文蛤心肌上乙醯膽素接受器之特性

本實驗在探討文蛤（Meretrix lusoria）心肌上乙醯膽素接受器的特性。實驗時，先分離心臟，再用張力測定儀及吸引電極分別測定其收縮力及活動電位，又以乙醯膽素及其擬似劑或拮抗劑灌流離體心臟，觀察並紀錄其效應。處理30分鐘內，乙醯膽素對文蛤心肌的抑制作用具有劑量效應，有效濃度為1.0 × 10^(-11) M。若濃度為1.0 × 10^(-8) M，則在1分鐘內可達100%抑制效果。carbacol的抑制效應和乙醯膽素一樣。膽素性接受器的M型拮抗劑（atropine、scololamine），N型拮抗劑（hexamethionium bromide、curare）對乙醯膽素（10×10^(-8) M）的抑制效應有拮抗效果。本實驗證明文蛤心肌上的乙醯膽素接受器，與脊椎動物組織上的接受器不同，既不屬於M型，亦不屬於N型，可能是另一種新的類型。

關鍵字

文蛤；心臟；乙醯膽素；接受器

並列摘要

The aim of present study was to investigate the characteristics of ACh receptors on the isolated heart of a marine bivalve, Meretrix lusoria, The contractile force was measured by force transducer and the action potential recorded by suction electrode. The isolated heart activities were studied in response to the agonists and antagonists of ACh receptors. Results showed that both ACh and carbacol inhibited the heart activities with dose response. The threshold concentration is at 1.0 × 10^(-8) M. The heart activities were completely inhibited at 1.0 × 10^(-11) M after 1 minute treating. Applications of antagonists of both ACh M receptors-atropineor, scololamine and ACh N receptors-hexamethionium bromide, curare do antagonistize the inhibition of Ach onm the heart activities. This study proved that the receptor type of ACh on the marine bivalve is not similar to that of vertebrates. It is neither M type nor N type and may be a new type of ACh receptors.

並列關鍵字

Meretrix Iusoria ； heart ； Ach ； receptor

國際替代計量

文蛤心肌上乙醯膽素接受器之特性

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