Cl-/base exchange in rat mesangial cells: regulation of intracellular pH.
The present study was designed to determine whether rat glomerular mesangial cells possess Cl- -dependent intracellular pH (pHi) regulatory processes. Rat glomerular mesangial cells were grown to confluence on glass coverslips. Intracellular pH (pHi) was measured with BCECF. Steady state pHi in HCO3- containing solutions was 7.08 +/- 0.03 (N = 13). When extracellular Cl- was acutely removed, pHi increased at a rate of 0.57 +/- 0.03 pH/min units (N = 8), P less than 0.001. DIDS (0.5 mM) significantly decreased the rate of increase in pHi to 0.34 +/- 0.04 pH/min, P less than 0.01. Na+ removal and amiloride (1 mM) did not alter the increase in pHi induced by Cl- removal. Steady state pHi in the absence of Cl- was significantly increased above control, 7.39 +/- 0.02 (N = 7), P less than 0.001. Following the acute alkalinization of pHi by CO2 removal, pHi recovered at a rate of 0.07 +/- 0.01 pH/min (N = 9). In the absence of Cl-, the pHi recovery rate was significantly decreased to 0.01 +/- 0.008 pH/min (N = 5), P less than 0.01. DIDS (0.5 mM) significantly decreased the rate of pHi recovery to 0.02 +/- 0.01 pH/min (N = 5), P less than 0.01. Na+ removal and amiloride (1 mM) had no effect on the rate of pHi recovery following acute alkaline loading.(ABSTRACT TRUNCATED AT 250 WORDS)
Ferdows
M
M
Department of Medicine, UCLA School of Medicine.
Golchini
K
K
Adler
S G
SG
Kurtz
I
I
D000136:Acid-Base Equilibrium; D000818:Animals; D017920:Antiporters; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism*; D005920:Glomerular Mesangium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D017920:Antiporters; D002352:Carrier Proteins; D018118:Chloride Channels; D002712:Chlorides; D007473:Ion Channels; D008565:Membrane Proteins