Adaptation of the Adrenocortical Response during Repeated Stress in Thalamic Pigeons

Ramade, F; Baylé, J.D.

doi:10.1159/000123986

Cited by 10 publications

(2 citation statements)

References 8 publications

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“…This finding might indicate adaptations in the process regulating POMC biosynthesis. The release of corticosterone has been re ported to be reduced upon prolonged intermittent electrical foot-shock (over 4-5 weeks) in rats [17] and in pigeons [21]. In addition, Shiomi and Akil [25] found no change in the biosynthesis of POMC in anterior pituitaries obtained from rats that had been exposed to electrical foot-shock treat ment for 2 weeks.…”

Section: Discussionmentioning

confidence: 99%

Stress-Induced Alterations in the Levels of Messenger RNA Coding for Proopiomelanocortin and Prolactin in Rat Pituitary

et al. 1986

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Acute stress promotes the secretion of prolactin (PRL) and of proopiomelanocortin (POMC)-derived peptides, adrenocorticotropic hormone and β-endorphin, from the pituitary into the systemic circulation. The present study evaluates the influence of recurrent stress upon the biosynthetic activity of cells secreting these hormones in the rat. Chronic, intermittent, electrical foot-shock (3 mA 1 s duration, every 5 s for 30 min, twice daily) over a period of 1, 3 or 7 days caused an increase in messenger ribonucleic acid (mRNA) levels coding for POMC in the anterior pituitary. Maximally elevated mRNA levels were achieved after 3 days treatment (about 80% in excess of control values) which showed no further change at 7 days. These elevated levels of POMC mRNA were associated with increased levels of immunoreactive (ir)-β-endorphin in the adenohypophysis following 7 days of stress treatment. In contrast, this treatment did not significantly alter mRNA levels coding for PRL in the anterior pituitary. Similarly, POMC mRNA levels in the intermediate/posterior pituitary were also not significantly altered during exposure to repeated stress. Similar changes in the biosynthesis of the pituitary hormones were seen in rats suffering from chronic arthritic pain for 3 weeks: there was an approximately 80% increase in POMC mRNA levels in the anterior pituitary which was associated with an increase in the levels of ir-β-endorphin in this lobe and an increase in the plasma levels of ir-β-endorphin. In contrast, there were no changes in the levels of mRNA coding for PRL in the adenohypophysis. Moreover, levels of POMC mRNA and of ir-β-endorphin in the intermediate/posterior pituitary remained unchanged. It is concluded that although lactotrophic and corticotrophic cells of the adenohypophysis and corticotrophic cells in the intermediate pituitary respond similarly to acute stress stimuli with an increased secretion, the biosynthetic activity of these cells is differentially modulated under chronic stress.

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Section: Discussionmentioning

confidence: 99%

Stress-Induced Alterations in the Levels of Messenger RNA Coding for Proopiomelanocortin and Prolactin in Rat Pituitary

et al. 1986

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“…In the thalamic pigeon it was shown to depend upon photoperiodic cues [23] through retinal informations [24].…”

Section: Discussionmentioning

confidence: 99%

Effects of Chronic Intracerebroventricular GABAergic Treatment on Basal and Chronic or Acute Stress-Induced Adrenocortical Activities in the Thalamic Pigeon

Ramade¹,

Baylé²

1986

Neuroendocrinology

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Muscimol was chronically administrated to the third ventricle of thalamic pigeons by means of osmotic minipumps at the rate of 0.25 µg·h^–1 for 28 days. No abnormal behavioural sign was noted. The animals were subjected daily to chronic intermittent stress for the same 28-day period. Basal and stress-induced adrenocortical activities were evaluated by recording serial plasma corticosterone levels at the end of the experimental session. Untreated controls exhibited both components of the adaptation of the adrenocortical response to chronic stress: (1) attenuation, i.e., a decrease in magnitude and disappearance of the late rebounding phenomenon, and (2) anticipation, i.e., the occurrence of a conditioned component before stress itself. The adaptation to chronic stress was partly impaired by GABAergic treatment. The anticipatory conditioned peak subsisted but the magnitude of the post-stress peak was found not to be reduced whereas rebounding events were suppressed after chronic as well as acute stress. The basal resting levels of corticosterone were significantly lowered in muscimol-treated animals. A lesion placement in the anterior dorsomedial thalamus (ADMT) resulted in the same profile of stress-induced plasma corticosterone levels as seen after muscimol administration. Adaptation did not develop in ADMT animals and GABAergic stimulation, either acute or chronic, had no effect on their response to stress.

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Psychobiologic Mechanisms of Posttraumatic Stress Disorder

Charney¹

1993

Arch Gen Psychiatry

567

234

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Posttraumati c stress disorder (PTSD) is an illness of considerable prevalence, often characterized by high morbidity, treatment resistance, and a chronic course. The core symptoms of PTSD include persistent reexperiencing of the traumatic event, avoidance of stimuli associated with the trauma, and autonomic hyperarousal. We propose several neurobiologic mechanisms that may account for these primary symptoms of PTSD. Preclinical investi-

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Adaptation of the Adrenocortical Response during Repeated Stress in Thalamic Pigeons

Cited by 10 publications

References 8 publications

Stress-Induced Alterations in the Levels of Messenger RNA Coding for Proopiomelanocortin and Prolactin in Rat Pituitary

Stress-Induced Alterations in the Levels of Messenger RNA Coding for Proopiomelanocortin and Prolactin in Rat Pituitary

Effects of Chronic Intracerebroventricular GABAergic Treatment on Basal and Chronic or Acute Stress-Induced Adrenocortical Activities in the Thalamic Pigeon

Psychobiologic Mechanisms of Posttraumatic Stress Disorder

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