TY - JOUR
T1 - Sodium-hydrogen exchange system in brush border membranes from cortical and medullary regions of the proximal tubule
AU - Moran, Arie
AU - Stange, Gerti
AU - Murer, Heini
N1 - Funding Information:
Science Nationalfonds foundation, (grant Jerusalem, No. 3.854.0.881. Israel , grant We are No.
PY - 1989/8/30
Y1 - 1989/8/30
N2 - The Na+/H+ exchange system was studied in brush border membrane vesicles isolated from cortical and medullary regions of the proximal tubule of rabbit kidney. The activity of the exchanger was assessed by measuring hydrogen influx (monitored by acridine orange fluorescence), 22Na influx and the sensitivity of these fluxes to amiloride and its analogue ethylisopropyl amiloride. In contrast to previously published data (indicating the absence of pH-gradient driven and amiloride sensitive 22Na-influx in medullary site vesicles (13,15)), Na+/H+ exchange activity could be detected in both membrane preparations by sodium tracer and fluorescence detection of hydrogen influx. Amiloride inhibition of 22Na influx was more effectively protected by increasing sodium concentration in cortical than in medullary vesicles, suggesting differences in the action of amiloride in these preparations.
AB - The Na+/H+ exchange system was studied in brush border membrane vesicles isolated from cortical and medullary regions of the proximal tubule of rabbit kidney. The activity of the exchanger was assessed by measuring hydrogen influx (monitored by acridine orange fluorescence), 22Na influx and the sensitivity of these fluxes to amiloride and its analogue ethylisopropyl amiloride. In contrast to previously published data (indicating the absence of pH-gradient driven and amiloride sensitive 22Na-influx in medullary site vesicles (13,15)), Na+/H+ exchange activity could be detected in both membrane preparations by sodium tracer and fluorescence detection of hydrogen influx. Amiloride inhibition of 22Na influx was more effectively protected by increasing sodium concentration in cortical than in medullary vesicles, suggesting differences in the action of amiloride in these preparations.
UR - http://www.scopus.com/inward/record.url?scp=0024467281&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(89)92131-1
DO - 10.1016/0006-291X(89)92131-1
M3 - Article
AN - SCOPUS:0024467281
SN - 0006-291X
VL - 163
SP - 269
EP - 275
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -