PHARMACOLOGY OF RYANODINE AND THE SR CA CHANNEL

实验的目的首先是要确定阿司匹林的体外效应。 兰诺定及其一系列结构类似物对钙离子的影响 大豆分离的SR膜的通透性和钙结合特性 骨骼、心脏和血管的平滑肌肉。第二，我们将确定 这些化合物的作用的生理后果通过 表征它们在完整肌肉功能上所产生的变化 准备工作。在初步研究中，我们发现两种地特平 Ryanodine的酯类类似物，命名为A和B，每种只引起一种 兰诺定的作用。因此，这些化合物可能会选择性地增加 并降低SR膜的钙通透性，并可能激活和 抑制钙释放通道。 1.我们将从Ryania木材中提取和纯化以下化合物： 兰尼定、脱氢氰诺定和标示为A、B、C1的地特平酯， C2和D。此外，兰诺定将被化学修饰以形成 9-表氧核苷、异脱氢核苷、脱水核苷、氧核苷、 兰诺醇和吡咯-2-羧酸。 2.在一系列体外研究中，我们将建立和比较 兰尼定及其类似物对被动和主动钙离子通量的影响 从骨骼分离的SR膜的跨膜和钙结合， 心脏和光滑的肌肉。我们还将确定这些措施的影响 化合物对钙离子电导和活化特性的影响 从膜组分发现的掺入脂质双层的通道 受到生物碱的影响。将对无效化合物进行测试 它们有能力对抗那些被发现作用于 受兰诺定影响的部位之一。结构-活性信息 从这些研究中获得的信息将被用来识别结构 兰尼定分子的特征对每一种活性都很重要。 3.我们将确定每种化合物改变 氧耗量、胞浆钙活性和机械和 完整的骨骼、心脏和平滑肌肉的电功能。我们 将关联在这些研究中获得的结构-活性关系 与前一步骤中确定的那些进行现场研究，以便 建立体外培养细胞之间存在的因果关系 肌质网钙运动的变化及完整肌肉的变化 由这些化合物产生的功能。

The goals of the experiments first, to establish the in vitro effects of ryanodine and a series of structural analogs of ryanodine on the calcium permeability and calcium binding properties of SR membranes isolated from skeletal, cardiac and vascular smooth muscles. Second, we will determine the physiological consequences of the actions of these compounds by characterizing the changes they produce in the function of intact muscle preparations. In preliminary studies we have found that two diterpine ester analogs of ryanodine, designated A and B, each cause only one of the effects of ryanodine. Therefore, these compounds may selectively increase and decrease a SR membrane calcium permeability and perhaps activate and inhibit the calcium release channel. 1. We will extract and purify the following compounds from Ryania wood: Ryanodine, dehydroryanodine, and the diterpine esters designated A, B, C1, C2 and D. In addition, ryanodine will be chemically modified to form 9-epiryanodine, isodehydroryanodine, anhydroryanodine, oxoryanodine, ryanodol and pyrrole-2-carboxylic acid. 2. In a series of in vitro investigations we will establish and compare the effects of ryanodine and its analogs on passive and active calcium fluxes across, and calcium binding by, SR membranes isolated from skeletal, cardiac and smooth muscles. We will also determine the effects of these compounds on the conductance and activation characteristics of calcium channels incorporated into lipid bilayers from membrane fractions found to be affected by the alkaloids. Ineffective compounds will be tested for their ability to antagonize the actions of those compounds found to act at one of the sites affected by ryanodine. The structure-activity information obtained from these studies will be used to identify the structural features of the ryanodine molecule which are important for each activity. 3. We will determine the ability of each compound to alter the rate of oxygen consumption, cytoplasmic calcium activity and the mechanical and electrical functions of intact skeletal, cardiac and smooth muscles. We will correlate the structure-activity relationships obtained in these in situ studies with those determined in the preceding step in order to establish the cause and effect relationships existing between the in vitro changes in SR calcium movements and the alterations in intact muscle function produced by these compounds.