title: Improvement of obesity by activation of I1-imidazoline receptors in high fat diet-fed mice.
abstract: Imidazoline I1-receptor (I1R) is known to regulate the blood pressure, and rilmenidine, as the agonist, is used to treat hypertension in clinics. However, the role of I1R in obesity is still unclear. In the present study, we investigated the changes of obesity by activation of I1R in high fat diet (HFD)-fed mice. Chronic administration of rilmenidine into HFD-fed mice for 8 weeks significantly reduced body weight, which was reversed by efaroxan at the dose sufficient to block I1R. Also, rilmenidine significantly decreased the energy intake of HFD-fed mice. This reduction of energy intake was abolished by efaroxan at the same dosing for blockade of I1R. However, hypothalamic I1R protein expression in HFD-fed mice was markedly lower than that in normal chow-fed mice. In addition, epididymal white adipose tissue (eWAT) cell size in HFD-fed mice was decreased by rilmenidine via the activation of I1R. Moreover, effect of rilmenidine on appetite disappeared in db/db mice. Taken together, we suggest that rilmenidine can improve obesity in HFD-fed mice through an activation of I1R to ameliorate energy intake and eWAT accumulation.
authors.affiliation: Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan City, Taiwan.
authors.forename: H H
authors.initials: HH
authors.lastname: Chung
authors.forename: J- T
authors.initials: J
authors.lastname: Cheng
mesh_terms: D052436:Adipose Tissue, White / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D059305:Diet, High-Fat / Q000009:adverse effects; D002149:Energy Intake / Q000187:drug effects; D006801:Humans; D054755:Imidazoline Receptors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000188:drug therapy / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D010080:Oxazoles / Q000008:administration & dosage; D000077769:Rilmenidine
chemical_list: D054755:Imidazoline Receptors; D010080:Oxazoles; C410887:imidazoline I1 receptors; D000077769:Rilmenidine