Poster Presentation The International Congress of Neuroendocrinology 2014

A role of nesfatin-1/NucB2 in dehydration-induced anorexia (#396)

Mitsuhiro Yoshimura 1 , Takanori Matsuura 1 , Junichi Ohkubo 1 , Takashi Maruyama 1 , Toru Ishikura 1 , Hirofumi Hashimoto 1 , Tetsuya Kakuma 2 , Masatomo Mori 3 , Yoichi Ueta 1
  1. Department of Physiology, University of Occupational and Environmental Health, Japan, Kitakyushu
  2. Department of Endocrine, Metabolism, Kidney, and Collagen disease, Oita University, Oita
  3. Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi

Nesfatin-1/NucB2, an anorexigenic molecule, is expressed mainly in the hypothalamus, particularly in the supraoptic nucleus (SON) and the paraventricular nucleus (PVN). Nesfatin-1/NucB2 is also expressed in the subfornical organ (SFO). Because the SON and PVN are involved in body fluid regulation, nesfatin-1/NucB2 may be involved in dehydration-induced anorexia. To clarify the effects of endogenous nesfatin-1/NucB2, we studied changes in nesfatin-1/NucB2 mRNA levels in the SFO, SON, and PVN in adult male Wistar rats after exposure to osmotic stimuli by using in situ hybridization histochemistry. Considerable increases in nesfatin-1/NucB2 mRNA levels were observed in the SFO, SON, and PVN following water deprivation for 48 h, consumption of 2% NaCl hypertonic saline in drinking water for 5 days, and polyethylene glycole-induced hypovolemia. In addition, nesfatin-1/NucB2 expression was increased in response to water deprivation in a time-dependent manner. These changes in nesfatin-1/NucB2 mRNAexpression were positively correlated with plasma sodium concentration, plasma osmolality, and total protein levels in all the examined nuclei. Immunohistochemistry for nesfatin-1/NucB2 revealed that nesfatin-1/NucB2 protein levels were also increased after 48 h of dehydration and attenuated by 24 h of rehydration. Moreover, intracerebroventricular administration of nesfatin-1/NucB2 neutralizing antibody after 48 h of water deprivation resulted in a significant increase in food intake compared to administration of vehicle alone. These results suggested that nesfatin-1/NucB2 is a crucial peptide in dehydration-induced anorexia.