Papers - IDA Takanori
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Identification of neuromedin S and its possible role in the mammalian circadian oscillator system Reviewed
Mori K., Miyazato M., Ida T., Murakami N., Serino R., Ueta Y., Kojima M., Kangawa K.
EMBO Journal 24 ( 2 ) 325 - 335 2005.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：EMBO Journal
The discovery of neuropeptides has resulted in an increased understanding of novel regulatory mechanisms of certain physiological phenomena. Here we identify a novel neuropeptide of 36 amino-acid residues in rat brain as an endogenous ligand for the orphan G protein-coupled receptor FM-4/TGR-1, which was identified to date as the neuromedin U (NMU) receptor, and designate this peptide 'neuromedin S (NMS)' because it is specifically expressed in the suprachiasmatic nuclei (SCN) of the hypothalamus. NMS shares a C-terminal core structure with NMU. The NMS precursor contains another novel peptide. NMS mRNA is highly expressed in the central nervous system, spleen and testis. In rat brain, NMS expression is restricted to the core of the SCN and has a diurnal peak under light/dark cycling, but remains stable under constant dar kness. Intracerebroventricular administration of NMS in rats activates SCN neurons and induces nonphotic type phase shifts in the circadian rhythm of locomotor activity. These findings suggest that NMS in the SCN is implicated in the regulation of circadian rhythms through autocrine and/or paracrine actions.
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Neuromedin U is involved in nociceptive reflexes and adaptation to environmental stimuli in mice Reviewed
Nakahara K., Kojima M., Hanada R., Egi Y., Ida T., Miyazato M., Kangawa K., Murakami N.
Biochemical and Biophysical Research Communications 323 ( 2 ) 615 - 620 2004.10
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemical and Biophysical Research Communications
Following our recent observations of inactivity and slowed movement in neuromedin U knockout (NMU KO) mice, we compared nociceptive reflexes and environmental adaptation in NMU KO and wild-type mice. Hot plate and formalin tests revealed that reflexes to heat and pain were significantly decreased in NMU KO mice. Conversely, intracerebroventricular injection of NMU into wild-type mice stimulated nociceptive reflexes in a dose-dependent manner. After NMU injection, increased c-Fos expression was observed in a wide range of locations in hypothalamus, brainstem, and spinal cord. NMU mRNA expression increased in the spinal cord, but not in the hypothalamus, 2 and 4 h after formalin injection. When their light-dark cycle was advanced or retarded by 5 h, NMU KO mice required a longer time to re-entrain into the new light-dark cycle than did wild-type mice. Wild-type mice displayed increased blood pressure after their environmental temperature was changed from 23 to 37°C, whereas no such increase was observed in NMU KO mice. Blood corticosterone levels were significantly increased after 10 min of immobilization stress in wild-type mice, but not in NMU KO mice. These results suggest that endogenous NMU may be involved in reflexes and adaptation to environmental stimuli. © 2004 Elsevier Inc. All rights reserved.
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The gut-brain peptide neuromedin U is involved in the mammalian circadian oscillator system Reviewed
Nakahara K., Hanada R., Murakami N., Teranishi H., Ohgusu H., Fukushima N., Moriyama M., Ida T., Kangawa K., Kojima M.
Biochemical and Biophysical Research Communications 318 ( 1 ) 156 - 161 2004.5
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemical and Biophysical Research Communications
Immunohistochemical analysis revealed the presence of a gut-brain peptide, neuromedin U (NMU), in the suprachiasmatic nucleus (SCN), which is the site of the master circadian oscillator. The expression of NMU mRNA exhibited a circadian rhythm, with the peak expression in the SCN occurring at CT4-8h. The two NMU-binding receptors (NMU-R1 and NMU-R2) were also expressed in the SCN, but their phase angles were different. Intracerebroventricular injection (ICV) of NMU induced the expression of Fos protein in the SCN cells and caused a phase-dependent phase shift of the circadian locomotor activity rhythm. The magnitude of th e phase shift was dose dependent. This NMU-induced phase shift was of the nonphotic type. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed increases in the expression in the SCN of immediate early genes, such as c-fos, NGFI-A, NGFI-B, and JunB. Furthermore, ICV injection of NMU increased the expression of Per1, but not Per2, in the SCN. These results indicate that NMU may play some important role in the circadian oscillator by exerting an autocrine or paracrine action in the SCN. © 2004 Elsevier Inc. All rights reserved.
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Role for central ghrelin in food intake and secretion profile of stomach ghrelin in rats Reviewed
Murakami N., Hayashida T., Kuroiwa T., Nakahara K., Ida T., Mondal M., Nakazato M., Kojima M., Kangawa K.
Journal of Endocrinology 174 ( 2 ) 283 - 288 2002.8
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Endocrinology
Ghrelin, a 28-amino-acid peptide, has recently been isolated from the rat stomach as an endogenous ligand for the GH secretagogue receptor. We have reported previously that central or peripheral administration of ghrelin stimulates food intake, and the secretion of GH and gastric acid in rats. In the present study, we investigated how much endogenous centrally released ghrelin is involved in the control of food intake and body weight gain. We also examined the profile of ghrelin secretion from the stomach by RIA using two kinds of anti-ghrelin antiserum, one raised against the N-terminal ([Cys 12 ]-ghrelin[1-11] ) region and one raised against the C-terminal ([Cys 0 ]-ghrelin [13-28] ) region of the peptide. The former antibody recognizes specifically ghrelin with n-octanoylated Ser 3 (acyl ghrelin), and does not recognize des-acyl ghrelin. The latter also recognizes des-acyl ghrelin (i.e. total ghrelin). Intracerebroventricular treatment with the anti-ghrelin antiserum against the N-terminal region twice a day for 5 days decreased significantly both daily food intake and body weight. Des-acyl ghrelin levels were significantly higher in the gastric vein than in the trunk. Either fasting for 12 h, administration of gastrin or cholecystokinin resulted in increase of both acyl and des-acyl ghrelin levels. The ghrelin levels exhibited a diurnal pattern, with the bimodal peaks occurring before dark and light periods. These two peaks were consistent with maximum and minimum volumes of gastric content respectively. These results suggest that (1) endogenous centrally released ghrelin participates in the regulation of food intake and body weight, (2) acyl ghrelin is secreted from the stomach, (3) intestinal hormones stimulate ghrelin release from the stomach, and (4) regulation of the diurnal rhythm of ghrelin is complex, since ghrelin secretion is augmented under conditions of both gastric emptying and filling.
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Ida T., Nakahara K., Kuroiwa T., Fukui K., Nakazato M., Murakami T., Murakami N.
Neuroscience Letters 293 ( 2 ) 119 - 122 2000.10
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Neuroscience Letters
Orexin (hypocretin) is a peptide that has been found to stimulate food intake in rats. However, we have recently demonstrated that orexin stimulates the release of corticotropin releasing hormone (CRF) which has been known to decrease the food intake. Therefore, we examined the mechanism of effect of orexin on food intake. Although the other appetite stimulating peptides; neuropeptide Y (NPY), agouti-related peptide (AGRP) and one of the growth hormone releasing secretagogue (GHRP-6) stimulated dose-dependently the food intake during 2 h in the early light period, orexin did not increase significantly the food intake. No significant increase was also observed during 2 h in the early dark period. However, pretreatment with α-helical CRF, an antagonist of CRF, or anti-CRF antiserum resulted in significant increase of food intake by orexin. Orexin-stimulated feeding under these conditions was blocked by NPY Y1 receptor antagonist (1229U91). In an 8 h- fasting rat, anti-orexin serum decreased slightly the food intake. These results suggest that effect of orexin on the food intake may be complex because of orexin-CRF and orexin-NPY linkage. (C) 2000 Elsevier Science Ireland Ltd.
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シマリス(T.asiaticus)における季節外冬眠誘起およびセロトニンの冬眠誘起と維持への関与(短報)
村上 昇, 幸野 亮太, 中原 桂子, 井田 隆徳, 黒田 治門
The journal of veterinary medical science 62 ( 7 ) S・viii, 763 - 766 2000.7
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：社団法人日本獣医学会
一年以上の間, 室温22度, 14時間明:10時間暗の照明条件下で飼育されたシマリスを短日照明(10時間明:14時間暗)と低温条件に暴露することにより季節外冬眠を誘起した.我々は一年のどの時期でもこの季節外冬眠を誘起できた.この季節外冬眠は季節間において, 冬眠一党醒インターバルや, それぞれの冬眠や覚醒時間には有意な差を認めなかったが, 冬眠に入るまでの期間の長さにおいて夏のみ約60日を要し, 他の季節の平均30日より長かった.さらに, 覚醒インターバルでの覚醒時刻は冬では明期に起こるのに対し, 春では明期と暗期でほぼ等しい割合で起こった.これらの結果はシマリスの冬眠がサーカディアンリズム(概日リズム)とサーカニュアルリズム(概年リズム)の両者にリンクしていることを示唆している.夏の季節外冬眠において, セロトニン枯渇剤であるパラクロロフェニルアラニン(PCPA)の冬眠中での慢性投与は冬眠を阻止し, 非冬眠動物への投与は逆に冬眠を誘発した.一方, オピオイドのアンタゴニストであるナロキソンの投与は覚醒時間の延長を起こした.これらの結果は, セロトニンによる冬眠誘超や維持機構がサーカニュアル(概年リズム)システムと独立したものであることを示唆している.
DOI： 10.1292/jvms.62.763
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Induction of unseasonable hibernation and involvement of serotonin in entrance into and maintenance of its hibernation of chipmunks T. asiaticus Reviewed
Murakami N, et al.
J Vet Med Sci 62 ( 7 ) 763 - 766 2000.7
Language：English Publishing type：Research paper (scientific journal)
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Murakami N., Kono R., Nakahara K., Ida T., Kuroda H.
Journal of Veterinary Medical Science 62 ( 7 ) 763 - 766 2000.7
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Veterinary Medical Science
Chipmunks that had been housed at 22°C under a light-dark cycle of 14L:10D for at least one year were exposed to a short photoperiod (10L:14D) and low temperature to induce unseasonable hibernation. We were able to induce hibernation at any time of year and there was no significant difference in the duration of the hibernation bout, the duration of interbout euthermia and duration of bouts of torpor throughout the year; however entrance into hibernation took about 60 days in summer but only about 30 days in any other seasons. In addition, interbout euthermia predominantly occurred during the light phase in winter, whereas in spring interbout euthermia occurred equally in the light and dark phases. These results suggest that both the circadian and circannual systems are linked to hibernation in chipmunks. Subcutaneous infusion of a serotonin antagonist, para-chlorophenylalanine (PCPA), facilitated entrance into and interrupted hibernation in aroused and hibernating chipmunks in summer, respectively. On the other hand, opioid antagonist, naloxone, did not affect hibernation, but extended the period of interbout euthermia. These results suggest that the role of serotonin in entrance into and maintenance of hibernation in chipmunks is independent of the circannual system, and that opioid system may not be involved in hibernation in chipmunks.
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Possible involvement of orexin in the stress reaction in rats Reviewed
Ida T., Nakahara K., Murakami T., Hanada R., Nakazato M., Murakami N.
Biochemical and Biophysical Research Communications 270 ( 1 ) 318 - 323 2000.4
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Biochemical and Biophysical Research Communications
We examined whether corticotropin-releasing factor (CRF) was involved in orexin-induced grooming and face-washing behaviors, and whether orexin was involved in the stress reaction. Administration of α-helical CRF, CRF antagonist, alone had no behavioral effect, but it blocked the orexin-induced grooming and face-washing behaviors in rats. The level of corticosterone increased in a dose-dependent manner 15 min after icy injection of orexin, and it remained high for at least 60 min. In 2-month-old rats, 1 h of immobilization stress increased orexin mRNA levels, but not the melanin-concentrating hormone (MCH) mRNA, in the lateral hypothalamic area (LHA). In 6-month-old rats, 30 min of cold stress increased the expression of orexin mRNA in the LHA. Unlike in the 2-month-old rats, immobilization stress did not change orexin mRNA expression in 6-month-old rats. These results suggest that CRF is involved in orexin-induced behaviors, and that orexin may play an important role in some stress reactions. (C) 2000 Academic Press.
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Ida T., Nakahara K., Katayama T., Murakami N., Nakazato M.
Brain Research 821 ( 2 ) 526 - 529 1999.3
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Brain Research
The effect of lateral cerebroventricular injection of the appetite- stimulating neuropeptide, orexin and neuropeptide Y (NPY), on the behavior of rats was investigated. An immediate increase in face washing activity was observed after injection of orexin A or orexin B, but not NPY. Orexin A had a more potent effect on face washing behavior than orexin B. Grooming and burrowing activities also increased significantly after injection of orexin A, whereas, orexin B significantly increased burrowing and searching behavior. Feeding behavior and food consumption increased dramatically within 10 min of injection of NPY. Although the significant increase in feeding behavior was also observed after injection of orexin A, total food intake did not change significantly. These results suggest that orexin may be involved in the regulation of several other behavioral activities in rats, besides feeding.