- 作者: 童吉士; 陳天華; 曾清俊; 尹在信
- 作者服務機構: 國防醫學院藥理學科; 國防醫學院生物解剖學科
- 中文摘要: 動物缺水渴飲行為發生是反應個體對於體液生理恆定的調節現象,然而,定序誘發的多飲性附屬行為,則認為非體液生理恆定需求而發生的一種個體廣泛性活動能力增強現象。由於近年發現心房利鈉因子(ANF)可能具有促進調節飲水行為之訊息液遞因子角色,本研究的目的是在比較中樞給予ANF後缺水渴飲和定序誘發多飲水兩種行為反應的異同,並且配合放射免疫定量方法,進一步觀察動物飲水前後ANF在下視丘和左右心房壁等處之含量變化。實驗結果顯示:(一)ANF中樞給藥(側腦室注射,2-8 nmol)對於缺水渴飲和定序誘發多飲行為都有抑制能力,而且都有劑量相關性作用;但是,僅有周邊大劑量注射(靜脈,8 nmol)對於缺水渴飲行為具有顯著抑制能力。(二)缺水動物心房中ANF含量比較正常動物為高,下視丘中含量則低。工具性操作行為之前,定序誘發多飲動物心房中ANF含量也較正常動物為高,但是下視丘中含量變化則不明顯。上列兩類動物令其自由飲水一小時後,心房中ANF含量均呈下降反應,但是下視丘中ANF含量則僅有定序誘發之多飲動物具有明顯的上升反應。以上結果證實缺水渴飲和定序誘發多飲動物兩者之口渴生理調節機轉相異,ANF具有負責體液恆定的控制能力。由於資料並沒有明顯的統計差異,ANF可能並不參予直接性周邊訊息液遞中樞,以達成飲水行為迴饋節制的有效生理意義。
- 英文摘要: Dehydration-induced drinking (DID) has been defined as a type of homeostatic behaviour controlledby factors related to water balance, whereas schedule-induced polydipsia (SIP) is considered to be a typeof nonhomeostatic drinking subsequent to a general increase in motor excitability. In this study, we haveattempted to assess the role of atrial natriuretic factor (ANF) in both models to elucidate the mechanismscontrolling water intake. Intracerebroventricular injection of ANF (2-8 nmol) caused a dose relatedsuppression of water intake in both DID and SIP, but intravenous injection with a higher dose of ANF (8nmol) produced a significant suppression of water intake only in DID. Before drinking started, tissueANF levels increased in atria in both models and decreased in hypothalamus in DID but not in SIP. After1 hour of drinking, ANF levels decreased in atria in both models and increased in hypothalamus in SIPbut not in DID. These results suggest that DID and SIP are different in their thirst regulation, and that thenotion that peripheral ANF serves as a humoral factor sending signals to central in the fluid homeostaticcontrol mechanism is questionable.
- 中文關鍵字: dehydration; schedule-induced polydipsia; atrial natriuretic factor
- 英文關鍵字: --