期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1981
卷号：78
期号：3
页码：1638-1642
DOI：10.1073/pnas.78.3.1638
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Nuclear magnetic resonance techniques developed to study membrane permeability in closed membrane systems have been used to investigate transport of 5-hydroxytryptamine across the phospholipid membranes of large unilamellar vesicles. The vesicles, modeling the 5-hydroxytryptamine storage organelles of blood platelets, contained a high internal level of ATP buffered at a pH low relative to the external solution. The resultant pH gradient drove accumulation of 5-hydroxytryptamine to a level consistent with selective transport of the neutral amine. The upfield shifts of the 5-hydroxytryptamine resonances resulting from complexation with internally confined ATP were utilized to resolve and, simultaneously, to observe the internal and external amine. Simulation of the time evolution of the 5-hydroxytryptamine concentration allowed measurement of a permeability coefficient of 1.4 +/- 0.5 X 10(-5) cm/sec for the neutral amine.
