EFFECT OF THERAPY ON SICKLE CELL HYDRATION AND SURVIVAL

网织红细胞和其他年轻红细胞对 镰状细胞病的溶血和血管闭塞方面变得更多 这在最近几年是显而易见的。同时，有效的治疗策略 (羟基脲)和有希望的实验试剂(克霉唑)已经成为 可用。这些因素导致了根本性但鲜为人知的变化。 在镰状细胞的行为中。在拟议的研究中，研究将是 以更好地了解与时间相关的细胞变化 发生在循环中的镰状细胞中，细胞年龄和HBF含量在 确定这些变化，以及镰状细胞行为的改变 这是有效治疗的结果。三类实验 将执行：1)详细的RBC亚群的体外分析 密度分数。这些实验将揭示出 脱水作为年龄和HbF含量的函数，以及 这些细胞亚型在治疗过程中的行为；2)调查 导致年轻和成熟红细胞脱水的运输途径 在有氧和脱氧条件下，以及这些酶活性的变化 治疗途径；3)在体内，生物素的多参数跟踪- 标记的自体镰状细胞以确定存活和时间- 红细胞亚群的依赖性水化变化、细胞年龄和 Hbf，以及有效治疗后发生的变化。被观察到的 治疗前后的红细胞行为将在 镰状细胞脱水和存活的综合模型的背景。 在这个模型中，网织红细胞的初始脱水取决于 CI共转运途径对K外流的活性并不依赖于 脱氧和HBF，而脱水的晚期是镰刀状的 依赖，其中HBF起着重要作用。这些调查将 更好地了解镰状细胞的病理生理学，定义 由于有效治疗而发生的细胞变化，以及 提供必要的信息以制定改进的治疗方案 战略。

The contribution of reticulocytes and other young RBC toward both the hemolytic and vasocclusive aspects of sickle cells disease has become more apparent in recent years. At the same time, effective treatment strategies (hydroxyurea) and promising experimental agents (clotrimazole) have become available. These agents induce fundamental but poorly understood changes in the behavior of sickle cells. In the proposed research, studies will be performed to better understand the time-dependent cellular changes that occur in circulating sickle cells, the role of cell age and HbF content in determining these changes, and the modification of sickle cell behavior that occurs as a result of effective treatment. Three types of experiments will be performed: 1) Detailed in vitro analysis of RBC subpopulations in density fractions. These experiments will shed light on the extent of dehydration as a function of age and HbF content, and on changes in the behavior of these cellular subtypes with treatment; 2) Investigations of the transport pathways that lead to dehydration of young and mature RBC under oxy and deoxy conditions, and the changes in the activity of these pathways with treatment; 3) In vivo, multiparametric tracking of biotin- labeled, autologous sickle cells to determine the survival and time- dependent hydration change of RBC subtypes, the influence of cell age and HbF, and the changes that occur after effective treatment. The observed red cell behavior, before and after treatment, will be analyzed in the context of a comprehensive model of sickle cell dehydration and survival. In this model, initial reticulocyte dehydration is dependent on the activity of the CI co-transport pathway for K efflux and is independent of deoxygenation and HbF, while terminal stages of dehydration are sickling dependent, with HbF playing an important role. These investigations will provide a better understanding of sickle cell pathophysiology, define the cellular changes that occur as a result of effective treatment, and provide the information necessary to formulate improved treatment strategies.