Predictive role of renal resistive index for clinical outcome after revascularization in hypertensive patients with atherosclerotic renal artery stenosis: a monocentric observational study.

BACKGROUND: The present study evaluated the predictive value of renal resistive index (RI) for renal function and blood pressure (BP) outcome in hypertensive patients with unilateral atherosclerotic renal artery stenosis submitted to successful revascularization. METHODS: In 158 hypertensive patients with atherosclerotic renal artery stenosis RI was acquired. Twelve months after revascularization, they were classified on the basis of renal function and BP outcome as benefit (BP < 140/90 mmHg or diastolic BP reduction > 15 mmHg with the same of reduced drugs; decrease in glomerular filtration rate > 20%), or failure. RESULTS: Regarding renal function outcome, RI in the stenotic and in the contralateral kidney were significantly higher in patients with failure (n = 20) than in those with benefit (0.72 ± 0.11 vs 0.61 ± 0.11 and 0.76 ± 0.08 vs 0.66 ± 0.09, p < 0.05). Among different cutpoints generated, RI in the contralateral kidney >0.73 provided the largest area under the curve (0.77), and the highest sensitivity (80%) and specificity (72%). In the multivariate logistic regression analysis, RI in the contralateral kidney >0.73 was an independent predictor of a failure in renal function outcome.Regarding BP outcome, patients with no benefit from revascularization (n = 60) had similar RI in the stenotic and contralateral kidney (p = ns), but presented higher pulse pressure, albuminuria and hypertension duration in comparison to patients with improved BP control. CONCLUSIONS: RI in the contralateral kidney is an independent predictor of renal function outcome after successful revascularization in hypertensive patients with unilateral atherosclerotic renal artery stenosis, whereas it is not able to predict blood pressure outcome.

Expression of lipoprotein-associated phospholipase A(2) in carotid artery plaques predicts long-term cardiac outcome.

AIMS: The aim was to test the hypothesis that carotid artery plaque expression of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) predicts cardiac events. METHODS AND RESULTS: Prospective cohort study of 162 consecutive patients undergoing elective carotid endarterectomy. Lipoprotein-associated phospholipase A(2) content was quantified by immunoblotting and lysophosphatidylcholine (lysoPC) by liquid chromatography tandem mass spectrometry. Additional biomolecular profiling by immunoblotting included C-reactive protein, p67phox, and matrix metalloproteinase-2 and -9. Macrophage plaque content was determined by quantitative immunostaining, plaque collagen content by quantitative Sirius red staining. Follow-up for cardiac death and non-fatal acute myocardial infarction was accomplished over a period of 48 +/- 14 months. Expression of Lp-PLA(2) and lysoPC was higher in carotid plaques of patients with than without cardiac events [median 1.6 (25th, 75th percentile 0.9, 2.5) vs. 0.8 (0.5, 2.0), P = 0.01 and 413 (281, 443) vs. 226 (96, 351) mmol/L, P = 0.03]. Smoking and point increase in carotid Lp-PLA(2) expression but no other traditional cardiovascular risk factor, histological or molecular marker remained predictive of cardiac events in the multivariate Cox proportional hazard analyses [HR 3.65 (1.36-9.83), P = 0.01 and HR 1.34 (1.01-1.77), P = 0.039]. Carotid plaque Lp-PLA(2) expression above the median constituted a more than three times higher risk for cardiac events [HR 3.39 (1.13-10.17), P = 0.03]. CONCLUSION: Lipoprotein-associated phospholipase A(2) expression in carotid artery plaques is a predictor of long-term cardiac outcome. The current study supports the concept of atherosclerosis as a systemic disease with multi-focal complications and personalized medicine.

Prevention of vasa vasorum neovascularization attenuates early neointima formation in experimental hypercholesterolemia.

Vasa vasorum (VV) neovascularization is a key feature of early atherosclerosis and adds substantial endothelial exchange-surface to the coronary vessel wall. Thus, it is conceivable that VV neovascularization favors the entry of pro-inflammatory and pro-atherosclerotic blood components into the coronary vessel wall. We sought to investigate the effects of Thalidomide (Th), a potent anti-angiogenic drug on vasa vasorum (VV) neovascularization, vessel wall inflammation, and neointima formation in early experimental atherosclerosis. Female domestic swine, 3 months old, were fed normal (N, n = 12) or high-cholesterol diet (HC, n = 12) for 3 months. In each group six pigs were randomized to 200 mg Thalidomide daily for the diet period (N + Th, HC + Th). LADs were scanned with micro-CT (20 microm cubic voxel size) to determine VV spatial density (#/mm2). Fresh-frozen coronary tissue was used for western blotting (VEGF, TNF-alpha, LOX-1, Ikappabetaalpha and Gro-alpha) and electrophoretic mobility shift assay (EMSA, NFkappabeta). Treatment with Thalidomide preserved VV spatial density [2.7 +/- 0.3 (N), 6.4 +/- 0.7 (HC), 3.5 +/- 0.8 (HC + Th); p = ns HC + Th vs. N] and inhibited the expression of VEGF, TNF-alpha and LOX-1, but not NFkappabeta activity in the coronary vessel wall. Immunofluorescence analyses revealed co-localization of vWF but not SMA and NFkappabeta, TNF-alpha as well as VEGF in HC and HC + Th coronaries. Intima-media thickness was significantly inhibited in HC + Th compared to HC. Serum levels of hs-CRP and TNF-alpha did not differ among the groups. Our study supports a role of VV neovascularization in the development of and a therapeutic potential for anti-angiogenic intervention in early atherosclerosis.

The ageing endothelium, cardiovascular risk and disease in man.

Ageing is a major risk factor for cardiovascular disease, not only because there is a process of vascular ageing per se but also because ageing increases the time of exposure to other cardiovascular risk factors. Endothelial dysfunction is now considered an early and important mechanism that predisposes to atherothrombotic damage and thus contributes to the occurrence of cardiovascular events. The normal endothelium exerts a major vascular-protecting role by secreting substances, the most important of which is nitric oxide (NO). In disease conditions (such as the presence of cardiovascular risk factors), activation of endothelial cells can lead to the production and release of contracting factors, which counteract the beneficial effects of NO, and reactive oxygen species (ROS), which cause NO breakdown. Besides the opposite effects on vascular tone, NO and endothelium-derived contracting factors also respectively inhibit and activate several other mechanisms that are involved in the pathogenesis of atherothrombosis. Moreover, endothelial dysfunction is associated with vascular subclinical damage and, importantly, an increasing body of evidence strongly suggests that it might be an independent predictor for the risk of future cardiovascular events. Like the other traditional risk factors, ageing has been demonstrated to be associated with progressive impairment of endothelial function, in both conduit arteries and resistance vessels, mainly because of an increased production of ROS. Therefore, it is conceivable that endothelial dysfunction plays a major role in predisposing to age-related increased cardiovascular risk in the elderly.

Chronic proteasome inhibition contributes to coronary atherosclerosis.

The proteasome is responsible for the degradation of oxidized proteins, and proteasome inhibition has been shown to generate oxidative stress in vitro. Atherosclerosis is thought to be initiated as a consequence of increased endogenous oxidative stress. The current study was designed to assess whether chronic proteasome inhibition is associated with early coronary atherosclerosis. Female pigs, 3 months of age, were randomized to a normal (N) or high-cholesterol (HC) diet (2% cholesterol, 15% lard) without or with twice weekly subcutaneous injections of the proteasome inhibitor (PSI) MLN-273 (0.08 mg/kg, N+PSI and HC+PSI) for a period of 12 weeks (n=5 per group). Coronary vasorelaxation to bradykinin (10(-10.5) to 10(-6.5) mol/L) and sodium nitroprusside (10(-9) to 10(-5) mol/L) was assessed by in vitro organ chamber experiments, intima-media ratio by morphometric analysis of Elastica-van Gieson-stained slides, and intima superoxide production by dihydroethidium fluorescence. Vasorelaxation to 10(-6.5) mol/L bradykinin was reduced in HC compared with N (69+/-7 versus 90+/-2%, P<0.05) and further reduced in N+PSI and HC+PSI (57+/-6 and 48+/-13%, P<0.05 versus N and HC for each). Compared with N (0.03+/-0.01), intima-media ratio was higher in N+PSI (0.09+/-0.04, P<0.01) and HC+PSI (0.15+/-0.06, P<0.05). Compared with N (0.6+/-0.9% of intima area), dihydroethidium fluorescence was higher in HC, N+PSI, and HC+PSI (8.9+/-1.6, 6.0+/-3.5, and 7.2+/-3.9% of intima area, P<0.05 for all). Thus, chronic proteasome inhibition is associated with increased coronary artery oxidative stress and early atherosclerosis. These findings support the significance of the proteasome and related protein quality control for vascular biology and pathology.

Lack of pharmacokinetic bioequivalence between generic and branded amoxicillin formulations. A post-marketing clinical study on healthy volunteers.

AIMS: There are concerns about the quality of generic drugs in the postmarketing setting. The aim was to establish whether two generic formulations of amoxicillin, available on the Italian market, fulfil the criteria for clinical pharmacokinetic bioequivalence vs. the branded drug. METHODS: Two generic amoxicillin products (generic A and B) were selected among four fast-release tablet formulations available on the Italian market. Twenty-four healthy adult volunteers of either sex participated to a single-dose, randomized, three-treatment, crossover, single-blind bioequivalence study designed to compare generic A and B with branded amoxicillin. Plasma samples were collected at preset times for 24 h after dosing, and assayed for amoxicillin levels by high-performance liquid chromatography. RESULTS: Ninety percent confidence intervals of AUC ratios were 0.8238, 1.0502 (ratio 0.9302) and 0.8116, 1.1007 (ratio 0.9452) for generic A and B vs. branded amoxicillin, respectively. Ninety percent confidence intervals of C(max) ratios were 0.7921, 1.0134 (ratio 0.8960) and 0.8246, 1.1199 (ratio 0.9610) for generic A and B vs. branded amoxicillin, respectively. The mean pharmacokinetic profiles showed that the AUC value of branded amoxicillin was 8.5 and 5.4% greater than that estimated for generic A and B, respectively. Few adverse events were recorded; these were not serious and occurred without apparent relationship to any specific amoxicillin formulation. CONCLUSIONS: These results indicate that one of the two marketed amoxicillin generics analysed in the present study is not bioequivalent to the brand leader product for C(max) on the basis of single-dose pharmacokinetic assessment.

Enhanced expression of Lp-PLA2 and lysophosphatidylcholine in symptomatic carotid atherosclerotic plaques.

BACKGROUND AND PURPOSE: Circulating lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) has emerged as a novel biomarker for cardiovascular diseases. However, the correlation between the plaque expression of Lp-PLA(2) and plaque oxidative stress, inflammation, and stability as well as the clinical presentation remains poorly defined, especially for cerebrovascular disease. Therefore, this study was performed to test the hypothesis that Lp-PLA(2) expression is higher in symptomatic than in asymptomatic carotid plaques of patients undergoing carotid endarterectomy. METHODS: The expression of Lp-PLA(2) in 167 carotid artery plaques was determined by immunoblotting and immunostaining. Plaque oxidative stress, inflammation, and stability were quantified by NAD(P)H oxidase p67phox and MMP-2 immunoblotting, oxidized LDL (oxLDL) immunoreactivity, macrophage and Sirius red collagen staining. Lysophosphatidylcholine 16:0 (lysoPC) concentration was measured in 55 plaques using liquid chromatography tandem mass spectrometry. RESULTS: Lp-PLA(2) expression was significantly higher in plaques of symptomatic patients than asymptomatic patients (1.66+/-0.19 versus 1.14+/-0.10, P<0.05) and localized mainly to shoulder and necrotic lipid core areas in colocalization with oxLDL and macrophage content. Similarly, Lp-PLA(2) expression was related to collagen content, which was lower in plaques from symptomatic patients than in plaques from asymptomatic patients (9.1+/-2.2 versus 18.5+/-1.7% of staining/field, P<0.001). LysoPC plaque concentration was significantly higher in plaques of symptomatic than asymptomatic patients (437.0+/-57.91 versus 228.84+/-37.00 mmol/L, P<0.05). CONCLUSIONS: Symptomatic carotid artery plaques are characterized by increased levels of Lp-PLA(2) and its product lysoPC in correlation with markers of tissue oxidative stress, inflammation, and instability. These findings strongly support a role for Lp-PLA2 in the pathophysiology and clinical presentation of cerebrovascular disease.

Anthropometric and dietary determinants of blood pressure in over 7000 Mediterranean women: the European Prospective Investigation into Cancer and Nutrition-Florence cohort.

BACKGROUND: Anthropometric characteristics and dietary habits are widely recognized to influence blood pressure. We evaluated their role in a large series of Mediterranean adult women. METHODS: In Florence, in the European Prospective Investigation into Cancer and Nutrition, we recruited 10 083 women, aged 35-64 years. Detailed information on diet, lifestyle, physical activity, and medical history were collected. Anthropometric indices and systolic and diastolic blood pressures were measured at recruitment using standardized procedures. Overall, after excluding those women who reported a clinical diagnosis of hypertension and/or an antihypertensive treatment and those without measurements, 7601 women were available for analyses with an average systolic and diastolic blood pressure value of 123.2+/-16.0 and 78.7+/-9.4 mmHg, respectively. RESULTS: Multivariate regression models showed that body mass index (P<0.0001) and waist circumference (>or=88 cm, P<0.0001), as well as processed meat, potatoes, and wine consumption, were directly associated with both systolic and diastolic values. In contrast, a high consumption of selected foods resulted inversely associated with systolic (total vegetables, yoghurt, and eggs), diastolic (olive oil) or both systolic and diastolic values (leafy vegetables, milk, coffee). Analyses performed on nutrients showed a positive association with alcohol and sodium intake, and an inverse one with potassium and micronutrients derived from fruits and vegetables. CONCLUSION: In this large series of women from Tuscany, Central Italy, we confirm the independent influence of anthropometric characteristics on blood pressure. The role of specific foods and nutrients in modulating blood pressure also emerged, suggesting a central role for lifestyle modifications in blood pressure control.

Phosphodiesterase 5 inhibition in essential hypertension.

Phosphodiesterase (PDE) 5 inhibitors reduce cyclic guanylate monophosphate breakdown, promoting vascular relaxation in the corpora cavernosa and penile erection during sexual stimulation. Sildenafil, vardenafil, and tadalafil were approved as effective treatments for male erectile dysfunction. Because PDE5 is present in artery and vein smooth muscle cells throughout the body, PDE5 inhibitors have mild systemic vasodilatory effects and thus the potential to impact the vascular system. The US Food and Drug Administration has approved PDE5 inhibitors for treating pulmonary hypertension. Moreover, their systemic vasodilating properties theoretically make these drugs suitable for treating hypertension. Studies indicate that PDE5 inhibition may be an option for reducing blood pressure in hypertensive patients. Additional benefits may be related to improved arterial stiffness and endothelial dysfunction, two early vascular abnormalities characterizing essential hypertension. More investigation is needed on PDE5 inhibitors as antihypertensive drugs, especially with slow-release formulations or compounds with long half-life. Studies on safety during long-term administration, interactions with antihypertensive and nonantihypertensive drugs, and effect on target organ damage are needed.

Omega 3 : where do we stand?

Omega-3 fatty acids are essential polyunsaturated fatty acids that are crucial components of plasma membrane phospholipids. They influence cell structure and function and have anti-thrombotic and anti-arrhythmic properties, thus potentially exerting a favourable action on primary and secondary prevention of cardiovascular events. However, the supposed beneficial effect of omega-3 fatty acids in the management of cardiovascular risk has been evaluated only in a relatively small number of interventional studies, with results that are not consistent and are only suggestive of a putative beneficial effect of omega-3 supplementation on the prevention of cardiovascular mortality. Benefits have been reported mainly for the prevention of sudden death in patients with recent myocardial infarction and for primary and secondary prevention of nonfatal cardiac events in populations with high fish intake. Therefore, only ongoing trials will provide definitive data to elucidate whether omega-3 fatty acids could represent a new therapeutic approach for cardiovascular disease.

Increased spatial vasa vasorum density in the proximal LAD in hypercholesterolemia--implications for vulnerable plaque-development.

OBJECTIVE: Vasa vasorum (VV) neovascularization is associated with advanced and ruptured atherosclerotic lesions that occur predominantly within the proximal third of the LAD. To investigate further the possible role of VV spatial distribution in determining this predominantly proximal location of complex lesions we analyzed the changes in VV spatial densities along the LAD in early atherosclerosis. METHODS AND RESULTS: Three-month-old, female domestic pigs were placed on normal (N; n=6) or high-cholesterol (HC; n=6) diet for 3 months. VV count, vascular-area-fraction (Sigma vasa vasorum areas/mm(2) vessel wall area, i.e., flow capacity), and the endothelial-surface-fraction (Sigma vasa vasorum endothelial surfaces/mm(3) vessel wall volume) were calculated in three equal thirds of the coronary artery from microcomputed-tomography images. In N animals, the proximal thirds tended to have a higher vascular-area-fraction (mean+/-S.D., 1.4+/-0.6 versus 0.9+/-0.3 and 0.9+/-0.2%; P=0.1) and endothelial-surface-fraction (0.72+/-0.29 versus 0.59+/-0.22 and 0.53+/-0.20 mm(2)/mm(3); NS) than the mid and distal thirds with significantly higher VV counts (26+/-12, 15+/-8, 8+/-5, P=0.01). In HC animals, we observed significant VV neovascularization (3.3+/-1.2 n/mm(2) versus 6.8+/-1.9 n/mm(2), P<0.01), with significantly higher VV counts (24+/-3 and 14+/-3 versus 6+/-4; P<0.001) as well as higher vascular-area- (1.4+/-0.2 and 1.4+/-0.2% versus 0.8+/-0.2%; P<0.001) and endothelial-surface-fractions (0.88+/-0.14 and 0.90+/-0.12 mm(2)/mm(3) versus 0.56+/-0.14 mm(2)/mm(3); P=0.001) within the proximal and middle thirds compared to the distal third. CONCLUSIONS: VV neovascularization in early atherosclerosis leads to a proximally accentuated increase in flow-capacity and endothelial-exchange-surface, which may favour the predominant development of vulnerable atherosclerotic plaques in proximal portions of the LAD.

Ramipril dose-dependently increases nitric oxide availability in the radial artery of essential hypertension patients.

DESIGN AND PARTICIPANTS: A double-blind, crossover, randomized study was designed to evaluate the effect of 3-month treatment with a lower versus a higher antihypertensive dosage of ramipril (5 or 10 mg/day) on nitric oxide (NO)-dependent vasodilation in 46 untreated patients with essential hypertension. Radial artery flow-mediated dilation (FMD), before and after the intra-arterial infusion of NG-monomethyl-L-arginine (L-NMMA), to block NO synthase, and the response to sublingual glyceril trinitrate (GTN, 25 microg) were measured at baseline and after the two treatment periods as a change in artery diameter (computerized system from ultrasound scans). Plasma angiotensin II and oxidative stress markers were also assessed. RESULTS: FMD was significantly (P < 0.01) lower in hypertensive patients (4.6 +/- 1.8%) than in normotensive subjects (7.1 +/- 2.6%), whereas the response to GTN was similar. L-NMMA significantly (P < 0.001) inhibited FMD in normotensive but not in hypertensive subjects. Mean 24-h ambulatory blood pressure, plasma angiotensin II and oxidative stress marker levels were similarly reduced at the end of the two treatment periods. Both dosages of ramipril significantly (P < 0.001) increased FMD (5 mg: 5.9 +/- 2.1%; 10 mg: 6.3 +/- 2.4%) without modifying the response to GTN. However, compared with baseline (11 +/- 19%), the inhibiting effect of L-NMMA on FMD (NO-dependent FMD) was significantly (P < 0.01) greater with ramipril 10 mg (49 +/- 12%) than 5 mg per day (38 +/- 15%). The improvement in FMD and NO-dependent FMD was not related to changes in plasma levels of angiotensin II or markers of oxidative stress. CONCLUSION: Treatment with ramipril at a higher dosage induced a greater improvement in NO-dependent vasodilation compared with the lower antihypertensive dosage in hypertensive patients.

Vulnerable plaque: detection and management.

Because most myocardial infarctions result from the rupture of a plaque that did not significantly compromise the coronary lumen before the event, experts widely accept that the morphology, composition, and degree of inflammation of a coronary atherosclerotic plaque is more important than the degree of luminal stenosis. Two depicting examples are the concentric, calcified lesion that shows significant luminal stenosis but is stable because of the stabilizing clasp of calcification. In contrast, a smaller but inflamed thin fibrous cap atheroma with a big lipid/necrotic core may rupture and cause an immediate fatal coronary occlusion.

Dysregulation of the ubiquitin-proteasome system in human carotid atherosclerosis.

OBJECTIVE: The ubiquitin-proteasome system is the principal degradation route of intracellular and oxidized proteins, thus regulating many cellular processes conceivably important for atherosclerosis. The aim of this study was to evaluate the activity of ubiquitin-proteasome system in human carotid artery plaques in relation to oxidative stress and clinical manifestation. METHODS AND RESULTS: In carotid endarterectomy specimens from 83 asymptomatic and 94 symptomatic patients, content of ubiquitin, ubiquitin conjugates, matrix metalloproteases, and NADPH-oxidase-p67 was evaluated by immunoblotting; proteolytic proteasome activity by fluorometric assay; single and double immunostaining for ubiquitin conjugates, 3-nitrotyrosine, apoptosis, smooth muscle alpha-actin, and macrophage CD-68, as well as Sirius Red staining for collagen were performed. Compared with asymptomatic patients, symptomatic patients showed a more unstable plaque phenotype, an increased degree of apoptosis, a significantly higher ubiquitin conjugates content (17.72+/-1.36 versus 10.99+/-1.04; P<0.001), and lower proteasome activity (5.01+/-0.70 versus 9.41+/-1.19 nmol AMC/mg protein/min; P<0.01). Ubiquitin conjugates content was directly correlated to NADPH-p67 and degree of apoptosis. Immunostaining revealed colocalization of ubiquitin conjugates and 3-nitrotyrosine, and accumulation of ubiquitin conjugates in smooth muscle cells and macrophages. CONCLUSIONS: In human carotid plaques increased oxidative stress is associated with inhibition of the proteasome activity and accumulation of ubiquitin conjugates, particularly in symptomatic patients. These results suggest a possible role of the ubiquitin-proteasome system in influencing plaque stability.

Low-grade systemic inflammation causes endothelial dysfunction in patients with Hashimoto's thyroiditis.

OBJECTIVE: The objective of this study was to assess whether low-grade systemic inflammation might contribute to the pathogenesis of endothelial dysfunction in patients with subclinical hypothyroidism (sHT) and autoimmune thyroiditis. BACKGROUND: sHT patients are characterized by peripheral endothelial dysfunction and low-grade inflammation. METHODS: In 53 sHT and 45 healthy subjects, we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine (Ach) (0.15-15 microg/min.dl) with and without local vascular COX inhibition by intrabrachial indomethacin (50 microg/min.dl) or nitric oxide synthase blockade by N-mono methyl arginine (L-NMMA) (100 microg/min.dl) or the antioxidant vitamin C (8 mg/min.dl). The protocol was repeated 2 h after systemic nonselective COX inhibition (100 mg indomethacin) or selective COX-2 blockade (200 mg celecoxib) oral administrations. RESULTS: sHT patients showed higher C-reactive protein and IL-6 values. In controls, vasodilation to Ach was blunted by L-NMMA and unchanged by vitamin C. In contrast, in sHT, the response to Ach, reduced in comparison with controls, was resistant to L-NMMA and normalized by vitamin C. In these patients, systemic but not local indomethacin normalized vasodilation to Ach and the inhibition of L-NMMA on Ach. Similar results were obtained with celecoxib. When retested after indomethacin administration, vitamin C no longer succeeded in improving vasodilation to Ach in sHT patients. Response to sodium nitroprusside was unchanged by indomethacin or celecoxib. CONCLUSIONS: In sHT patients, low-grade chronic inflammation causes endothelial dysfunction and impaired nitric oxide availability by a COX-2-dependent pathway leading to increased production of oxidative stress.

Vascular reactivity in congenital hypogonadal men before and after testosterone replacement therapy.

CONTEXT: The contribution of endogenous testosterone (TS) in the functional integrity of peripheral circulation in men was studied. OBJECTIVE: The objective of this study was to observe vascular reactivity in male congenital hypogonadal patients before and after prolonged exposure to normal TS levels. DESIGN: This was a longitudinal study in which, basically and after 6-month (range, 6-8 months) androgen treatment, we investigated forearm blood flow (strain-gauge plethysmography) changes induced by intraarterial acetylcholine (Ach), alone or in the presence of N(G)-monomethyl-l-arginine infusion, and by sodium nitroprusside. We also evaluated, by Doppler ultrasound, flow-mediated dilation of the brachial artery (BA) in response to reactive hyperemia (RH) and glyceryl trinitrate (GTN). SETTING: The studies were conducted at university referral centers for andrologic and blood pressure diseases. PATIENTS: Eight adult male Caucasian hypogonadal patients and nine healthy matched control subjects were studied. INTERVENTION: Intervention was TS enanthate (250 mg in 1 ml oily solution) by im injection every 3 wk. RESULTS: At baseline, BA diameter and RH, flow-mediated dilation, and GTN responses showed no difference between the two groups. TS therapy increased plasma total TS (P < 0.02) and reduced high-density lipoprotein (P < 0.01) and total cholesterol (P < 0.04). It did not affect vasodilation to sodium nitroprusside (355 +/- 47%), but it further reduced the vascular response to Ach (187 +/- 29%, P < 0.01 vs. baseline) and abolished the inhibition by N(G)-monomethyl-l-arginine on Ach (inhibition, 3.2%). Moreover, TS therapy decreased (P < 0.01) flow-mediated dilation, whereas it did not modify BA diameter and responses to RH and GTN. CONCLUSIONS: Hypogonadal patients show impaired vascular reactivity, including endothelial-dependent vasodilation due to reduced nitric oxide availability. TS administration further impairs nitric oxide availability in these patients.

Tissue kallikrein gene polymorphisms induce no change in endothelium-dependent or independent vasodilation in hypertensive and normotensive subjects.

BACKGROUND: Tissue kallikrein (TK) generates Lys-bradykinin, which is then converted to bradykinin and releases nitric oxide (NO) from endothelial cells via B2 receptors. TK gene inactivation in mice causes severe endothelial dysfunction, which is also a hallmark of human primary hypertension (PH). Healthy carriers of a loss-of-function Arg to His substitution at position 53 (R53H) of the TK gene exhibit paradoxical arterial eutrophic remodeling. We therefore investigated the impact of this and other TK gene single nucleotide polymorphisms (SNPs) on endothelium-dependent vasodilatation (EDV) and endothelium-independent vasodilatation (EIV) in PH patients and normotensive (NT) subjects. METHODS: The TK gene SNPs were genotyped blind to the phenotype by sequencing. We compared EDV and EIV vasodilatation across TK genotypes in 131 uncomplicated PH patients and 51 healthy NT subjects. EDV and EIV were assessed as the forearm blood flow response to a graded infusion of acetylcholine and sodium nitroprusside, respectively. We also evaluated the impact of the SNPs on NO-mediated EDV and on reactive oxygen species (ROS)-induced NO breakdown with the nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine or vitamin C, respectively. RESULTS: Genotypes and allele frequencies were in Hardy-Weinberg equilibrium and similar in PH and NT. EDV was lower in PH patients than in NT subjects. No TK genotype affected either EDV or EIV per se, or via interaction with gender and age. NO inhibition and scavenging of ROS showed no TK genotype effect on EDV. Similar conclusions were obtained with haplotype analysis. CONCLUSIONS: These results do not support the contention that TK gene SNPs have a major impact in determining NO-mediated responses to acetylcholine.

The T-786C and Glu298Asp polymorphisms of the endothelial nitric oxide gene affect the forearm blood flow responses of Caucasian hypertensive patients.

OBJECTIVES: We sought to investigate whether two polymorphisms located in the promoter (T(-786)C) and exon 7 (Glu298Asp) of the endothelial nitric oxide (NO) synthase (eNOS) gene affected agonists-mediated NO release. BACKGROUND: Endothelial dysfunction can be genetically determined. Therefore, we investigated whether two polymorphisms located in the eNOS gene affected agonists-mediated NO release. METHODS: We compared endothelial-dependent and -independent vasodilation of the different eNOS genotypes in a cross-sectional study on 187 subjects, of whom 137 were uncomplicated essential hypertensive patients (PH) (49 +/- 9 years, 151 +/- 11/99 +/- 5 mm Hg) and 50 healthy normotensive subjects (NT) (43 +/- 16 years, 123 +/- 10/78 +/- 7 mm Hg). Endothelial-dependent and -independent vasodilation was assessed as the forearm blood flow response to incrementally increasing doses of acetylcholine (0.15, 0.45, 1.5, 4.5, 15 microg/100 ml/min) and sodium nitroprusside (1, 2, 4 microg/100 ml/min), respectively. Genotyping was performed with melting curve analysis (Lightcycler) of polymerase chain reaction products from acceptor (5' end-labeled with LCRed 640) and donor probes (3' end-labeled with fluorescein) specific for each polymorphism. The genotype distribution of T(-786)C (CC = 21.9%, CT = 48.7%, TT = 29.4%) and Glu298Asp (GG = 39.0%, GT =51.9%, TT = 9.1%) was similar in PH and NT. A repeated measure analysis of variance showed a blunting of endothelium-dependent vasodilation in PH compared with NT (p < 0.001). A significant effect of the T(-786)C (p = 0.002) but not of the Glu298Asp (p = NS) eNOS polymorphism on endothelial-dependent vasodilation was found. However, we also detected a significant interaction between the T(-786)C and Glu298Asp polymorphism (p < 0.001). No effect on either polymorphism on endothelial-independent vasodilation was seen. CONCLUSIONS: The T(-786)C promoter polymorphism and its interaction with exon 7 Glu298Asp affect endothelium-dependent vasodilation in mild-to-moderate PH patients and NT Caucasian subjects.

Impaired endothelium-dependent vasodilatation in subclinical hypothyroidism: beneficial effect of levothyroxine therapy.

Subclinical hypothyroidism (sHT) is associated with enhanced cardiovascular risk. To test the hypothesis that patients with sHT are characterized by endothelial dysfunction and impaired nitric oxide (NO) availability, in 14 patients [serum cholesterol, 218 +/- 41 mg/dl (5.6 +/- 0.9 mM)] and 28 euthyroid subjects, subdivided into groups A and B [serum cholesterol, 170 +/- 19 mg/dl (4.4 +/- 0.5 mM) and 217 +/- 21 mg/dl (5.6 +/- 0.5 mM), respectively], we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine, an endothelium-dependent vasodilator, at baseline and during infusion of N(G)-monomethyl-L-arginine (L-NMMA), a NO synthase inhibitor. Response to sodium nitroprusside and minimal forearm vascular resistances were also evaluated. In sHT patients, vasodilation to acetylcholine was reduced, compared with group B (+358 +/- 29% vs. +503 +/- 19%, P = 0.0003) and group A (663 +/- 65%, P = 0.02 vs. group B and P = 0.0002 vs. sHT). L-NMMA blunted the vasodilation to acetylcholine in groups A and B (49.1 +/- 6.3% and 42.7 +/- 5.5% maximal forearm blood flow reduction, respectively, P < 0.0001 vs. acetylcholine), whereas it was ineffective in sHT patients (12.8 +/- 2.5%). Response to sodium nitroprusside and minimal vascular resistances were similar. In sHT (n = 9) patients, 6 months of euthyroidism by levothyroxine replacement increased acetylcholine-vasodilation and restored L-NMMA inhibition. Patients with sHT are characterized by endothelial dysfunction resulting from a reduction in NO availability, an alteration partially independent of dyslipidemia and reversed by levothyroxine supplementation.

Control of blood pressure in the community: an unsolved problem.

Available data indicate that blood pressure (BP) is reduced below 140-90 mmHg in less than 30% of hypertensive patients. This poor control of BP derives from lack of diagnosis (unawareness of hypertension), lack of treatment of aware hypertensive patients and lack of efficacy of treatment. Systolic BP (SBP) is now considered as the most important parameter for diagnosis and stadiation of hypertension, above all in elderly patients, and the most frequent cause of unsatisfactory control of BP in the population. Lack of SBP control is caused both by physicians' attitude and difficulty in reducing SBP. Physicians are more prone to consider diastolic BP as the most important parameter for diagnosis and stadiation of hypertension, decision to treat and intensification of treatment and therefore SBP is often forgotten and-or misinterpreted in this decision making process. On the other hand, since current antihypertensive drugs are equally effective in lowering SBP and DBP and-or less effective in lowering SBP more than DBP, SBP is often uncontrolled in treated patients with isolated systolic hypertension or prevalent increase in SBP. The possibility of obtaining better control of SBP in the future is linked to better education of physicians, who need to pay greater attention to SBP as a parameter for diagnosing, treating and intensifying treatment, and to the development of new drugs more active in reducing SBP.