Serum NT-proANP levels at prestudy, Days 2 and 8 in rats treated with vehicle control, 7-daily oral doses of MNX at 30 mg/kg/day or a single subcutaneous dose of ISO at 5 mg/kg, analyzed by (A) MSD kit at SRI, and (B) MSD or Alpco kits at Lilly (B, MSD; C, Alpco). Values are means, SD as error bars; n=5. **Significantly different from the concurrent vehicle control, p-value<0.01; ***p-value<0.001.