کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4325784 1614032 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The function of the adrenocortical axis in permanent middle cerebral artery occlusion: Effect of glucocorticoids on the neurological outcome
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
The function of the adrenocortical axis in permanent middle cerebral artery occlusion: Effect of glucocorticoids on the neurological outcome
چکیده انگلیسی

We characterized the effect of acute ischemic stroke on the activation of the hypothalamic–pituitary–adrenal (HPA) axis and evaluated the role of glucocorticoids (GC) in the clinical outcome following ischemic stroke. Male spontaneous hypertensive rats underwent permanent middle cerebral artery occlusion (PMCAO) and developed a cortical infarct. At 4 h post-PMCAO or sham operation, serum levels of ACTH and corticosterone (CS) were elevated 5 and 4 fold respectively as compared to controls and then returned to basal levels at 24 h post surgery. In these experimental groups we found also a significant depletion of median eminence (ME)-CRH41. In adrenalectomized (Adx) rats that underwent PMCAO the degree of motor disability and infarct volume was similar to that of intact rats. Administration of dexamethasone (Dex) to Adx-PMCAO rats significantly improved the motor disability and decreased the infarct volume. However, in sham-Adx with PMCAO, Dex had no effect on these two parameters. In rats with PMCAO or sham-PMCAO, brain production of PGE2 was significantly increased. This effect was further enhanced in Adx-PMCAO rats and significantly inhibited by Dex. In conclusion, activation of the HPA axis following PMCAO is due to stress induced by surgery. This activation is mediated by hypothalamic CRH41. Absence of endogenous GC or administration of Dex in naïve rats does not alter motor and pathological parameters in the acute stage following PMCAO. In contrast, administration of Dex significantly improved the outcome following cerebral ischemia in Adx rats which may be due to increased glucocorticoid receptors. Brain production of PGE2 does not play an important role in the pathophysiology of the acute phase of cerebral ischemia.


► Experimental cerebral ischemia activates the hypothalamic–pituitary–adrenal axis.
► The activation is due to surgical stress and not to the focal ischemia.
► Glucocorticoids do not alter motor functions and size of infarct in intact rats.
► Administration of dexamethasone to adrenalectomized rats had a beneficial effect.
► The effect of dexamethasone in adrenalectomized rats is associated with increased brain glucocorticoid receptors.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Brain Research - Volume 1407, 17 August 2011, Pages 90–96
نویسندگان
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