The antibody binding was visualized with the help of EnVision (+) HRP Kit (K4007 for mouse and K4011 for rabbit antibodies; Dako Denmark A/S Produktionsvej 42, DK-2600 Glostrup, Denmark) containing Labelled Polymer-HRP. Vector QS hematoxylin was used (2–3 s) for cellular nuclei staining. Negative control was carried out by incubating sections with normal rabbit and mouse serum (Confirm Negative Control Rabbit Ig Nr 760- 1029, Mouse 760-2014, Ventana) instead of primary antiserum. All the performed control reactions gave negative results (no staining). Positive control was conducted for specific tissue recommended by the producer, which is human pylorus for rat gastrin, rat brain for SY and rat atrium for rat ANP.