AUTONOMIC MUSCARINIC RECEPTOR SIGNALING MECHANISMS

这项建议的目的是寻求药理和 回肠M2受体的神经生理功能， 气管和膀胱。已知M3毒碱能受体 引起各种平滑肌肉的收缩，这些肌肉对 M受体激动剂，但又是M受体最丰富的亚型 受体是M2，约占总密度的80% 在几块平滑的肌肉中发现了M受体。令人惊讶的是， M2受体在平滑肌中的功能本质上是未知的。它是 M2受体可能通过以下途径引起收缩的解除抑制 防止刺激其他受体引起的松弛 腺苷环化酶，就像β-肾上腺素能受体。因此， M受体亚型与其他受体的相互作用 异源受体将在信号传递方面进行研究。 机制和平滑肌的收缩能力。作为战略的一部分， 剖析M2受体在平滑肌Will中的功能作用 涉及新型失活的不可逆转拮抗剂的开发 选择性的M3受体。这些特工应该有广泛的 作为工具在多种神经药理学研究中的应用 研究M受体亚型的功能作用。 此外，这项建议中描述的研究可以提供基础 为治疗麻痹症开发更具选择性的药物 肠梗阻和青光眼，以及在精神病学中如何使用药物 干扰毒碱胆碱能机制。具体的 实验方案是：1)表征M受体 不可逆毒胆碱拮抗剂4-湿芥末的结合特性 并确定该拮抗剂阻断M3刺激的条件 不影响M2介导的磷脂酰肌醇选择性水解 抑制腺苷环化酶活性；2)开发新的、更具选择性的 4)湿芥末类似物；3)对毒鼠强的亚型进行分类 受体介导肌醇磷脂的水解和腺苷的抑制 亚型选择性毒扁豆碱测定血管内皮细胞环化酶活性 拮抗剂；4)鉴定目前存在的M受体的亚型 使用放射性配基结合技术在平滑肌组织中；5)鉴定 刺激血管内皮细胞环磷酸腺苷蓄积的受体 通过激活M2 M受体而反对的方式；6) 在Smooth中识别M受体串扰的新机制 肌肉；7)确定M2 M受体的激活是否 平滑肌阻止已识别受体介导的松弛 目的2；和8)确定精神药物是否具有药理作用 兴趣干扰Smooth M受体信号转导机制 肌肉。

The aims of this proposal are to seek out the pharmacological and neurophysiological functions of the M2 muscarinic receptor in the ileum, trachea and urinary bladder. It is known that the M3 muscarinic receptor elicits contraction in a variety of smooth muscles which respond to muscarinic agonists, yet the most abundant subtype of the muscarinic receptor is the M2, accounting for approximately 80% of the total density of muscarinic receptors in several smooth muscles. Surprisingly, the function of the M2 receptor in smooth muscle is essentially unknown. It is likely that the M2 receptor may cause a 'disinhibition of contraction' by preventing the relaxation elicited by other receptors which stimulate adenylate cyclase, like the beta-adrenergic receptor. Consequently, interactions between subtypes of the muscarinic receptor and other heterologous receptors will be investigated with respect to signaling mechanisms and contractility in smooth muscle. Part of the strategy for dissecting out the functional role of the M2 receptor in smooth muscle will involve the development of novel irreversible antagonists which inactivate M3 muscarinic receptors selectively. These agents should have widespread application as tools in a variety of neuropharmacological studies investigating the functional roles of subtypes of the muscarinic receptor. Moreover, the research described in this proposal could provide the basis for the development of more selective drugs for the treatment of paralytic ileus and glaucoma, and in determining how drugs used in psychiatry interfere with muscarinic cholinergic mechanisms. The specific experimental protocols are: 1) to characterize the muscarinic receptor binding properties of the irreversible muscarinic antagonist 4-DAMP mustard and to identify conditions where this antagonist blocks M3-stimulated phosphoinositide hydrolysis selectively without affecting M2-mediated inhibition of adenylate cyclase activity; 2) to develop new, more selective 4-DAMP mustard analogs; 3) to classify the subtypes of the muscarinic receptor mediating phosphoinositide hydrolysis and inhibition of adenylate cyclase activity in smooth muscle using subtype selective muscarinic antagonists; 4) to identify the subtypes of the muscarinic receptor present in smooth muscle using radioligand binding techniques; 5) to identify receptors which stimulate cyclic AMP accumulation in smooth muscle in a manner that is opposed by activation of the M2 muscarinic receptor; 6) to identify novel mechanisms of muscarinic receptor cross talk in smooth muscle; 7) to determine whether activation of M2 muscarinic receptors in smooth muscle prevents the relaxation mediated by the receptors identified in aim #2; and 8) to determine whether drugs of psychopharmacological interest interfere with muscarinic receptor signaling mechanisms in smooth muscle.