TY - JOUR
T1 - Involvement of the orexin system in sympathetic nerve regulation
AU - Murakami, Manabu
AU - Ohba, Takayoshi
AU - Kushikata, Testuya
AU - Niwa, Hidetoshi
AU - Kurose, Akira
AU - Imaizumi, Tadaatsu
AU - Watanabe, Hiroyuki
AU - Yanagisawa, Teruyuki
AU - Nakaji, Shigeyuki
AU - Ono, Kyoichi
AU - Hirota, Kazuyoshi
N1 - Funding Information:
This research was sponsored in part by Grants-in-Aid for Scientific Research from JSPS, KAKENHI ( 25460293 ), The Center of Healthy Aging Innovation (COI), the Special Project of Three Northern Tohoku Universities, and a program titled “Influence of socio-environmental factors on the progression of atherosclerosis among the general population.”
Publisher Copyright:
© 2015 Elsevier Inc. All rights reserved.
PY - 2015/5/12
Y1 - 2015/5/12
N2 - Orexin, also known as hypocretin, is a secreted neuropeptide implicated in the regulation of sleep and food intake. In the present study, we examined the importance of orexin in regulation of the sympathetic nervous system using an orexin/ataxin-3 transgenic (OXTg) rat, which has a minimal number of orexin neurons. RT-PCR analysis identified expression of prepro-orexin and orexin receptor-1 (OX1R) in the superior cervical ganglion (SCG), and expression of another receptor (OX2R) was marginal in the wild-type rat. The orexin/ataxin-3 transgenic rat showed increased expression of OX1R and OX2R, whereas expression of prepro-orexin was undetectable, suggesting a compensatory increase in both receptors. In the ECG recording (R-R interval), orexin/ataxin-3 transgenic rats showed decreased responsiveness to the β-adrenergic blocker propranolol. Furthermore, OXTg rats had deteriorated R-R interval regulation, indicating involvement of the orexin system in sympathetic nerve regulation. This was accompanied by decreased baroreflex and responsiveness to β-adrenergic blocker in blood pressure recording, also suggesting involvement of the orexin system in sympathetic nerve regulation. Histological examination revealed hypotrophic changes in the transgenic heart, suggesting involvement of the orexin system in cardiac development. Taken together, our present results indicate involvement of the orexin system in sympathetic nerve control.
AB - Orexin, also known as hypocretin, is a secreted neuropeptide implicated in the regulation of sleep and food intake. In the present study, we examined the importance of orexin in regulation of the sympathetic nervous system using an orexin/ataxin-3 transgenic (OXTg) rat, which has a minimal number of orexin neurons. RT-PCR analysis identified expression of prepro-orexin and orexin receptor-1 (OX1R) in the superior cervical ganglion (SCG), and expression of another receptor (OX2R) was marginal in the wild-type rat. The orexin/ataxin-3 transgenic rat showed increased expression of OX1R and OX2R, whereas expression of prepro-orexin was undetectable, suggesting a compensatory increase in both receptors. In the ECG recording (R-R interval), orexin/ataxin-3 transgenic rats showed decreased responsiveness to the β-adrenergic blocker propranolol. Furthermore, OXTg rats had deteriorated R-R interval regulation, indicating involvement of the orexin system in sympathetic nerve regulation. This was accompanied by decreased baroreflex and responsiveness to β-adrenergic blocker in blood pressure recording, also suggesting involvement of the orexin system in sympathetic nerve regulation. Histological examination revealed hypotrophic changes in the transgenic heart, suggesting involvement of the orexin system in cardiac development. Taken together, our present results indicate involvement of the orexin system in sympathetic nerve control.
KW - ECG
KW - Orexin
KW - Rat
KW - Sympathetic nerve
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U2 - 10.1016/j.bbrc.2015.03.157
DO - 10.1016/j.bbrc.2015.03.157
M3 - Article
C2 - 25849891
AN - SCOPUS:84937762538
SN - 0006-291X
VL - 460
SP - 1076
EP - 1081
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 4
ER -