title: Identification of an endocannabinoid system in the rat pars tuberalis-a possible interface in the hypothalamic-pituitary-adrenal system?
abstract: Endocannabinoids (ECs) are ubiquitous endogenous lipid derivatives and play an important role in intercellular communication either in an autocrine/paracrine or in an endocrine fashion. Recently, an intrinsic EC system has been discovered in the hypophysial pars tuberalis (PT) of hamsters and humans. In hamsters, this EC system is under photoperiodic control and appears to influence the secretion of hormones such as prolactin from the adenohypophysis. We investigate the EC system in the PT of the rat, a frequently used species in endocrine research. By means of immunocytochemistry, enzymes involved in EC biosynthesis, e.g., N-arachidonoyl-phosphatidylethanolamine-phospholipase D (NAPE-PLD) and diacylglycerol lipase α (DAGLα) and enzymes involved in EC degradation, e.g., fatty acid amide hydrolase (FAAH) and cyclooxygenase-2 (COX-2), were demonstrated in PT cells of the rat. Immunoreactions (IR) for FAAH and for the cannabinoid receptor CB1were observed in corticotrope cells of the rat adenohypophysis; these cells were identified by antibodies against proopiomelanocortin (POMC) or adrenocorticotrophic hormone (ACTH). In the outer zone of the median eminence, numerous nerve fibers and terminals displayed CB1IR. The majority of these were also immunolabeled by an antibody against corticotropin-releasing factor (CRF). These results suggest that the EC system at the hypothalamo-hypophysial interface affects both the CRF-containing nerve fibers and the corticotrope cells in the adenohypophysis. Our data give rise to the hypothesis that, in addition to its well-known role in the reproductive axis, the PT might influence adrenal functions and, thus, the stress response and immune system.
authors.affiliation: Dr. Senckenbergische Anatomie, Institut der Anatomie II, Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, Haus 26/EG, 60590, Frankfurt am Main, Germany.|Department für Neurologie, Klinik für Schlafmedizin und Neuromuskuläre Erkrankungen, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149, Münster, Germany.
authors.forename: Arsalan
authors.initials: A
authors.lastname: Jafarpour
authors.affiliation: Dr. Senckenbergische Anatomie, Institut der Anatomie II, Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, Haus 26/EG, 60590, Frankfurt am Main, Germany.|Institut für Anatomie und Zellbiologie, Martin-Luther-Universität Halle-Wittenberg, Große Steinstraße 52, 06097, Halle (Saale), Germany.
authors.forename: Faramarz
authors.initials: F
authors.lastname: Dehghani
authors.affiliation: Dr. Senckenbergische Anatomie, Institut der Anatomie II, Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, Haus 26/EG, 60590, Frankfurt am Main, Germany. korf@em.uni-frankfurt.de.|Dr.Senckenbergisches Chronomedizinisches Institut, Johann Wolfgang Goethe-Universität, 60590, Frankfurt Main, Germany. korf@em.uni-frankfurt.de.
authors.forename: Horst-Werner
authors.initials: HW
authors.lastname: Korf
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D063388:Endocannabinoids / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000166:cytology / Q000378:metabolism*; D008071:Lipoprotein Lipase / Q000378:metabolism; D008297:Male; D008473:Median Eminence / Q000166:cytology / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism; D010913:Pituitary-Adrenal System / Q000166:cytology / Q000378:metabolism*; D011333:Pro-Opiomelanocortin / Q000378:metabolism; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000324:Adrenocorticotropic Hormone; D000581:Amidohydrolases; D003346:Corticotropin-Releasing Hormone; D051546:Cyclooxygenase 2; D063388:Endocannabinoids; D008071:Lipoprotein Lipase; D010739:Phospholipase D; D011333:Pro-Opiomelanocortin; D043884:Receptor, Cannabinoid, CB1; D000099252:Fatty Acid Amide Hydrolases; C527163:Napepld protein, rat
keywords: Cannabinoid receptor; Corticotropin-releasing factor; Endocannabinoid system; Hypothalamic-pituitary-adrenal axis; Pars tuberalis