title: Immobilization stress affects oxytocin and vasopressin levels in hypothalamic and extrahypothalamic sites.
abstract: Oxytocin (OT) and vasopressin (VP) have been localized in various sites within the central nervous system outside the classic hypothalamo-neurohypophyseal axis. This study investigated the effect of immobilization stress on the levels of OT and VP in the hypothalamus, pons-medulla, and the cervical, thoracic, and lumbosacral segments of the spinal cord. Male Long Evans rats were immobilized for 1 min and sacrificed by guillotine. The tissues were dissected out and homogenized in 0.1 N HCl. The hormone content was determined by radioimmunoassay (RIA) in Sep-pak extracted samples. The data show a decrease in OT content of 33.6% (P less than 0.02) and 42.4% (P less than 0.01) in the hypothalamus and pons-medulla, respectively. In the spinal cord, however, OT levels were increased by 39.1% (not significant), 51.1% (P less than 0.05), and 87.6% (P less than 0.001) in the cervical, thoracic, and lumbosacral segments respectively. The VP content of the hypothalamus and pons-medulla did not change. However, in the spinal cord, the VP content was also increased by 101.4% (P less than 0.01) and by 143.7% (P less than 0.01) in the cervical and lumbosacral segments. The levels of VP in the thoracic segment did not change. The data demonstrate that stress can alter hypothalamic and extra-hypothalamic levels of OT as well as spinal cord levels of VP. The exact physiological effects of these changes, particularly within the spinal cord, remain to be elucidated.
authors.affiliation: Department of Biological Sciences, St. John's University, Jamaica, NY 11439.
authors.forename: C
authors.initials: C
authors.lastname: Miaskowski
authors.forename: G L
authors.initials: GL
authors.lastname: Ong
authors.forename: D
authors.initials: D
authors.lastname: Lukic
authors.forename: J
authors.initials: J
authors.lastname: Haldar
mesh_terms: D000818:Animals; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism; D009928:Organ Specificity; D010121:Oxytocin / Q000378:metabolism*; D011149:Pons / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D012016:Reference Values; D012149:Restraint, Physical; D013116:Spinal Cord / Q000378:metabolism*; D013315:Stress, Psychological / Q000503:physiopathology*; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D014667:Vasopressins; D010121:Oxytocin