Effect of angiotensin II (Ang II), angiotensin III (Ang III), angiotensin IV (Ang IV) and angiotensin-(1–7) (Ang-(1–7)) on the stimulation-induced overflow of tritium from mouse atria. The preparations were stimulated for six periods (S1–S6, 120 p, 3 Hz), delivered 18 min apart. Angiotensin was introduced into the PSS in increasing concentrations, 12 min before S2, S3, S4, S5 and S6. The symbols represent the mean percentage increase, calculated from Sn/S1 values and corrected for changes observed in control experiments in the absence of agonists. The vertical lines represent the s.e.mean from 4–27 preparations.