Metabolite transport at cell membranes.

Abstract

From the assigned title I am glad to assume that the organizers would like to have me discuss some general ideas of metabolite transport, rather than to try to summarize the findings specific to the nervous system, the details of which most of you may know rather better than I do. Fortunately, transport behavior seems in general to be similar among tissues, so that the history of transport ideas and findings is a single history and not one specific to each anatomical or functional field, despite occasional impressions to the contrary. I assume that the means of discrimination of distinct transport systems falls among the subjects that I might more logically discuss. That subject continues to deserve attention, because one still sees bent Lineweaver-Burk plots treated as though they were sufficient evidence for the contribution of two parallel transport systems. I feel obliged, however, not to spend much of my time in this presentation in explaining what my colleagues and I have been doing in past years to codify the several amino acid transport systems, or in indicating what the new difficulties are, or in summarizing how these codifications have so far applied to nervous tissue. Instead I want mainly to treat a theoretical problem that has come to seem to me critically restrictive to progress. I trust I can later help you with some useful thoughts on the discrimination of the several systems, as such comments may become appropriate during the discussion time.