title: Activation of angiotensin II type 1 receptors increases D4dopamine receptor expression in rat renal proximal tubule cells.
abstract: Both the dopaminergic and renin-angiotensin systems play important roles in the regulation of blood pressure. Our previous study showed that the stimulation of dopaminergic D4receptors reduced angiotensin II type 1 (AT1) receptor expression in renal proximal tubule (RPT) cells. In this study, we tested whether AT1receptors, in return, would regulate D4receptor expression and function in RPT cells. Expression of the D4receptor from Wistar-Kyoto (WKY) or spontaneously hypertensive rats (SHRs) RPT cells and renal cortex tissues were determined by western blot, and Na+-K+ATPase activity was determined using an enzyme assay. Urine volume and urine sodium of WKY rats and SHRs treated with or without D4receptor stimulation were measured. Thus, activation of AT1receptors with angiotensin II (Ang II) increased D4receptor protein expression in RPT cells, and this increase was blocked by nicardipine, a calcium influx blocker. The D4receptor agonist PD168077 inhibited Na+-K+ATPase activity in WKY RPT cells but not in SHR RPT cells. Ang II pre-treatment promoted D4receptor-mediated inhibition of Na+-K+ATPase in RPT cells in WKY rats but not in SHRs. Meanwhile, Ang II pre-treatment augmented the natriuretic effect of PD168077 in WKY rats but not in SHRs. In conclusion, AT1stimulation can regulate the expression and natriuretic function of dopaminergic D4receptors in RPT cells and might be involved in the pathogenesis of essential hypertension.
authors.affiliation: Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Cardiovascular Clinical Research Center, Daping Hospital, Third Military Medical University, Chongqing, PR China.
authors.forename: Luxun
authors.initials: L
authors.lastname: Tang
authors.affiliation: Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Cardiovascular Clinical Research Center, Daping Hospital, Third Military Medical University, Chongqing, PR China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Zheng
authors.affiliation: Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Cardiovascular Clinical Research Center, Daping Hospital, Third Military Medical University, Chongqing, PR China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Ren
authors.affiliation: Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Cardiovascular Clinical Research Center, Daping Hospital, Third Military Medical University, Chongqing, PR China.
authors.forename: Duofen
authors.initials: D
authors.lastname: He
authors.affiliation: Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Cardiovascular Clinical Research Center, Daping Hospital, Third Military Medical University, Chongqing, PR China.
authors.forename: Chunyu
authors.initials: C
authors.lastname: Zeng
authors.affiliation: Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, PR China.|Chongqing Cardiovascular Clinical Research Center, Daping Hospital, Third Military Medical University, Chongqing, PR China.
authors.forename: Wei Eric
authors.initials: WE
authors.lastname: Wang
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D007687:Kidney Tubules, Proximal / Q000737:chemistry*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D044140:Receptor, Angiotensin, Type 1 / Q000502:physiology*; D050638:Receptors, Dopamine D4 / Q000032:analysis*
chemical_list: D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D050638:Receptors, Dopamine D4; D002118:Calcium