Immunocytochemical localization of nerve growth factor in mouse kidney

The presence of NGF in mouse kidney was investigated using immunocytochemical methods. Female and male adult Swiss-Webster mouse kidneys were fixed by perfusion with 4% paraformaldehyde or Zamboni's fixative. The kidneys were frozen, and serial sections were prepared. Rabbit NGF antiserum was used for the primary incubation, and the avidin-biotin complex immunoperoxidase procedure was utilized for immunostaining. NGF immunoreactivity was localized in the apical and perinuclear cytoplasm of cells lining the late distal nephron, in a portion that corresponds to the connecting tubule. This portion of the nephron has been consistently observed in close anatomical relationship with arterioles, which are known to be richly innervated. Some cells of the connecting tubule, corresponding to intercalated cells, lacked NGF immunoreactivity.