beta-Adrenoceptor and GRK3 expression in human lymphocytes is related to blood pressure and urinary albumin excretion.
OBJECTIVE
The objective of our work was to analyze if changes in the expression of beta-adrenoceptors (beta-ARs) and G-protein-coupled receptor kinases (GRKs) in human lymphocytes - a practical surrogate for myocardial or vascular cells - are related to the hypertensive state and its clinical consequences.


METHODS
Real-time quantitative RT-PCR was employed to evaluate the expression of the three beta-ARs (beta1, beta2, beta3) and three GRKs (GRK2, GRK3, GRK5) in human lymphocytes obtained from both normotensive and hypertensive patients, some of whom had been treated with blockers of the renin-angiotensin system. Office blood pressure, 24-h ambulatory blood pressure, urinary albumin excretion and serum biochemical profile were also recorded.


CONCLUSIONS
beta1-AR expression levels were higher in circulating lymphocytes from hypertensive patients (2-DeltaDeltaCt = 2.135 +/- 0.4252*, vs. control group), but this difference was not observed when these patients were treated with blockers of the renin-angiotensin system. beta1-AR levels directly correlated (r2 = 0.5711, P = 0.0185) with urinary albumin excretion in microalbuminuric patients, which relates alterations of this receptor to cardiovascular risk. An inverse correlation was observed between the expression levels of beta2-AR and diastolic blood pressure (r2 = 0.2078, P = 0.0031), suggesting that beta2-AR levels in lymphocytes mirror their expression in vascular cells, in which beta2-AR-mediated relaxation regulates vascular resistance. mRNA levels for GRK3 were inversely correlated with systolic and diastolic blood pressure (day, night and 24 h), which suggests a protective role for GRK3 in the regulation of human blood pressure, as supported by previous findings in transgenic mice.
Oliver
Eduardo
E
Departamento de Farmacología, Facultad de Farmacia, Universitat de València, Valencia, Spain.
Rovira
Eduardo
E
Montó
Fermí
F
Valldecabres
Carmen
C
Julve
Raul
R
Muedra
Vicente
V
Ruiz
Nuria
N
Barettino
Domingo
D
D'Ocon
Pilar
P
D000419:Albuminuria / Q000378:metabolism*; D001794:Blood Pressure; D005260:Female; D054770:G-Protein-Coupled Receptor Kinase 3 / Q000378:metabolism*; D006801:Humans; D008214:Lymphocytes / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D011943:Receptors, Adrenergic, beta; D054770:G-Protein-Coupled Receptor Kinase 3; C517848:GRK3 protein, human