Acid pH increases the stability of BSC1/NKCC2 mRNA in the medullary thick ascending limb.

Chronic metabolic acidosis enhances the ability of the medullary thick ascending limb (MTAL) to absorb NH(4)(+) at least in part by stimulating the mRNA and protein expression of BSC1/NKCC2, the MTAL apical Na(+)-K(+)(NH(4)(+))-2Cl(-) co-transporter. For assessing the mechanism by which an acid pH enhances the BSC1 mRNA abundance, MTAL were harvested from adrenalectomized rats and incubated in control (pH 7.35) and acid (pH 7.