L-Cit along with intraperitoneal injection of a nitric oxide synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester HCl (L-NAME), to examine the involvement of NO in the process of hypothermia. Food intake and plasma metabolites were also analyzed after oral administration of L-Cit in chicks. To examine thermotolerance, chicks were orally administered with a single dose of L-Cit (15 mmol/10 ml/kg body weight) or the same dose twice within a short interval of 1 h (dual oral administration) before the exposure to high ambient temperature (35 ± 1 °C) for 180 min. Although the rectal temperature was reduced following administration of L-Cit, L-NAME caused a greater reduction. L-NAME reduced total NO2 and NO3 (NOx) in plasma, which confirmed its inhibitory effect on NO. A single oral administration of L-Cit mediated a persistent state of hypothermia for the 300 min of the study without affecting food intake. It was further found that plasma glucose was significantly lower in L-Cit-treated chicks. Dual oral administration of L-Cit, but not a single oral administration, afforded thermotolerance without a significant change in plasma NOx in chicks. In conclusion, our results suggest that L-Cit-mediated hypothermia and thermotolerance may not be involved in NO production. L-Cit-mediated thermotolerance further suggests that L-Cit may serve as an important nutritional supplement that could help in coping with summer heat.
AB - Recently we demonstrated that L-citrulline (L-Cit) causes hypothermia in chicks. However, the question of how L-Cit mediates hypothermia remained elusive. Thus, the objective of this study was to examine some possible factors in the process of L-Cit-mediated hypothermia and to confirm whether L-Cit can also afford thermotolerance in young chicks. Chicks were subjected to oral administration of L-Cit along with intraperitoneal injection of a nitric oxide synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester HCl (L-NAME), to examine the involvement of NO in the process of hypothermia. Food intake and plasma metabolites were also analyzed after oral administration of L-Cit in chicks. To examine thermotolerance, chicks were orally administered with a single dose of L-Cit (15 mmol/10 ml/kg body weight) or the same dose twice within a short interval of 1 h (dual oral administration) before the exposure to high ambient temperature (35 ± 1 °C) for 180 min. Although the rectal temperature was reduced following administration of L-Cit, L-NAME caused a greater reduction. L-NAME reduced total NO2 and NO3 (NOx) in plasma, which confirmed its inhibitory effect on NO. A single oral administration of L-Cit mediated a persistent state of hypothermia for the 300 min of the study without affecting food intake. It was further found that plasma glucose was significantly lower in L-Cit-treated chicks. Dual oral administration of L-Cit, but not a single oral administration, afforded thermotolerance without a significant change in plasma NOx in chicks. In conclusion, our results suggest that L-Cit-mediated hypothermia and thermotolerance may not be involved in NO production. L-Cit-mediated thermotolerance further suggests that L-Cit may serve as an important nutritional supplement that could help in coping with summer heat.
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U2 - 10.1016/j.jtherbio.2017.07.007
DO - 10.1016/j.jtherbio.2017.07.007
M3 - Article
C2 - 29037378
AN - SCOPUS:85025615309
VL - 69
SP - 163
EP - 170
JO - Journal of Thermal Biology
JF - Journal of Thermal Biology
SN - 0306-4565
ER -