PHARMACOLOGY OF RYANODINE AND THE SR CA CHANNEL

实验的目的首先是确定 Ryanodine和Ryanodine的一系列结构类似物对钙离子 分离的SR膜的渗透性和钙结合特性 骨骼肌、心肌和血管平滑肌。 第二，我们将确定 这些化合物的作用的生理后果， 表征它们在完整肌肉功能中产生的变化 准备工作 在初步研究中，我们发现，两个二萜品 Ryanodine的酯类似物，命名为A和B，每一种都只引起一种 Ryanodine的作用 因此，这些化合物可以选择性地增加 并降低SR膜钙渗透性， 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： Ryanodine、Aoryanodine和指定为A、B、C1、 C2和D. 此外，ryanodine将被化学修饰， 9-表矢车菊碱，异矢车菊碱，脱水矢车菊碱，氧代矢车菊碱， ryanodol和吡咯-2-羧酸。 2.在一系列体外研究中，我们将建立并比较 兰尼碱及其类似物对被动和主动钙流的影响 和钙结合，从骨骼肌分离的SR膜， 心脏和平滑肌。 我们还将确定这些影响 化合物对钙离子电导和活化特性的影响 通道纳入脂质双层从膜馏分发现， 会受到生物碱的影响 将对无效化合物进行检测， 它们拮抗那些化合物的作用的能力被发现在 其中一个被ryanodine感染的地方 构效信息 从这些研究中获得的数据将用于识别结构 对每种活性都很重要的ryanodine分子的特征。 3.我们将确定每种化合物改变 氧消耗，细胞质钙活性和机械和 完整的骨骼肌、心肌和平滑肌的电功能。 我们 将这些中获得的结构-活性关系关联起来 现场研究与前一步骤中确定的那些，以便 建立体外细胞与细胞间的因果关系， SR钙运动的变化和完整肌肉的变化 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.