The effect of uranyl nitrate on intestinal transfer of hexoses.

1. Uranyl nitrate in a concentration of 3 x 10(-4)M caused reduction in mucosal transfer of glucose but not of galactose nor 3-O-methyl-glucose by sacs of rat everted intestine. At this concentration uranyl nitrate had little effect on glucose metabolism (measured by glucose disappearance).2. Uranyl nitrate in a concentration of 3 x 10(-3)M caused reduction in transfer of glucose, galactose, 3-O-methyl-glucose and fluid, and inhibited glucose metabolism.3. Uranyl nitrate did not inhibit entry of glucose into the intestine under anaerobic conditions.4. Glucose was found to inhibit or stimulate galactose transfer depending on the conditions. The inhibitory action is presumably by competition for a common carrier, whereas stimulation indicates that glucose metabolism can supply energy for galactose transfer.5. It is suggested that there are two different routes for glucose in the cell, one of which is uranyl sensitive and not used by galactose, and the other is uranyl insensitive and shared by both hexoses. The implications of this are discussed in relation to transport and metabolism.