Figure 1.

In situ hybridization for ET_B mRNA in the kidney of wild-type and DBH-ET_B;ET_Bsl/sl adult rats. Low-power (a and c) and high-power (b and d) magnification of cross-sections of the renal cortex demonstrate strong hybridization signal for ET_B mRNA in the glomeruli and the associated cortical tubule and vascular structures in wild-type rats (a and b). This signal is absent in the DBH-ET_B;ET_Bsl/sl rats (c and d). Arrows indicate representative glomeruli. Findings were similar, though less dramatic, in the renal medulla (data not shown).