Effect of D Dopamine Receptor on Na-K-ATPase Activity in Renal Proximal Tubule Cells

Document Type

Journal Article

Publication Date



Cardiology discovery








Dopamine D4 receptor; Hypertension; Kidney; Renal proximal tubule; Sodium-potassium-exchanging ATPase


UNLABELLED: Dopamine, via its receptors, plays a vital role in the maintenance of blood pressure by modulating renal sodium transport. However, the role of the D dopamine receptor (D receptor) in renal proximal tubules (PRTs) is still unclear. This study aimed to verify the hypothesis that activation of D receptor directly inhibits the activity of the Na-K-ATPase (NKA) in RPT cells. METHODS: NKA activity, nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) levels were measured in RPT cells treated with the D receptor agonist PD168077 and/or the D receptor antagonist L745870, the NO synthase inhibitor NG-nitro-L-arginine-methyl ester (L-NAME) or the soluble guanylyl cyclase inhibitor 1H-[1,2,4] oxadiazolo-[4,3-a] quinoxalin-1-one (ODQ). Total D receptor expression and its expression in the plasma membrane were investigated by immunoblotting in RPT cells from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs). RESULTS: Activation of D receptors with PD168077, inhibited NKA activity in RPT cells from WKY rats in a concentration- and time-dependent manner. The inhibitory effect of PD168077 on NKA activity was prevented by the addition of the D receptor antagonist L745870, which by itself had no effect. The NO synthase inhibitor L-NAME and the soluble guanylyl cyclase inhibitor ODQ, which by themselves had no effect on NKA activity, eliminated the inhibitory effect of PD168077 on NKA activity. Activation of D receptors also increased NO levels in the culture medium and cGMP levels in RPT cells. However, the inhibitory effect of D receptors on NKA activity was absent in RPT cells from SHRs, which could be related to decreased plasma membrane expression of D receptors in SHR RPT cells. CONCLUSIONS: Activation of D receptors directly inhibits NKA activity via the NO/cGMP signaling pathway in RPT cells from WKY rats but not SHRs. Aberrant regulation of NKA activity in RPT cells may be involved in the pathogenesis of hypertension.