Fig. 4.

Effect of angiotensin 1−7 (ANG 1–7) on PKG and tyrosine hydroxylase (TH) expression and activity. Renal proximal tubules were incubated with ANG 1–7 in the presence and absence of ANG 1–7 antagonist A-779, DR blocker SCH23390, PKG inhibitor KT5823, and TH inhibitor 3-iodo-l-tyrosine. Renal proximal tubular PKG activity (A) and PKA activity (B) are shown. TH expression and phosphorylation were determined by Western blot analysis (C) and ELISA (D). TH activity was determined by HPLC-MS (E). n = 6–8 rats. *P < 0.05 vs. saline by one-way ANOVA followed by a post hoc Newman-Keuls test. PKG and TH activity were assayed in quadruplicate from each rat; expression and Ser⁴⁰ phosphorylation (ELISA) were performed in quintuplicate from each rat.