Western blot analysis verified expression of all four histamine receptors (HRs) within the renal cortex of male Dahl salt-sensitive rats on a normal-salt (NS) vs. high-salt (HS) diet. A–D, left: Western blot analysis probing for HR1 (A), HR2 (B), HR3 (C), and HR4 (D) within the renal cortex of male Dahl salt-sensitive rats fed either a NS or HS diet. Each lane represents an individual animal. Pierce-stained membranes are shown below probed membranes. A–D, right: densitometry analysis of the Western blots shown on the left comparing HR1 (A), HR2 (B), HR3 (C), and HR4 expression (D) in the renal cortex of NS or HS diet-fed rats; n = 10 per diet group; each lane is a sample from an independent animal. Boxes indicate means ± SE; whiskers indicate SDs. One-way ANOVA with a Holm-Sidak post hoc test was used for statistical analysis; a.u. arbitrary units.