Schmidt Heinrich, Oettling Günter, Kaufenstein Thomas, Hartung Gisa, Drews Ulrich
Anatomisches Institut der Universität Tübingen, Osterbergstrasse 3, D-7400, Tübingen, Germany.
Wilehm Roux Arch Dev Biol. 1984 Jan;194(1):44-49. doi: 10.1007/BF00848953.
Cell suspensions of chick limb buds (stage 23/24) were loaded with the fluorescent Ca chelator chlorotetracycline. Fluorescence was monitored in a spectrofluorometer. Stimulation with acetylcholine induced a fluorescence decrease, indicating intracellular Ca mobilization. The fluorescence decrease triggered by acetylcholine was inhibited by muscarinic but not by nicotinic antagonists, indicating that a muscarinic acetylcholine receptor is involved. The muscarinic receptor in the chick limb bud has a characteristic pharmacological profile: acetylcholine, carbachol and acetyl-β-methylcholine functioned as full agonists triggering maximal fluorescence decrease. Bethanechol was less effective, producing only one-third of the maximum response. Pilocarpine and oxotremorine, two classical agonists in other systems, were ineffective and functioned as antagonists. In the chick limb bud, cholinesterase, choline acetyltransferase and the presence of a muscarinic receptor have been demonstrated in previous studies. The present experiments show that stimulation of the embryonic muscarinic receptor leads to intracellular Ca mobilization.
将鸡胚肢体芽（23/24期）的细胞悬液用荧光钙螯合剂氯四环素加载。在荧光分光光度计中监测荧光。用乙酰胆碱刺激导致荧光降低，表明细胞内钙动员。乙酰胆碱引发的荧光降低被毒蕈碱拮抗剂抑制，但不被烟碱拮抗剂抑制，表明涉及毒蕈碱型乙酰胆碱受体。鸡胚肢体芽中的毒蕈碱受体具有特征性的药理学特征：乙酰胆碱、卡巴胆碱和乙酰-β-甲基胆碱作为完全激动剂发挥作用，引发最大荧光降低。贝胆碱效果较差，仅产生最大反应的三分之一。毛果芸香碱和氧化震颤素是其他系统中的两种经典激动剂，无效且起拮抗剂作用。在先前的研究中已证明鸡胚肢体芽中存在胆碱酯酶、胆碱乙酰转移酶和毒蕈碱受体。本实验表明，刺激胚胎毒蕈碱受体可导致细胞内钙动员。
