Effect of Cholera Toxin on Renal Tubular Reabsorption of Glucose and Bicarbonate

Publisher Website
Google Scholar
Abstract
Cholera toxin (CT) reduces tubular [dog kidney] reabsorption of Na, Cl, Ca, Mg and P most probably through stimulation of a renal adenylate cyclase-cyclic AMP system, and it is possible that an increased production of nephrogenous cyclic AMP during extracellular fluid volume expansion may be partly responsible for the observed natriuresis. In order to further evaluate the role of renal cyclic AMP in renal tubular transport, the effect of CT on glucose (TRG) and bicarbonate reabsorption (TRHCO3) was studied. During the period of maximal effect of CT on tubular transport (100-140 min of CT infusion into 1 renal artery) the TRG and TRHCO3 were lower in the infused kidney than in the contralateral noninfused kidney; TRG as mg/100 ml GFR was 254 .+-. 32.7 vs. 363 .+-. 43.5 (P < .01), and TRHCO3 as milliequivalents/100 ml GFR was 2.09 .+-. 0.06 vs. 2.53 .+-. 0.06 (P < .01). CT may supress glucose and bicarbonate reabsorption with that of Na and may assign to role for renal cyclic AMP in the regulation of the tubular transport of these substances.