کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10958473 1100072 2005 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Acute administration of alcohol modulates pyroglutamyl amino peptidase II activity and mRNA levels in rat limbic regions
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Acute administration of alcohol modulates pyroglutamyl amino peptidase II activity and mRNA levels in rat limbic regions
چکیده انگلیسی
Released TRH is inactivated by an ectopeptidase, pyroglutamyl aminopeptidase II (PPII). PPII expression and activity are stringently regulated in adenohypophysis, and in rat brain, during kindling stimulation that activates TRHergic neurons. To gain further insight into the possible regulation of PPII, we studied the effect of an acute intraperitoneal ethanol administration that affects TRH content and expression. PPII activity was determined by a fluorometric assay and PPII mRNA levels by semi-quantitative RT-PCR. Activity decreased in frontal cortex 1 h after ethanol injection and, after 6 h, in hippocampus, amygdala and n. accumbens. PPII mRNA levels decreased at 30 and 60 min in frontal cortex and n. accumbens while increased at longer times in these regions and, in hippocampus and hypothalamus. NMDA and GABAA receptors' agonists and antagonists were tested at 1 h (±ethanol) on PPII activity and mRNA levels, as well as on TRH content and its mRNA. In n. accumbens, PPII mRNA levels decreased by ethanol, MK-801, and muscimol while picrotoxin or NMDA reversed ethanol's inhibition. Ethanol decreased TRH content and increased TRH mRNA levels as MK-801 or muscimol did (NMDA or picrotoxin reverted the effect of ethanol). In frontal cortex, PPII activity was inhibited by ethanol, NMDA and MK-801 with ethanol; its mRNA levels were reduced by ethanol, MK-801 and muscimol (NMDA and picrotoxin reverted ethanol's inhibition). These results show that PPII expression and activity can be regulated in conditions where TRHergic neurons are modulated. Effects of ethanol on PPII mRNA levels as well as those of TRH and its mRNA may involve GABA or NMDA receptors in n. accumbens. Changes observed in frontal cortex suggest combined effects with stress. The response was region-specific in magnitude, tendency and kinetics. These results give further support for brain PPII regulation in conditions that modulate the activity of TRHergic neurons.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neurochemistry International - Volume 46, Issue 4, March 2005, Pages 347-356
نویسندگان
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