Long-Term Effect of Nitric Oxide Inhibition on NA Transporter Abundance in Kidney: A Targeted Proteomics Approach.
Short term effects of nitric oxide (NO) on renal Na transport are well described, but long-term effects have not been investigated. To assess the role of NO on long-term regulation of Na transporter abundance along the renal tubule, we have applied a “targeted proteomics” approach. This approach uses an array of peptide-directed polyclonal antibodies to each of the major apical Na transporters and aquaporins to assess renal abundance changes in response to a given in vivo stimulus. Rats (n=6) were treated for 3 days with 30mg/kg NG-nitro-L-arginine (L-NAME), a non-selective NO synthase inhibitor, via osmotic mini-pump, while controls (n=6) received vehicle infusion. Readout was via semiquantitative immunoblotting. The table indicates the percent changes in band density in whole kidney samples for each protein target. Similar results were seen in cortical samples from the same rats, and in additional rats with identical treatment. We conclude that long-term inhibition of NO synthase with L-NAME results in a selective increase in the abundance of NCC, the thiazide-sensitive Na-Cl transporter of the distal convoluted tubule.