Effects of glucose on water and sodium reabsorption in the proximal convoluted tubule of rat kidney.

Publisher Website
Google Scholar
Abstract
Effects of glucose on Na and water reabsorption by rat renal proximal tubules was investigated by in situ microperfusion of segments of proximal tubules with solutions containing glucose or no glucose, with and without phlorizin. Absence of glucose did not significantly alter net water flux. Na flux was reduced by about 10%, but this was not statistically significant. In the absence of glucose in the perfusion fluid net secretion of glucose occurred. Phlorizin reduced either net reabsorption or net secretion of glucose, and net water flux. In later parts of the proximal convoluted tubule some Na may be co-transported with glucose, but that this represents only a small fraction of total Na reabsorption. The glucose carrier was reversible and in appropriate circumstances may cause glucose secretion. Although phlorizin altered net water flux, the underlying mechanisms were not clear. Calculated osmolality of the reabsorbate was significantly greater than perfusate osmolality and greater than plasma osmolality, although this was not quite statistically significant.