Figure 5: In vitro and in vivo characterization of MQ1-K39A. Competitive inhibition of AVP-induced cAMP production in stable CHO-hV2R of MQ1 (A) and MQ1-K39A (B) .(C) Corresponding Arunlakshana–Schild plots. Schild representations are plotted as mean ± SEM, n = 4 (MQ1, red) or 5 (MQ1-K39A, blue). (D) Cumulated 24 h rat diuresis after administration by i.p. route. Black: Vehicle. Red: 3 nmol/kg BW of MQ1, Blue: 3 nmol/kg BW of MQ1-K39A, n = 6. (E) Rat diuresis versus time post-injection at 3 nmol/kg BW. Same color code. (F)Representative binding competition curves of MQ1 (red) and MQ1-K39A (blue) on hV2R (full line) and rV2R (dashed line, n = 3), expressed as mean ± SEM.