NEUROENDOCRINOLOGYProgesterone receptor immunoreactivity in the brains of ovariectomized aged ratsFuruta, Miyakoa; Fukushima, Atsushib c; Chiba, Shuichie; Sano, Akaneb; Akema, Tatsuoa; Kimura, Fukukob d; Funabashi, Toshiyaa b Author Information aDepartment of Physiology, St Marianna University School of Medicine, Miyamae-ku, Kawasaki bDepartment of Physiology, Yokohama City University School of Medicine, Kanazawa-ku, Yokohama cDepartment of Neurobiology and Anatomy, Kochi Medical School, Nankoku dInternational University of Health and Welfare, Minamiaoyama, Minato-ku eDepartment of Mental Disorder Research, National Center of Neurology and Psychiatry, Tokyo, Japan Correspondence to Professor Toshiya Funabashi, MD, PhD, Department of Physiology, St Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki 216-8511, Japan Tel: +81 44 977 8111; fax: +81 44 977 0172; e-mail: [email protected] Received 19 May 2010 accepted 20 May 2010 NeuroReport: August 4, 2010 - Volume 21 - Issue 11 - p 777-781 doi: 10.1097/WNR.0b013e32833c5b6f Buy Metrics Abstract We examined the induction of progesterone receptor-immunoreactive (PR-ir) cells by estrogen in the rat preoptic area and ventromedial hypothalamic nucleus. Ovariectomized young (3-month-old) and old (24-month-old) female rats were treated with estrogen or cholesterol for 4 days. Estrogen significantly increased PR-ir cells in the preoptic area and ventromedial hypothalamic nucleus in young rats. Cholesterol-treated old rats had very few PR-ir cells; estrogen treatment significantly increased the number of PR-ir cells in both the preoptic area and the ventromedial hypothalamic nucleus in old rats, although less than in young rats. Therefore, the ability of estrogen to induce PR immunoreactivity in the hypothalamus in ovariectomized rats is attenuated in old rats compared with young rats. © 2010 Lippincott Williams & Wilkins, Inc.