Evidence has been presented recently which suggests that the sodium ion is essential for the active transport' of a variety of organic solutes. This requirement was first demonstrated by Riklis and Quastel (1) who showed that Na+ was needed for the active transport of sugars by guinea pig in- testine. Subsequently, Csaky and Zollicoffer (2, 3), using rat and toad intestinal preparations, reported that Nat was required for the active transport of the monosaccharides glucose and 3-0-methylglucose, the amino acids L-tyrosine and DL-phenylalanine, and the pyrimidine, uracil. Crane, Miller, and Bihler (4, 5) also observed an obligatory Na+ requirement for active sugar trans- port by intestinal epithelium, and more recently, Kleinzeller and Kotyk (6) reported a similar re- quirement for the active transport of galactose by renal tubular epithelium.
No takes yet. Share an insight, caveat, or question.
Parrish et al. (1964) studied this question.