Muscarinic receptors in isolated guinea pig pancreatic ducts.
Muscarinic receptors in isolated guinea pig pancreatic ducts.
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离体豚鼠胰管中的毒蕈碱受体。
DOI：
10.1016/0006-2952(93)90417-u
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发表时间：
1993
影响因子：
5.8
通讯作者：
Kovalcik,SA
中科院分区：
文献类型：
--
作者：
Hootman,SR;Zukerman,J;Kovalcik,SA
本研究测定了豚鼠离体胰管毒蕈碱胆碱能受体的生物化学和药理学特性。导管匀浆结合6.82 ± 69 fmol [3 H] N-甲基东莨菪碱（[3 H]NMS）/μg DNA，aKd为0.73 ± 0.05 nM。同一胰腺的排泄管中[~ 3 H]NMS结合位点的密度是腺泡中的7倍。阿托品、哌仑西平、11-[[2-[（二乙基氨基）甲基]-1-哌啶基]乙酰基]-5，11-二氢-6H-吡啶并[2，3-B] [1，4]苯并二氮杂卓-6-酮（AF-DX 116）和4-二苯基乙酰氧基-N-甲基哌啶甲碘化物（4-DAMP）的竞争结合研究表明，在这些离体胰管制备物中存在M2和M3亚型的毒蕈碱受体。[3 H]丙基苄胆碱芥子标记的未还原和还原的导管毒蕈碱受体的电泳分析提供的分子量估计值分别为62.6 ± 2.5和58.0 ± 1.6 kDa。去糖基化的导管毒蕈碱受体与N-聚糖酶降低其表观分子量约4 kDa。这些结果表明，分离的胰管表达M2和M3毒蕈碱受体，前者亚型占主导地位。
Biochemical and pharmacological characteristics of muscarinic cholinergic receptors in isolated guinea pig pancreatic ducts were determined in the present study. Duct homogenates bound 6.82 ± 69 fmol of [3H]N-methylscopolamine ([3H]NMS)/μg of DNA with aKdof 0.73 ± 0.05 nM. The density of [3H]NMS binding sites in the excretory ducts was seven times greater than that in acini from the same pancreases. Competition binding studies with atropine, pirenzepine, 11-[[2-[(diethylamino)methyl]-1-piperidinyl]acetyl]-5,11-dihydro-6H-pyrido[2,3-b] [1,4]benzodiazepine-6-one (AF-DX 116), and 4-diphenylacetoxy-N-methyl piperidine methiodide (4-DAMP) indicated that both M2 and M3 subtypes of muscarinic receptors are present in these preparations of isolated pancreatic ducts. Electrophoretic analysis of [3H]propylbenzilylcholine mustard-labeled unreduced and reduced duct muscarinic receptors provided molecular mass estimates of 62.6 ± 2.5 and 58.0 ± 1.6 kDa, respectively. Deglycosylation of ductal muscarinic receptors withN-glycanase decreased their apparent molecular mass by approximately 4 kDa. These results demonstrate that isolated pancreatic ducts express both M2 and M3 muscarinic receptors, with the former subtype predominating.