Effect of sulfaphenazole on tissue plasminogen activator release in normotensive subjects and hypertensive patients.

BACKGROUND: A nitric oxide-independent response, possibly mediated by hyperpolarization, regulates vascular tone, acting as a compensatory mechanism in the presence of impaired nitric oxide availability. Cytochrome P450 2C9 (CYP 2C9) is a source of endothelium-derived hyperpolarizing factors and modulates tissue-type plasminogen activator (tPA) release from endothelial cells; however, no effect of hyperpolarization on fibrinolysis has been documented in humans. We aimed to assess the effect of sulfaphenazole, a specific CYP 2C9 inhibitor, on tPA release in normotensive subjects and patients with essential hypertension. METHODS AND RESULTS: tPA release was measured in the forearm microcirculation of 56 normotensivesubjects and 57 patients with essential hypertension after bradykinin (0.015 microg x 100 mL(-1) x min(-1)) and acetylcholine (1.5 microg x 100 mL(-1) x min(-1)) infusions, with or without sulfaphenazole (0.03 microg x 100 mL(-1) x min(-1)). Bradykinin and acetylcholine infusions were repeated with N(G)-monomethyl-l-arginine (L-NMMA; 100 microg x 100 mL(-1) x min(-1)) and/or sulfaphenazole. tPA release by bradykinin and acetylcholine was higher in normotensive subjects than in patients with essential hypertension (P<0.01). Sulfaphenazole (P<0.01) blunted bradykinin-induced but not acetylcholine-induced tPA release in both groups. In normotensive subjects, L-NMMA infusion reduced tPA release (P<0.01). When L-NMMA was coinfused with sulfaphenazole, tPA release induced by bradykinin, but not by acetylcholine, was further reduced (P<0.01). In patients with essential hypertension, tPA release by both agonists was unaffected by L-NMMA, but only bradykinin-induced tPA release was blunted by sulfaphenazole, alone or with L-NMMA (P<001). CONCLUSIONS: Sulfaphenazole inhibits bradykinin-induced tPA release, which suggests a modulatory role of CYP 2C9-derived endothelium-derived hyperpolarizing factors in tPA release in humans. In patients with essential hypertension, tPA release depends exclusively on endothelium-derived hyperpolarizing factor, which is an ineffective compensatory mechanism in the presence of impaired nitric oxide availability.

Plasma and urine aldosterone to plasma renin activity ratio in the diagnosis of primary aldosteronism.

OBJECTIVE: To establish the best cut-off value of the aldosterone (ALD)/plasma renin activity (PRA) ratio when screening patients for primary aldosteronism. One hundred and six patients with primary aldosteronism and 100 essential hypertensive patients were investigated in rigorous standardized conditions. METHODS: The ALD/PRA cut-off values were calculated from both the plasma and urine ALD/PRA ratio and analyzed by receiver operating characteristic (ROC) curve. In patients with PRA below 0.2 ng/ml/h [our radioimmunoassay detection limit], values were calculated both with PRA levels set at 0.2 ng/ml/h ('adjusted') and with PRA levels detected ('unadjusted') in the assay. RESULTS: ROC analysis on the ALD/PRA ratio indicated that the best performance was obtained when the plasma ALD (ng/dl)/PRA ratio was used in comparison with that observed in the urine ALD (microg/day)/PRA ratio. In patients with primary aldosteronism, as a whole group, the cut-off value of 69 corresponded to the best compromise value between sensitivity (96%) and specificity (85%), with and without PRA adjustment. In patients with aldosterone-producing adenoma, the cut-off to obtain 100% sensitivity with high specificity (85%) proved to be 69, with and without PRA adjustment. In patients with bilateral adrenal hyperplasia, both with and without PRA adjustment, the best compromise between sensitivity (94%) and specificity (86%) was a cut-off value of 71. CONCLUSION: The best cut-off to identify patients with primary aldosteronism, corresponding to 69, was obtained by using the plasma ALD/PRA ratio. Adjustment of PRA to 0.2 ng/ml/h does not interfere with calculation of the plasma ALD/PRA ratio cut-off.

Peripheral wave reflection and endothelial function in untreated essential hypertensive patients with and without the metabolic syndrome.

OBJECTIVE: Metabolic syndrome is associated with a high risk of cardiovascular disease in hypertension. We evaluated whether metabolic syndrome is associated with early vascular alterations, such as increased peripheral wave reflections and endothelial dysfunction, in untreated essential hypertensive patients. METHODS: Augmentation index and pulse wave velocity were determined with applanation tonometry in 391 untreated hypertensive patients and 166 controls. Endothelium-dependent response was assessed as flow-mediated dilation of the brachial artery. Metabolic syndrome was defined according to the latest National Cholesterol Education Program Adult Treatment panel III. RESULTS: Hypertensive patients showed significantly (P < 0.001) increased augmentation index and central pulse wave velocity, as well as reduced flow-mediated dilation, compared with controls. No further impairment in augmentation index or flow-mediated dilation was observed between patients with or without the metabolic syndrome components and with increasing number of metabolic syndrome. Age and systolic blood pressure, but no other single factor of the metabolic syndrome, resulted as significant predictors of augmentation index and flow-mediated dilation. Female gender was associated with increased augmentation index (P < 0.05) in the presence of the metabolic syndrome. Central pulse wave velocity was selectively impaired by metabolic syndrome in both genders. Finally, reactive hyperemia was reduced in patients with the metabolic syndrome and decreased significantly with the increasing number of metabolic syndrome. CONCLUSIONS: In untreated hypertensive patients, the presence of metabolic syndrome, which selectively impairs central pulse wave velocity, does not account for a further deterioration of peripheral wave reflection and conduit artery endothelial function. Our results suggest that blood pressure, age and gender are important determinants of peripheral vascular structural and functional parameters in these subjects, irrespective of the metabolic syndrome.

Arterial stiffness, intima-media thickness and carotid artery fibrosis in patients with primary aldosteronism.

OBJECTIVES: To evaluate vascular wall structure and conduit artery stiffness in patients with primary aldosteronism. METHODS: This observational study, conducted in a University Hypertension Center, evaluated the carotid wall by 2-D ultrasonography and ultrasonic tissue characterization, and analyzed arterial stiffness by applanation tonometer. Twenty-three consecutive patients with primary aldosteronism, 24 matched patients with essential hypertension and 15 controls were studied. Intima-media thickness and corrected integrated backscatter signal of the carotid arteries were evaluated. Radial and femoral pulse wave velocity and aortic augmentation index were also investigated. RESULTS: Intima-media thickness in patients with essential hypertension (0.69 +/- 0.03 mm) was higher (P < 0.04) than that in controls (0.59 +/- 0.02 mm). This finding was more evident in primary aldosteronism patients (0.84 +/- 0.03 mm), in whom intima-media thickness was greater than that in controls (P < 0.0001) or in patients with essential hypertension (P < 0.01). Similarly, corrected integrated backscatter signal in patients with essential hypertension (-23.6 +/- 0.35 dB) was higher (P < 0.0001) than that in controls (-26.2 +/- 0.44 dB), but it was even more elevated in patients with primary aldosteronism (-22.1 +/- 0.46 dB), who showed greater corrected integrated backscatter signal than was the case in patients with essential hypertension (P < 0.009) or in controls (P < 0.0001). Femoral pulse wave velocity was higher in primary aldosteronism patients (10.8 +/- 0.57 m/s) than in patients with essential hypertension (9.1 +/- 0.34 m/s, P < 0.03) or in controls (7.1 +/- 0.51 m/s, P < 0.0001). Femoral pulse wave velocity was lower in controls than in patients with essential hypertension (P < 0.0001). The same pattern was observed for radial pulse wave velocity. Aortic augmentation index was higher in primary aldosteronism patients (28.2 +/- 2.1%) than in patients with essential hypertension (26.0 +/- 1.8%) or in controls (16.8 +/- 2.0%, P < 0.001). Patients with essential hypertension likewise exhibited higher aortic augmentation index than controls (P < 0.001). CONCLUSION: Aldosterone excess is responsible per se for vascular morphological (wall thickening and carotid artery fibrosis) and functional (central stiffness) damage.

Preclinical cardiac involvement in phaeochromocytoma: a study with integrated backscatter.

OBJECTIVE: It is well known that vascular and cardiac structure may be influenced by circulating neurohormonal factors. Our aim was to study the myocardial wall texture by integrated backscatter (IBS) analysis in patients with phaeochromocytoma (PHEO). DESIGN: Fourteen patients with PHEO, 15 matched high-normal blood pressure (BP) subjects, 15 mild essential hypertensives and 15 normotensive controls underwent two-dimensional conventional ultrasonography and ultrasonic IBS of the myocardial wall. IBS analysis was performed at both interventricular septum and posterior wall levels. IBS values were expressed in decibels and corrected for the IBS values obtained within the pericardium (C-IBS). The systo-diastolic cyclical variations in IBS (CV-IBS), an index of myocardial contractile performance, were also evaluated. RESULTS: Patients with PHEO showed C-IBS values comparable to those of hypertensive patients, and significantly higher than those of high-normal BP subjects and controls at both septum and posterior wall levels (P < 0.001 for all). In PHEO patients, CV-IBS was lower than that of normotensive, high-normal BP subjects and hypertensive patients, at both septum and posterior wall levels (P < 0.001 for all). An inverse relationship was found in the PHEO group between 24-h urinary normetanephrine and CV-IBS of both septum (r(2) = -0.29, P < 0.05) and posterior wall (r(2) = -0.46, P < 0.05). CONCLUSIONS: Our results show that patients with PHEO have myocardial remodelling characterized by increased myocardial fibrosis, confirmed by an increase in the overall myocardial backscatter level measured. The observed decrease in the magnitude of CV-IBS suggests an impairment of myocardial contractile performance. These results may provide insights into the role of catecholamines in left ventricular (LV) structure and function in PHEO.

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.

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.

Left ventricular diastolic dysfunction in elderly hypertensives: results of the APROS-diadys study.

BACKGROUND: A number of patients with chronic heart failure (CHF) have diastolic but not systolic dysfunction. This occurs particularly in the elderly and in hypertension, but the prevalence of diastolic dysfunction in elderly hypertensives without CHF has never been investigated systematically. METHODS AND RESULTS: The Assessment of PRevalence Observational Study of Diastolic Dysfunction (APROS-diadys) project was a cross-sectional observational study on elderly (age >/= 65 years) hypertensives without systolic dysfunction [left ventricular ejection fraction (LVEF) >/= 45%] consecutively attending hospital outpatient clinics in Italy, in order to establish the prevalence of echocardiographic signs of diastolic dysfunction according to various criteria, and to correlate them with a number of demographic and clinical characteristics. Primary criteria for diastolic dysfunction was an E/A ratio (ratio between transmitral peak velocities of E and A waves) < 0.7 or > 1.5 on echocardiographic Doppler examination. Secondary criteria were: E/A < 0.5 and deceleration time (DT) > 280 ms, or isovolumic relaxation time (IVRT) > 105 ms or pulmonary vein (PV) peak systolic/peak diastolic flow (S/D) ratio > 2.5 or PV atrial retrograde flow (PV A) > 35 cm/s. Throughout Italy, 27 447 patients were screened in 107 clinics, with 24 141 excluded according to protocol. Among the remaining 3336 patients, 754 (22.6%) had signs of CHF. After exclusion of 37 protocol violators, 2545 patients (49.0% men, mean age 70.3 years, 95.4% under antihypertensive treatment) were studied ultrasonographically. Diastolic dysfunction (primary criteria) was found in 649 (25.8%) patients. Multiple logistic regression analysis found age, gender, left ventricular mass, systolic and pulse pressures and midwall shortening fraction as significant covariates. Using secondary criteria, the prevalence of diastolic dysfunction was higher (45.6%), mostly because of IVRT > 105 ms or PVA flow > 35 cm/s. CONCLUSION: CHF and diastolic dysfunction are highly prevalent in elderly hypertensives attending hospital clinics.

Supplementation with vitamins C and E improves arterial stiffness and endothelial function in essential hypertensive patients.

BACKGROUND: Essential hypertension is characterized by endothelial dysfunction, arterial stiffness, and increased oxidative stress. We evaluated the effect of short-term combined treatment with the antioxidants vitamins C and E on endothelial function, arterial stiffness, and oxidative stress in untreated essential hypertensive patients. METHODS: A randomized, double-blind, placebo-controlled, crossover study design was used to assign 30 male essential hypertensive patients to either vitamin C (1 g) and vitamin E (400 IU) or placebo for 8 weeks. Endothelium-dependent response was assessed as flow-mediated dilation (FMD) of the brachial artery. Arterial stiffness was assessed as central pulse wave velocity (PWV) and augmentation index (AIx). Plasma markers of oxidative stress and antioxidant status were measured. RESULTS: After vitamin supplementation, FMD was significantly improved. Central PWV was significantly reduced, while AIx tended to decrease. Plasma vitamin levels and antioxidant capacity increased significantly. Levels of oxidative stress decreased. Changes in central PWV were related to changes in levels of oxidative stress. CONCLUSIONS: Combined treatment with vitamins C and E has beneficial effects on endothelium-dependent vasodilation and arterial stiffness in untreated, essential hypertensive patients. This effect is associated with changes in plasma markers of oxidative stress.

Therapeutic implications of recent megatrials: in favor of old drugs.

Data from controlled clinical studies comparing active drugs versus placebo or comparing different classes of drugs and their meta-analysis seem to indicate that although more subtle differences in the effects of various antihypertensive drugs cannot be ruled out, the protective effects against cardiovascular morbidity and mortality of all classes of drugs, including conventional therapy based on diuretics and beta-blockers and their combination, are largely explained by the extent of blood pressure (BP) reduction. Therefore BP control is still the main target of antihypertensive therapy. The benefits of diuretics have been well documented, particularly when these drugs are used at appropriate and/or optimal doses to achieve the optimal antihypertensive effect with the least occurrence of side effects, including negative metabolic effects. Therefore they must still be included among first line antihypertensive drugs. By contrast, beta-blockers seem recently to have lost their previously favored status as initial therapy for hypertension owing to their lower preventive effects against cardiovascular events as compared with diuretics in elderly hypertensive patients and against stroke as compared with other treatments, and to their negative metabolic effects. However, although evidence-based data must be taken into account, the choice of antihypertensive therapy aimed at BP control in individual patients must be made according to clinical characteristics. We believe that a wide range of choices among various antihypertensive drugs, above all diuretics and also beta-blockers, offers an appropriate possibility of selecting the right drug and the right combinations according to the clinical profile of the individual patient.

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.

Recombinant human thyrotropin reduces endothelium-dependent vasodilation in patients monitored for differentiated thyroid carcinoma.

AIM: We evaluated endothelial-dependent vasodilation after administration of recombinant human TSH (rhTSH) in patients monitored for differentiated thyroid carcinoma. The role of inflammation and oxidative stress was also assessed. PROTOCOL: Twenty-four patients (21 women, mean age 40.5 +/- 9.2 yr) received rhTSH (0.9 mg daily) on 2 consecutive days. At baseline and the day after the second rhTSH injection, endothelium-dependent vasodilation as flow-mediated dilation (FMD, induced by 5 min of forearm ischemia) and endothelium-independent vasodilation (glyceril trinitrate 25 microg, sublingual) were evaluated by high-resolution ultrasound in the brachial artery. At each experimental time, blood was drawn for the evaluation of thyroglobulin, TSH, free T(3), free T(4), as well as IL-6, C reactive protein, TNFalpha, lipoperoxides, and ferric reducing antioxidant power levels as markers of inflammation and oxidative stress. RESULTS: At baseline, patients' serum TSH values were below the normal range [0.12 mIU/liter (range 0.01-0.30)] in the face of normal free T(4) and free T(3) levels; FMD (8.9 +/- 3.4 vs. 9.2 +/- 3.1%, respectively) and response to glyceril trinitrate (11.0 +/- 4.3 vs. 10.8 +/- 4.7%, respectively) were similar in patients and controls. All the patients had serum thyroglobulin value less than 1 ng/ml, suggesting the absence of cancer recurrences. Besides the expected elevation of serum TSH, rhTSH induced a significant impairment of FMD (7.4 +/- 3.0 vs. 8.9 +/- 3.4%; P < 0.01) along with a significant elevation of blood IL-6 (P = 0.01), TNFalpha (P < 0.001), and lipoperoxide levels (P = 0.01), as well as a reduction of ferric reducing antioxidant power (P = 0.01). CONCLUSIONS: rhTSH administration acutely impaired endothelium-dependent vasodilation, possibly through the induction of low-grade inflammation and reduced nitric oxide availability by oxidative stress.

Carotid vascular remodeling in patients with pheochromocytoma.

CONTEXT: The influence of catecholamines on vascular remodeling in humans was investigated. OBJECTIVE: The objective was to study the carotid vascular wall in patients with pheochromocytoma (PHEO). DESIGN AND SETTING: An observational study was conducted in a university referral center for blood pressure diseases. PATIENTS: Fourteen patients with PHEO, 15 matched high-normal essential hypertensives, 15 mild essential hypertensives, and 15 controls underwent two-dimensional conventional ultrasonography and ultrasonic tissue characterization of the carotid wall. MAIN OUTCOME MEASURES: Intimal media thickness (IMT), diameter, and corrected ultrasonic integrated backscatter signal (C-IBS) of carotid arteries were evaluated. RESULTS: IMT in PHEOs (0.844 +/- 0.18 mm, mean +/- sd) was greater than not only controls (0.596 +/- 0.09 mm, P < 0.0002) but also high-normal (0.710 +/- 0.17 mm, P < 0.03), and even mild (0.727 +/- 0.20 mm, P = 0.06) hypertensives. IMT in the latter was higher than in controls (P < 0.03), without difference in comparison with high-normal hypertensives. C-IBS values in PHEOs (-21.71 +/- 2.0 dB, mean +/- sd) were greater than in controls (-26.20 +/- 1.73 dB, P < 0.0001) but also than in high-normal (-23.84 +/- 1.16 dB, P < 0.002) and mild (-23.37 +/- 1.99 dB, P < 0.01) hypertensives. C-IBS values in controls were lower than in high-normal (P < 0.0005) and mild (P < 0.0001) hypertensives. Carotid diameter was not significantly different in the four groups. In PHEOs, C-IBS was associated with urinary noradrenaline (r = 0.640, P < 0.01) and normethanephrine (r = 0.737, P < 0.009). CONCLUSIONS: Carotid IMT of PHEOs is higher than in controls and matched groups of hypertensives with comparable or even higher blood pressure. This vascular rearrangement is characterized by increased IBS values due to collagen deposition and vascular fibrosis. Therefore, our data show that abnormal catecholamine levels take part per se in carotid wall remodeling of patients with PHEO.

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.

Endothelium-dependent vasodilation and carotid artery wall remodeling in athletes and sedentary subjects.

In this study, the relationship between age, carotid artery remodeling, and endothelium-dependent vasodilation is investigated in sedentary subjects and athletes. Thirty-two young and old healthy sedentary subjects and 32 age-matched endurance athletes underwent ultrasonography of the carotid wall for measuring intima-media thickness (IMT) and corrected integrated backscatter (C-IBS), two early indicators of the atherosclerosis process. Endothelium-dependent vasodilation was assessed by intra-brachial acetylcholine (strain-gauge plethysmography), at baseline and during NO sythase inhibitor NG-monomethyl-L-arginine (L-NMMA), and the antioxidant Vitamin C. Response to sodium nitroprusside (SNP) was also evaluated. Independently of trained status, IMT and C-IBS were higher in older than in young individuals (p<0.0001), while response to acetylcholine, but not to SNP, was lower (p<0.0001). Older athletes showed lower IMT, lower C-IBS (p<0.0001), greater response to acetylcholine (p<0.0001), and greater inhibition of acetylcholine by L-NMMA (p<0.001) than older controls. Only in older sedentary individuals, Vitamin C increased response to acetylcholine (p<0.001) and restored the inhibiting effect of L-NMMA (p<0.01). In the whole population maximal acetylcholine-induced vasodilation was inversely related to IMT (r=-0.60, p<0.0001) and to C-IBS (r=-0.56, p<0.0001). In conclusion, regular physical training can attenuate the age-related impairment of endothelium-dependent vasodilation, which is related to an attenuation of the age-induced remodeling of the carotid wall.

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.

Cardiac structural and functional changes during long-term antihypertensive treatment with lacidipine and atenolol in the European Lacidipine Study on Atherosclerosis (ELSA).

OBJECTIVES: To evaluate and correlate the effects of long-term antihypertensive treatment on left ventricular (LV) mass and carotid structural changes in a large group of essential hypertensive patients, participating in the European Lacidipine Study on Atherosclerosis (ELSA). DESIGN: In four (Brescia, Glasgow, Naples and Pisa) of 23 centres participating in the ELSA study, an echocardiographic examination was performed at baseline and repeated, until the end of the 4-year study, in essential hypertensive patients, followed-up for carotid quantitative ultrasound examination of intima-media thickness (IMT), after random allocation to treatment with either lacidipine or atenolol (and added hydrochlorothiazide, as required for control of blood pressure). METHODS: M-mode, two-dimensional guided echocardiography was used to measure left ventricular (LV) wall thickness and dimensions, from which LV mass was calculated, using an anatomically validated formula (Penn Convention) and indexed to body surface area (left ventricular mass index, LVMI). The echocardiographic tracings were blindly evaluated in a single reading centre (Brescia). Bilateral IMT was measured at the site of common carotid and bifurcation far walls (CBMmax). RESULTS: At baseline, cardiac and carotid ultrasound scans were available in 278 patients (mean age 54 +/- 7 years, 57% males, 22% obese). A significant correlation was observed between baseline LVMI and CBMmax (r = 0.22, P < 0.001), independent of age. In multivariate analysis, CBMmax and mean 24-h pulse pressure were most strongly associated with baseline LVMI. A significant reduction in LVMI was observed both during lacidipine (n = 96) (-12.5% reduction) and atenolol (n = 78) (-13.9% reduction) treatments (up to 4 years) (P < 0.001 for both, without significant differences between treatments). Changes in LVMI were not related to changes in carotid wall thickness. In multivariate analysis, baseline LV mass and mean 24-h systolic blood pressure changes were significantly associated with changes in LV mass. CONCLUSIONS: In this large, long-term controlled study, antihypertensive treatment with atenolol or lacidipine was accompanied by a similar and significant decrease in LV mass. Treatment-induced changes in LV mass were related to baseline LV mass and changes in 24-h mean systolic blood pressure, without any correlation with changes in carotid structure. In the whole ELSA population, carotid IMT changes have been shown to be unrelated to blood pressure reduction, but significantly influenced by the type of antihypertensive treatment.

Endothelial function and dysfunction. Part I: Methodological issues for assessment in the different vascular beds: a statement by the Working Group on Endothelin and Endothelial Factors of the European Society of Hypertension.

An enormous number of studies in the last two decades have been devoted to investigating the role of the endothelium in cardiovascular diseases. Nonetheless, the optimal methodology for investigating the multifaceted aspects of endothelial dysfunction is still under debate. Biochemical markers, molecular genetic tests and invasive and non-invasive tools with and without pharmacological and physiological stimuli have been introduced. Furthermore newer pharmacological tools have been proposed. However, the application of these methodologies should fulfil a number of requirements in order to provide conclusive answers in this area of research. Thus, the most relevant methodological issues in the research on endothelial function and dysfunction are summarized in this paper.

Endothelial function and dysfunction. Part II: Association with cardiovascular risk factors and diseases. A statement by the Working Group on Endothelins and Endothelial Factors of the European Society of Hypertension.

Dysfunction of the vascular endothelium is a hallmark of most conditions that are associated with atherosclerosis and is therefore held to be an early feature in atherogenesis. However, the mechanisms by which endothelial dysfunction occurs in smoking, dyslipidaemia, hyperhomocysteinaemia, diabetes mellitus, arterial hypertension, cerebrovascular diseases, coronary artery disease and heart failure are complex and heterogeneous. Recent data indicate that endothelial dysfunction is often associated with erectile dysfunction, which can precede and predict cardiovascular disease in men. This paper will provide a concise overview of the mechanisms causing endothelial dysfunction in the different cardiovascular risk factors and disease conditions, and of the impact of the intervention measures and treatments.