Figure 1.

Histamine receptor (HR)1, HR2, HR3, and HR4 as well as histaminergic system enzymes are expressed within the renal cortex and medulla of male Dahl salt-sensitive (DSS) rats. A and B: representative images of immunohistochemical staining for histamine decarboxylase (HDC), histamine N-methyltransferase (HNMT), diamine oxidase (DAO), HR1, HR2, HR3, and HR4, respectively, within renal cortical glomeruli (magnification: ×40) and tubules (magnification: ×20) of male DSS rats fed a normal-salt diet. Scale bars = 25 µm for glomeruli and 50 µm for tubules. C: representative images of inner and outer medullary expression of HDC, HNMT, DAO, HR1, HR2, HR3, and HR4 in normal-salt diet-fed DSS rats. Scale bar = 50 µm. The brown coloration represents expression. Scale bars shown in the negative control image apply to all images within the same group.