Fig. 4.

Analysis of Adult siMR Transgenic Rats

A, Inspection of tissue biopsies from adult transgenic and wild-type rats by fluorescent and normal light (liver; P, pancreas). B, Western blot analysis of DsRed protein expression in the kidney of four adult siMR transgenic rats. β-Tubulin (Tub) served as a loading control. C, Analysis of PRA in adult wild-type and transgenic rats expressing (tg⁺) or lacking (tg⁻) DsRed protein (upper panel). Correlation between PRA and serum aldosterone levels in adult transgenic rats (lower panel). Solid symbols represent DsRed⁻ animals, and open symbols represent DsRed⁺ rats in both panels. D, Plasma and urine concentrations of Na⁺ (left y-axis) and K⁺ (right y-axis) were determined in adult wild-type and DsRed-expressing transgenic rats (n = 3 for wild type and n = 6–8 for transgenic). E, The fractional excretion of sodium (FE_Na+) was determined in adult wild-type and DsRed-expressing transgenic rats before and 3 h after amiloride injection (n = 6 for wild type and n = 4 for transgenic). Statistical analysis in all panels was performed by Student’s t test or linear regression. *, P < 0.05; **, P < 0.01; n.s., not significant (n.s., P > 0.05). r², correlation coefficient; tg, transgenic; wt, wild type.