کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5504165 1400217 2016 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Functional morphology of pituitary -thyroid and -adrenocortical axes in middle-aged male rats treated with Vitex agnus castus essential oil
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Functional morphology of pituitary -thyroid and -adrenocortical axes in middle-aged male rats treated with Vitex agnus castus essential oil
چکیده انگلیسی
We previously reported that Vitex agnus-castus L. essential oil (VACEO), when administered to middle-aged males, exerts a bone-protective effect, induces silencing of locomotor activities and decreases pituitary prolactin immunopositivity. To further assess the putative endocrine effects of VACEO, we examined the pituitary-thyroid and -adrenocortical axes in our model. Sixteen-month-old Wistar rats were subcutaneously administered 60 mg/kg of VACEO dissolved in sterile olive oil, while the control group received the same amount of vehicle alone for three weeks. Pituitaries, thyroids and adrenals were analyzed by qualitative and quantitative histological approaches. Concentration of thyroid stimulating hormone (TSH), total thyroxine and triiodothyronine (TH), adrenocorticotrophic hormone (ACTH), corticosterone in serum and in adrenal tissue were measured. In VACEO-treated rats, the relative volume density of pituitary thyrotrophs increased (p < 0.001), while intensity of cytoplasmic TSHβ immunostaining decreased (p < 0.001), consistent with elevated TSH in serum (p < 0.01). The thyroid tissue was characterized by a micro-follicular structure, increased relative volume of follicular epithelium (p < 0.05), decreased volume of luminal colloid (p < 0.001) and increased basolateral expression of sodium-iodide symporter-immunopositivity (p < 0.05). Serum TH also increased (p < 0.01). The relative volume density of pituitary corticotrophs decreased (p < 0.05), compatible with decline in circulating ACTH (p < 0.05). Neither tissue nor serum corticosterone levels were affected by VACEO treatment. In conclusion, the observed changes in TSH and ACTH strongly indicate central endocrine effects of prolonged VACEO treatment. In this respect, production of ACTH decreased without impact on corticosterone production. Increase in serum concentration of both TH and TSH are not compatible with a negative feedback loop and suggest a major change in set-point regulation of the hypothalamic-pituitary-thyroid axis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Histochemica - Volume 118, Issue 7, September 2016, Pages 736-745
نویسندگان
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