title: Inhibition of nitric oxide synthase induces ultrastructural changes in the neurohypophysis of dehydrated rats.
abstract: Neuroglial relation in the rat neurohypophysis have been shown previously to change significantly after an acute dehydration stimulus. Here, we demonstrate a significant role for nitric oxide as a mediator of this response. Adult male rats were injected (i.p.) with 1.5 M NaCl or with 1.5 M NaCl and N omega-nitro-L-arginine methyl ester (L-NAME) an inhibitor of nitric oxide synthase. Five hours after the dehydration stimulus, animals were perfusion fixed and the ultrastructure of their neurohypophyses examined. Neurohypophyses of animals injected with L-NAME and NaCl had significantly less contact between the basal lamina and the membrane of axon terminals than those of animals injected only with NaCl. There was also a significantly larger number of axonal profiles enclosed within neurohypophysial astrocytes in L-NAME and NaCl injected animals than in animals injected only with NaCl.
authors.affiliation: Department of Psychology, Alma College, MI 48801, USA. beagleyg@alma.edu
authors.forename: G H
authors.initials: GH
authors.lastname: Beagley
authors.forename: P
authors.initials: P
authors.lastname: Cobbett
mesh_terms: D000818:Animals; D003681:Dehydration / Q000473:pathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D010904:Pituitary Gland, Posterior / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D012965:Sodium Chloride; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester