. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954 . mV 20 NUTRIENT SOLUTION- HCOa-Free Saline 100 % 02 Fig. Id (left). The bar diagram indicates the rate of H^ secretion, the ordinate; of the two halves (A & B) of a mucosa which were alternately exposed to 5% CO2 for 6 consecu- tive hour periods, given as the abscissa. The curves below follow the mean spontaneous po- tential in mv, the ordinate, for the corresponding 6 hour periods. Fig. lb [right). Effect of 'Diamox' on
. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954 . mV 20 NUTRIENT SOLUTION- HCOa-Free Saline 100 % 02 Fig. Id (left). The bar diagram indicates the rate of H^ secretion, the ordinate; of the two halves (A & B) of a mucosa which were alternately exposed to 5% CO2 for 6 consecu- tive hour periods, given as the abscissa. The curves below follow the mean spontaneous po- tential in mv, the ordinate, for the corresponding 6 hour periods. Fig. lb [right). Effect of 'Diamox' on hydrogen ion secretion and spontaneous potential of two halves of a mucosa (A & B) during 6 hour periods, with complete recovery of the potential after removal of the inhibitor. The bar diagram and curves are based on the convention used in figure la. The incomplete bars on the extreme left and right indicate control H"*" secretion in the absence of Diamox. The H^ increase elicited by exposure of the secretory surface to 5% CO2 is less when the nutrient surface is continuously exposed to CO2 and HCOs". The portions of the potential curves corresponding to these control values of H+ secretion indicate the extent of the inhibition and recovery after 6 hours of exposure to the carbonic anhydrase inhibitor. posure to the drug. Higher concentrations of Diamox have not been studied as 10 mM/1. is close to the limit of solubility. In a series of experiments detailed in table 2, the responses of the chloride fluxes of the isolated frog mucosa to 'Diamox' were measured. This carbonic anhydrase inhibitor modifies the chloride flux in the direction of its active trans- port, decreasing the net transport by some 60%. Interestingly enough, the inhibition of net chloride transport, short-circuit current and spontaneous potential could, in large measure, be reversed by exposing the mucosal surface to bicarbonate. In the absence of Diamox, introduction of bicarbonate into
Size: 3111px × 1606px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectelectrolytes, booksubjectphysiologyc
