Dopamine D1-like receptors regulate the α1A-adrenergic receptor in human renal proximal tubule cells and D1-like dopamine receptor knockout mice
American Journal of Physiology - Renal Physiology
Adrenergic receptor; Dopamine receptor; Knockout mice; Renal proximal tubule cells; Sodium transport
© 2014 the American Physiological Society. The homeostatic control of blood pressure hinges upon the delicate balance between prohypertensinogenic and antihypertensinogenic systems. D1-like dopamine receptors [dopamine D1 and D5 receptors (D1Rs and D5Rs, respectively)] and the a1A-adrenergic receptor (α1A-AR) are expressed in the renal proximal tubule and engender opposing effects on Na+ transport, i.e., natriuresis (via D1Rs and D5Rs) or antinatriuresis (via α1A-ARs). We tested the hypothesis that the D1R/D5R regulates the α1A-AR. D1-like dopamine receptors coimmunoprecipitated, colocalized, and cofractionated with ct1A-ARs in lipid rafts in immortalized human renal proximal tubule cells. Long-term treatment with the D1R/D5R agonist fenoldopam resulted in decreased D1R and D5R expression but increased α1A-AR abundance in the plasma membrane. Short-term fenoldopam treatment stimulated the translocation of Na+-K+-ATPase from the plasma membrane to the cytosol that was partially reversed by an α1A-AR agonist, which by itself induced Na+-K+-ATPase translocation from the cytosol to the plasma membrane. The a1A-AR-specific agonist A610603 also minimized the ability of fenoldopam to inhibit Na+-K+-ATPase activity. To determine the interaction among D1Rs, D5Rs, and α1A-ARs in vivo, we used phenylephrine and A610603 to decrease Na+ excretion in several D1-like dopamine receptor knockout mouse strains. Phenylephrine and A61603 treatment resulted in a partial reduction of urinary Na+ excretion in wild-type mice and its abolition in D1R knockout, D5R knockout, and D1R-D5R double-knockout mice. Our results demonstrate the ability of the D1-like dopamine receptors to regulate the expression and activity of α1A-AR. Elucidating the intricacies of the interaction among these receptors is crucial for a better understanding of the crosstalk between anti- and pro-hypertensive systems.
Ennis, R., Asico, L., Armando, I., Yang, J., Feranil, J., Jurgens, J., Escano, C., Yu, P., Wang, X., Sibley, D., Jose, P., & Villar, V. (2014). Dopamine D1-like receptors regulate the α1A-adrenergic receptor in human renal proximal tubule cells and D1-like dopamine receptor knockout mice. American Journal of Physiology - Renal Physiology, 307 (11). http://dx.doi.org/10.1152/ajprenal.00119.2014