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Increased Na/H antiporter activity has been demonstrated after in vivo chronic metabolic acidosis as well as in vitro acid preincubation of cultured rabbit renal tubule cells. To study the underlying molecular mechanisms of this adaptive increase in Na/H antiporter activity, the present studies examined the effect of low pH media on Na/H antiporter activity and mRNA abundance in cultured renal tubule cells. Na/H antiporter activity was increased by 60% in a mouse renal cortical tubule cell line (MCT), and by 90% in an opossum kidney cell line (OKP) after 24 h of preincubation in acid (low [HCO3]) media. The ethylisopropylamiloride sensitivity of the Na/H antiporters were different in these two cell lines (MCT IC50 = 65 nM; OKP IC50 = 4.5 microM). In MCT cells, Na/H antiporter mRNA abundance measured by RNA blots increased by two- to fivefold after 24 h in low [HCO3] media. Na/H antiporter mRNA abundance was also increased in MCT cells with high CO2 preincubation as well as in rat renal cortex with in vivo chronic acid feeding. In contrast to renal epithelia, acid preincubation of NIH 3T3 fibroblasts led to suppression of Na/H antiporter activity. RNA blots of 3T3 fibroblasts revealed the same size Na/H antiporter transcript as in MCT cells. However, Na/H antiporter mRNA levels were suppressed by acid preincubation. These studies demonstrate differential regulation of Na/H antiporter activity and mRNA abundance in renal epithelial cells and fibroblasts in response to an acidotic environment.
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
April 1996,
Journal of hepatology,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
January 1997,
The Journal of experimental biology,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
November 1990,
The Journal of biological chemistry,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
August 1999,
Anesthesia and analgesia,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
June 1990,
Proceedings of the National Academy of Sciences of the United States of America,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
October 1991,
The American journal of physiology,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
July 1994,
The American journal of physiology,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
September 1992,
Nihon rinsho. Japanese journal of clinical medicine,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
November 1983,
The Journal of biological chemistry,
O W Moe, and
R T Miller, and
S Horie, and
A Cano, and
P A Preisig, and
R J Alpern
June 1993,
The American journal of physiology,
