DIVERSITY OF A1-ADRENERGIC SIGNALING PATHWAYS IN HEART

α1-肾上腺素能信号转导通路在脑出血中的重要作用 心肌通过对细胞生长的调节作用得到证实。 (肥大)、收缩、变时性和能量代谢。其目的是 这项建议的目的是确定字母1中的近端台阶- 肾上腺素能信号转导通路调节肥大和 培养的新生儿心肌细胞的变时性。其优势在于 使用培养的心肌细胞进行这些研究包括 在这些细胞中，要在无血清培养液中保持几天， 并接受显微注射或转染法，允许直接 信号转导中特定步骤的实验操作 路径。具体来说，这项建议将寻求：L)确定 α1肾上腺素能受体、G蛋白的数量、类型和丰度 心肌细胞磷脂酶C亚型；2)测定 不同α1-肾上腺素能受体亚型在脑出血中的作用 调节肥大和变时性反应；3)确定 特异性G蛋白(S)在不同的α-肾上腺素能偶联中的作用 肥大和变时性反应的受体亚型；4) 确定胰岛素L、4，5-P3和二酰甘油是否为 肥大和变时性；以及5)确定 心脏发育过程中α1肾上腺素能反应性的变化。 实验方法将是首先确定潜在的蛋白质 参与α1-肾上腺素能信号转导通路，以及 然后通过显微注射或转基因来扰乱这一途径 编码这些蛋白质或蛋白质本身，并确定 这种扰动对α1-肾上腺素能介导的肥大的影响 和变时性反应。肥厚性生长将通过以下方式进行评估 监测心房特异标志物基因或蛋白的诱导 天然因子和肌球蛋白轻链-2。编年体将会是 通过使用监视节拍到节拍的钙瞬变来确定 荧光指示剂染料福拉2。 从拟议的研究中期望得到的信息将开始 阐明α-1基因多样性的分子基础 心肌中肾上腺素能受体介导的作用 发展。

The importance of alpha1-adrenergic signal transduction pathways in cardiac muscle is demonstrated by their regulatory effects on cell growth (hypertrophy), contractility, chronotropy and energy metabolism. The aim of this proposal is to determine the proximal steps in the alpha1- adrenergic signal transduction pathways that modulate hypertrophy and chronotropy in cultured, neonatal cardiac myocytes. The advantages in using cultured, cardiac myocytes for these studies include the ability of these cells to be maintained in serum-free medium for several days, and to undergo microinjection or transfection, allowing direct experimental manipulation of specific steps in the signal transduction pathway. Specifically, this proposal will seek: l) to determine the number, type and abundance of alpha1-adrenergic receptor, G protein, and phospholipase C subtypes in cardiac muscle cells; 2) to determine the contribution of the various alpha1-adrenergic receptor subtypes in mediating hypertrophic and chronotropic responses; 3) to determine the role of specific G protein(s) in coupling the distinct alpha1-adrenergic receptor subtypes to the hypertrophic and chronotropic responses; 4) to determine if Ins l,4,5-P3 and diacylglycerol are differential signals for hypertrophy and chronotropy; and 5) to determine the molecular basis for changes in alpha1-adrenergic responsiveness during cardiac development. The experimental approach will be to first identify potential proteins involved in the alpha1-adrenergic signaling transduction pathway, and then to perturb the pathway, by microinjecting or transfecting genes encoding these proteins or the proteins themselves, and determining the effect of this perturbation on alpha1-adrenergic-mediated hypertrophic and chronotropic responses. Hypertrophic growth will be assessed by monitoring the induction of specific marker genes or proteins for atrial naturietic factor and myosin light chain-2. Chronotropy will be determined by monitoring the beat-to-beat Ca2+ transients with the fluorescent indicator dye fura 2. The information expected from the proposed studies will begin to elucidate the molecular basis underlying the diversity of alpha1- adrenergic receptor-mediated effects in cardiac muscle during development.