Effects of Fasting on Circadian-Clock Gene Expressions in Rat Colons

大鼠結腸生物時鐘基因在禁食狀態的表現

楊淑娟(Shu-Chuan Yang)

《慈濟技術學院學報》 19期 (2012/07) Pp. 1-16-1

https://doi.org/10.6975/JTCCT.201207.016a

摘要

地球上的生物體常見的節律稱之為日變節律。以哺乳類而言，主要的分子生物時鐘系統在調節日變節律活動方面扮演了一個重要的角色。近年來的研究顯示生物時鐘基因在胃腸道有日變節律的表現，進而認為這些生物時鐘基因可能扮演著維持胃腸道功能恆定的角色。本研究的主要目的在確立大鼠結腸生物時鐘基因的表現變化，及禁食是否會對生物時鐘基因的表現造成影響。利用即時定量聚合脢連鎖反應法來偵測基因的表現，發現雄性大鼠結腸的生物時鐘基因，如期間基因1、2、3，腦與肌肉ARNT 相似基因1，感光色素基因1、2 具有日變節律表現，但時鐘基因則沒有表現節律現象。禁食會使期間基因1、2、3，腦與肌肉ARNT相似基因1，感光色素基因1、2 等生物時鐘基因的表現量提升，但並不干擾其原有的節律形式。雖然時鐘基因的表現並無節律性，但禁食仍會使該基因表現量提升。這些結果顯示，生物時鐘基因在胃腸道可能扮演著恆定功能的角色。

關鍵字

日變節律 ； 時鐘基因 ； 結腸 ； 禁食 ； 限制飲食 ； 體重

並列摘要

The most common rhythm of organisms on earth is the circadian rhythm. In mammals, the main molecular circadian-clock systems are originally found to play important roles in regulating circadian rhythms. Recent studies showed that circadian patterns of circadian-clock genes exist in the gastrointestinal tract and implied that these genes might play an important role in the homeostasis of gastrointestinal functions. The main objective in this study is to build up the patterns of circadian-clock gene expressions in the colons of rats and to study whether fasting affect these circadian-clock gene expressions. Using the real-time quantitative PCR as the tool to detect gene expressions, we found that the circadian-clock genes, Period1 (Per1), Per2, Per3, brain and muscle Arnt like protein 1 (Bmal1), Crytochrome1 (Cry1) and Cry2 showed the diurnal patterns in male rat colons, but the circadian locomotor output cycle kaput (Clock) had no rhythmicity. Fasting elevated the levels of Per1, Per2, Per3, Bmal1, Cry1 and Cry2 mRNA expressions at all time points, but did not interrupt the rhythmic patterns. Although the Clock mRNA expression did not show the rhythmic pattern, fasting still elevated its expression levels. These data implied that the circadian-clock genes in the gastrointestinal tract might play a homeostasis role.

並列關鍵字

diurnal rhythm ； Clock ； colon ； fasting ； food deprivation ； body weight