کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1907523 | 1046369 | 2006 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Age-related changes in circadian rhythm of serotonin synthesis in ring doves: Effects of increased tryptophan ingestion
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موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
سالمندی
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چکیده انگلیسی
Alterations in the function of the hypothalamic suprachiasmatic nucleus (SCN) with age have been reported. As serotonin is an important regulator of the circadian clock located in SCN, this work studied the changes produced in the synthesis of serotonin with age using the accumulation of 5-HTP after decarboxylase inhibition as a measure of serotonin synthesis in the brain in vivo, in young and old ring doves at the onset of lights-on and lights-off. A diurnal cycle in tryptophan hydroxylation was observed in young animals, with an increased daylight synthesis and metabolism of 5-HT in hippocampus, neostriatum and hypothalamus. A single dose of melatonin (1Â mg/kg, i.p., 1Â h) at lighttime produced an inhibitory effect on the synthesis of 5-HT. In contrast, differences in 5-HT synthesis and metabolism between day and night dissappeared in old animals indicating an absence of a circadian rhythm in 5-HT synthesis and metabolism. The administration of l-tryptophan (240Â mg/kg, i.p.) strongly increased the 5-HT synthesis in young animals only during lights-off time while it increased in old ones irrespective of the administration time. These results suggest that the supplemental administration of tryptophan might aid to improve the descent in 5-HT that normally occurs, as animals get old.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Gerontology - Volume 41, Issue 1, January 2006, Pages 40-48
Journal: Experimental Gerontology - Volume 41, Issue 1, January 2006, Pages 40-48
نویسندگان
Celia Garau, Sara Aparicio, Rubén V. Rial, MarÃa C. Nicolau, Susana Esteban,