Kidney microcirculation response to adenosine stimulation in renal artery stenosis.

The purpose of this study was to assess the vasoconstrictive effects of adenosine in the kidney microcirculation in hypertensive patients with renal artery stenosis (RAS). Twelve patients with resistant hypertension and moderate RAS were selected for the study. In all patients, systolic, diastolic and mean translesional pressure gradients, distal pressure (Pd), aortic pressure (Pa) and Pd/Pa ratio were measured using a pressure guidewire at baseline and after intrarenal bolus administration of 400 µg adenosine. We observed significant changes in mean translesional pressure gradient and systolic Pd after pharmacological stimulation. The results suggest that in hypertensive patients with RAS, vasomotor activity of the kidney microcirculation may be preserved.

Effect of Sleep Bruxism Intensity on Blood Pressure in Normotensives.

The present research aimed to investigate the influence of sleep bruxism (SB) intensity on blood pressure parameters in normotensive subjects by using an ambulatory blood pressure device. The study group included 65 normotensive individuals suspected of having SB. All participants underwent one-night video-polysomnography, and ambulatory blood pressure monitoring was performed the next day; 86.15% of them were diagnosed with SB. Statistical analysis included correlation and regression analysis. The obtained results showed that systolic blood pressure variability during sleep significantly increased in individuals with BEI > 4 (bruxism episodes index; episodes/hour) compared to those with BEI ≤ 4 (8.81 ± 3.36 versus 10.57 ± 3.39, p = 0.05). Multivariable regression analysis showed that systolic blood pressure variability at nighttime was also associated with the following independent risk factors: higher apnea-to-bruxism index, male gender, BEI > 4 episodes/hour, body mass index (BMI) ≥ 25 kg/m2, higher arousal index, and shorter total sleep time. In summary, sleep bruxism intensity was associated with increased systolic blood pressure variability during sleep. Coincidental apnea, male gender, severe sleep bruxism (SB intensity with BEI > 4/hour), excess weight and obesity, higher arousal index, and shorter sleep time seem to be the main determinants that influence blood pressure in normotensive sleep bruxers.

Genetic aspects of primary hyperaldosteronism.

Primary hyperaldosteronism (PHA) is the most common form of secondary hypertension of hormonal origin. It affects about 10% of all hypertensive patients. It is connected with increased morbidity and mortality from cardiovascular diseases (CVD) compared to patients with essential hypertension of a similar age. Usually, it is an effect of bilateral adrenal hyperplasia (BAH) or aldosterone-producing adenoma (APA), more rare causes of PHA are: unilateral adrenal hyperplasia, aldosterone-producing adrenocortical carcinoma, ectopic aldosterone-producing tumors and familial hyperaldosteronism. Recent genetic studies have thrown a new light on the pathogenesis of PHA, classifying it as a channelopathy. Several mutations within the ion channels encoding genes have been identified. A possible link between primary hyperaldosteronism and polymorphism of aldosterone synthase gene and ion channel genes is still being investigated. In this manuscript, we focus on genetic aspects of primary hyperaldosteronism, and present an up-to-date compilation of available data with the widened pathogenetic approach.

The relationship between selected VDR, HFE and ALAD gene polymorphisms and several basic toxicological parameters among persons occupationally exposed to lead.

UNLABELLED: The aim of this study was to find a relationship between polymorphisms of ALAD rs1805313, rs222808, rs1139488, VDR FokI and HFE C282Y and H63D and basic toxicological parameters (lead and ZnPP blood concentration) in people occupationally exposed to lead. We collected data of 101 workers (age 25-63 years) directly exposed to lead. The toxicological lab tests included blood lead, cadmium and ZnPP concentration measurement and arsenic urine concentration measurement. Workers were genotyped for ALAD (rs1805313, rs222808, rs1139488), HFE (C282Y, H63D) and VDR (FokI). Individuals with the lead exposure and coexisting F allel in the locus Fok-I of VDR gene are suspected of higher zinc protoporphyrins concentrations. Workers exposed to the lead with the Y allel in the locus C282Y of the HFE gene are predisposed to lower ZnPP levels and individuals with coexisting H allel in the locus H63D HFE gene are predisposed to lower Pb-B levels. The T allel in the locus rs1805313 of the ALAD gene determines lower Pb-B and ZnPP levels in lead-exposed individuals. The heterozigosity of the locus rs2228083 of the ALAD gene has a strong predilection to higher Pb-B levels. The carriage of the C allel in the locus rs1139488 of the ALAD gene might determine higher Pb-B levels and the heterozigosity of the locus rs1139488 of the ALAD gene might result in higher ZnPP levels. CONCLUSION: The study revealed relationship between VDR, HFE and ALAD genes polymorphism and basic toxicological parameters in occupationally exposed workers.

Comparison of the renal hyperemic effects of papaverine and dopamine in patients with renal artery stenosis.

The purpose of this study was to assess the hyperemic effects of papaverine and dopamine in the renal microcirculation of hypertensive patients with renal artery stenosis (RAS). Although a poor correlation between angiographic lesion assessment and its hemodynamic significance is known, angiography is a major criterion for the decision of renal artery stenting. Assessment of the hyperemic translesional pressure gradient was recently shown to be conducive in identifying patients who may benefit from renal revascularization. The study included 14 patients (mean age, 66 ± 11.2 years) with resistant hypertension and moderate RAS. Using a pressure-sensing catheter, systolic, diastolic, and mean translesional pressure gradients, and the distal pressure (Pd):aortic pressure (Pa) ratio (Pd/Pa) were analyzed at baseline and after administration of 40 mg papaverine and 50 µg/kg dopamine. We did not observe significant changes in DG. Dopamine administration resulted in significant changes in systolic and mean translesional pressure gradients and Pd/Pa when compared with baseline (P < .05 for all). Changes in these parameters were caused by a decrease in systolic Pd in comparison with baseline conditions (119 ± 34 mm Hg vs. 101 mm Hg; P < .05). Systolic Pd pressure after papaverine (104 mm Hg) did not change significantly. Systolic and diastolic Pa values did not differ from baseline after either dopamine or papaverine bolus administration.This study indicates that, compared with papaverine, the intrarenal bolus of dopamine in hypertensive patients with RAS remains a more powerful hyperemic agent.