Treistman S N, Grant A J
Worcester Foundation for Expermental Biology, Shrewsbury, Massachusetts 01545.
Alcohol Clin Exp Res. 1990 Aug;14(4):595-9. doi: 10.1111/j.1530-0277.1990.tb01208.x.
We describe two subtypes of transient potassium current IA, found in two identified cells within the nervous system of Aplysia. These subtypes of IA are differentially sensitive to ethanol, since the decay of current is significantly slowed in the presence of ethanol in one cell, while IA is unaffected by ethanol at the same concentrations in the other cell. In this paper, we examine a number of parameters including temperature sensitivity of these different IAS. While both currents fulfill the criteria for being called IA, they are significantly different with respect to the kinetics of activation and inactivation as well as recovery from inactivation. They do not differ significantly in the temperature sensitivity of a number of measured parameters, suggesting that ethanol and temperature do not act as a common locus; e.g., by affecting a bulk lipid membrane fluidity. In light of recent work describing the molecular biology of channels underlying IA, it is reasonable to assume that these IA subtypes reflect different underlying channels. This system may be useful for understanding the relationship of channel structure and function to ethanol action.
我们描述了在海兔神经系统中两个已确定细胞内发现的两种瞬时钾电流IA的亚型。这些IA亚型对乙醇的敏感性不同，因为在一个细胞中，乙醇存在时电流的衰减明显减慢，而在另一个细胞中，相同浓度的乙醇对IA没有影响。在本文中，我们研究了许多参数，包括这些不同IA的温度敏感性。虽然两种电流都符合被称为IA的标准，但它们在激活、失活以及从失活中恢复的动力学方面存在显著差异。它们在许多测量参数的温度敏感性方面没有显著差异，这表明乙醇和温度并非作用于共同位点；例如，不是通过影响整体脂质膜流动性。鉴于最近描述IA基础通道分子生物学的研究工作，合理推测这些IA亚型反映了不同的基础通道。该系统可能有助于理解通道结构和功能与乙醇作用之间的关系。
