Fig. 2. Expression of the vasopressin receptor in CnA knockout mice. (A,B) Expression of V₂R was visualized by immunohistochemistry in kidney sections of (A) +/+ and (B) -/- mice using the DAB chromagen and counterstaining with hematoxylin. Data are representative of at least four mice. (C) Expression of the V₂R was also determined by first immunoprecipitating with a specific antibody against the receptor and then immunoblotting with the same antibody. Lanes 1-3, +/+ mice; lanes 4-6, -/- mice. Bar graph on the right shows expression of V₂R as the mean ± s.e.m. ns, not significant.