Re: [請問]咖啡因上癮和訊息傳遞之間的關係?

看板Biology (生物學)作者vixen.時間19年前 (2006/06/06 07:01)推噓0(0推 0噓 0→)

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※ 引述《colulu ( )》之銘言： > 如題 > 咖啡因在人體的訊息傳遞pathway中是不是有明確的途徑? > 小弟上網找了很久都沒有比較完善的資料 > 但是基本的神經傳遞理論先前有建立好 > 只是不太曉得咖啡因上癮和神經、訊息傳遞上的明確關係 > 希望各位大得提供見解感恩感恩^^ 除了下面說的pathway外, 咖啡因可能也抑制mTOR pathway (in vitro), 另外印象中記得有些酵素需要咖啡因當cofactor. http://www.STKE.org Sci. STKE, Vol. 2002, Issue 146, pp. tw303, 20 August 2002. [DOI: 10.1126/stke.2002.146.tw303] NEUROBEHAVIOR: Coffee, Caffeine, and DARPP-32 Caffeine is a well-known psychostimulant that increases motor activity by inhibiting the action of the neuromodulator adenosine. By binding to adenosine receptors (A1 and A2A) present in inhibitory neurons in the brain, caffeine prevents activated A2A receptors from initiating a signaling pathway that triggers cAMP production and protein kinase A (PKA) activation. Lindskog et al. report the behavioral effects of caffeine are no longer observed in mice lacking the cytosolic protein DARPP-32. This is because caffeine increases the phosphorylation of DARPP-32 on a specific threonine residue. By blocking the cAMP-PKA pathway, caffeine decreases the action of the protein phosphatase 2A on DARPP-32. Phosphorylated DARPP-32 can then further inhibit PKA activity, amplifying the shutdown of the cAMP-PKA pathway. The effect likely includes a lower level of phosphorylated target proteins of PKA that regulate nerve activity. M. Lindskog, P. Svenningsson, L. Pozzi, Y. Kim, A. A. Fienberg, J. A. Bibb B. B. Fredholm, A. C. Nairn, P. Greengard, G. Fisone, Involvement of DARPP-32 phosphorylation in the stimulant action of caffeine. Nature 418, 774-778 (2002). -- ┌─────◆ＫＫＣＩＴＹ◆─────┐KKMAN團隊全新力作 ◎◎KKBOX◎◎ │ bbs.kkcity.com.tw │知名歌手通通都有所有新歌想聽就聽 └──《From:143.48.8.154 》──┘※※ 內容豐富多元的線上音樂台 ※※ --