title: Participation of the intermediate lobe of the pituitary gland after prolonged exposure to unpredictable stress in the rat.
abstract: An ultrastructural study is described which related cellular activity in the intermediate lobe of the pituitary gland with circulating levels of corticosterone. Exposure of male CSF rats to a signalled, unpredictable 60-day stress regimen induced intense secretory activity in all cells of the pars intermedia for the first 5 days of stressing, and thereafter secretory activity reverted back to the control condition. Blood corticosterone levels showed an initial extreme increase lasting for the first 5 days of exposure to the stress before gradually falling to re-establish a new stable level of secretion by 40 days. The possible involvement of the intermediate lobe in emotional or psychological stress when corticosterone levels are high is discussed.
mesh_terms: D000311:Adrenal Glands / Q000502:physiology*; D000818:Animals; D003345:Corticosterone / Q000097:blood* / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D010902:Pituitary Gland / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D013312:Stress, Physiological; D013997:Time Factors
chemical_list: D003345:Corticosterone