Changes in the expression of α1B-adrenoceptor in peripheral mononuclear cells correlates with blood pressure and plasmatic homocysteine.

Human peripheral mononuclear cells (HPMC) have been suggested as a practical surrogate for myocardial or vascular cells. Present work analyses if changes in the expression of α1-adrenoceptors (ARs) in HPMC are related to the hypertensive state and its clinical consequences. Quantitative RT-PCR was employed to evaluate the mRNA levels of the three α1-ARs (α1A, α1B, α1D) in HPMC isolated from normotensive and hypertensive patients, and also in tissues from two animal models of hypertension: spontaneously hypertensive rats (SHR) and hypertension induced by chronic treatment with L-NAME. In patients, 24-h ambulatory blood pressure and serum biochemical profile were also recorded. We found that α1B-AR expression was higher in HPMC from hypertensive patients and correlated with blood pressure and plasmatic homocysteine. A rise in the α1B-AR expression in kidneys, but not in heart from hypertensive animal models was also found. α1D-AR did not change in HPMC, not in rat heart or kidney, but a significant correlation with plasmatic aldosterone was found. In conclusion, we have proved that α1-ARs mRNA expression in HPMC correlates with clinical variables and could be used as a potential biomarker in hypertensive patients.

ß2- and ß1-Adrenoceptor Expression Exhibits a Common Regulatory Pattern With GRK2 and GRK5 in Human and Animal Models of Cardiovascular Diseases.

To explore if genic expression of ß(1)- or ß(2)-adrenoceptors (ARs) exhibits a common regulatory pattern with G protein-coupled receptor kinase (GRK) 2, GRK3, or GRK5 expression, we determined messenger RNA levels for these genes in different tissues from human and animal models of cardiovascular disease. We measured genic expression by qRT polymerase chain reaction in the left and right ventricles or peripheral blood mononuclear cells from healthy (n = 21), hypertensive (n = 20), heart failure (n = 24), and heart transplanted patients (n = 17) or in left ventricle, peripheral blood mononuclear cells, and kidney from spontaneously hypertensive rats or L-N-methyl-arginine-induced hypertensive rats and their respective controls (n = 4-5). In diseased versus healthy subjects and rats, parallel changes in messenger RNA levels of GRK2 and ß(2)-AR or GRK5 and ß(1)-AR were observed in each territory. Therefore, without excluding other regulatory mechanisms, the parallelism observed suggests a common regulatory pattern for the ß(1)-AR/GRK5 and ß(2)-AR/GRK2 genes, which is independent of cellular type or pathology. This highlights the need to focus not only on GRKs but also on ß(1)- or ß(2)-AR changes to completely understand the involvement of ß-AR/GRK pathways in cardiovascular diseases.

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. RESULTS AND 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.

Cateterización bilateral de los senos petrosos inferiores: utilidad en el síndrome de cushing / Bilateral catheterization of inferior petrosal sinous: utility in cushing’ syndrome

Objetivo: Presentar la experiencia de los autores en el cateterismo bilateral y simultáneo de los senos petrosos inferiores (SPI) en pacientes con síndrome de Cushing dependientes de la hormona adrenocorticotropa (ACTH ). Material y método: Un estudio retrospectivo desde enero de 2003 hasta septiembre de 2009 con nueve pacientes (dos hombres y siete mujeres) diagnosticados con síndrome de Cushing y ACTH dependientes. Se cateterizaron simultáneamente los senos petrosos inferiores, estudiando la ACTH basal y tras un estímulo con la CRH, a fin de medir los gradientes intrahipofisarios y en sangre periférica. La sospecha diagnóstica se realizó por concentraciones inapropiadas y persistentemente elevadas de cortisol plasmático y del cortisol libre urinario; así como por ausencia de supresión con la dexametasona. En todos, salvo uno, las pruebas de imagen fueron negativas. Resultados: La cateterización fue exitosa y sin complicaciones. Hubo un diagnóstico definitivo en todos los casos. Conclusión: En los pacientes seleccionados, la cateterización de los SPI fue un procedimiento eficiente en el diagnóstico diferencial del síndrome de Cushing y en la localización intrahipofisaria de la secreción de ACTH.

Objective: The aim of this study is to present our experience on bilateral and simultaneous inferior petrous sinus catheterization, on those patients with ACTH -dependent Cushing’s sydrome. We describe the procedure and our results. Material and Method: A retrospective study was held between January 2003 and September 2009, including nine patients (2 men, 7 women) presenting ACTH -dependentCushing’s syndrome. Simultaneous inferior petrosal sinus catheterization was performed in all of them, sampling basal ACTH and after CRH stimulation. ACTH levels gradient in different pituitary locations and peripheral blood levels was recorded. Diagnosis was suggested when inappropriate and maintained hypercortisolemia. High urinary free cortisol levels and no response to dexamethasone suppressionwere detected. Eight out of nine patients had a prior negative imaging test result. Results: Inferior petrosal sinus bilateral catheterization was successfully performed in all cases, with no evidence of further complications. The results showed definitive diagnosis in all cases. In four patients ACTH levels gradient was lateralized to the left, leading to a specific surgical approach. One patient presented pituitary ACTH -secreting adenoma. Two other patients showed ectopic ACTH production, one showedsuprarenal adenoma secreting ACTH and other one showed response to pituitary stimulation without side lateralisation, presenting a histological diagnosis of pituitary hyperplasia. Conclusion: Petrosal sinus catheterization is shown to be an efficient procedure to manage Cushing’s syndrome differential diagnosis and to obtain specific anatomical information.

Influence of LDL receptor gene mutations and the R3500Q mutation of the apoB gene on lipoprotein phenotype of familial hypercholesterolemic patients from a South European population.

Few data are available on genotype-phenotype interactions among familial hypercholesterolemia (FH) patients in South European populations and there are no data about the influence of R3500Q mutation on lipoprotein phenotype compared to low-density lipoprotein receptor (LDLR) mutations. The objective of the study is to analyze the influence of mutations in the LDLR and apolipoprotein B (apoB) genes on lipoprotein phenotype among subjects clinically diagnosed of FH living in East Spain. In all, 113 FH index patients and 100 affected relatives were studied. Genetic diagnosis was carried out following a protocol based on Southern blot and PCR-SSCP analysis. A total of 118 FH subjects could be classified into three groups according to the type of LDLR mutations (null mutations, missense mutations affecting the ligand binding 3-5 repeat, and missense mutations outside this domain). In addition, the lipoprotein phenotype of these FH groups was compared with 19 heterozygous subjects with familial ligand-defective apoB (FDB), due to R3500Q mutation. FH patients carrying missense mutations affecting the ligand binding repeat 3-5 showed total and LDL cholesterol levels significantly higher than FH patients with missense mutations in other LDLR domains or FDB patients. FH subjects carrying null mutations showed lower high-density lipoprotein cholesterol plasma values compared to FH carrying missense mutations. FDB subjects showed the lowest total and LDL cholesterol plasma values. In conclusion, the type of LDLR gene mutation and R3500Q mutation influences the lipoprotein phenotype of FH population from East Spain.

Transdermal estradiol reduces plasma myeloperoxidase levels without affecting the LDL resistance to oxidation or the LDL particle size.

OBJECTIVE: This study was designed to investigate the effects of different therapeutic range doses of transdermal estradiol (E(2)), alone or in combination with progesterone (P) or medroxyprogesterone acetate (MPA), on plasma lipoprotein levels and on three parameters related with LDL oxidizability, the resistance of LDL to oxidation by copper, the LDL particle size, and the myeloperoxidase levels. DESIGN: Thirty-five healthy postmenopausal women who had been amenorrheic for at least 1 year received two consecutive, 2-month doses of transdermal estrogen (25-microg and 50-microg E(2) patch). Thereafter, they were randomly assigned to receive a 2-month treatment of either a 100-microg E(2) patch or a 50-microg E(2) patch combined with P (300 mg/day) or MPA (5 mg/day) during the last 14 days. RESULTS: Neither transdermal E(2) alone nor transdermal E(2) plus progestogen modified the lipoprotein profile, the LDL resistance to oxidation, or the LDL particle size. However, all treatments similarly reduced the myeloperoxidase protein levels. CONCLUSIONS: Different dosages of transdermal E(2) within the therapeutic range were equally effective in reducing myeloperoxidase protein levels. The effect remained after addition of P or MPA in a sequential regime.