title: The effect of acute, chronic and chronic intermittent stress on the central noradrenergic system.
abstract: The objective of this investigation was to examine the immediate and long term effects of acute, chronic and chronic intermittent stress on the central noradrenergic system of rats. Male Sprague-Dawley rats were subjected to one hour of physical immobilization stress either as a single exposure, or as 14 exposures applied either on consecutive days, or randomly over 60 days. Animals were sacrificed immediately, 6 h and 24 h following the last stressor. Levels of norepinephrine (NE) and 3-methoxy-4-hydroxyphenylethylene-glycol sulfate (MHPG-sulfate) were measured in the hypothalamus, hippocampus, cerebral cortex and locus coeruleus region and beta-adrenergic receptor (BAR) density was determined in the cortex. Immediately after acute stress, a significant reduction in hypothalamic NE levels and marked increases in MHPG-sulfate levels in all four brain regions were observed. In contrast immediately after the last stressor of a chronic or chronic intermittent stress regimen, no change in NE concentration was observed while levels of MHPG-sulfate in the four brain regions showed a smaller increase than that observed after an acute stressor. Acute stress induced changes normalized within 6 h while chronic and chronic intermittently stressed animals had altered NE or MHPG-sulfate levels in certain brain regions for up to 6-24 h. Cortical BAR binding parameters remained unchanged after all stress paradigms.
authors.affiliation: Department of Pharmaceutics, Philadelphia College of Pharmacy and Science, PA 19104, USA.
authors.forename: E T
authors.initials: ET
authors.lastname: Hellriegel
authors.forename: A P
authors.initials: AP
authors.lastname: D'Mello
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D002908:Chronic Disease; D006624:Hippocampus / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D008125:Locus Coeruleus / Q000378:metabolism; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000378:metabolism*
chemical_list: D011943:Receptors, Adrenergic, beta; D008734:Methoxyhydroxyphenylglycol; D009638:Norepinephrine