Biomedical subjects

Guido Salvetti

Publications and source records attributed to Guido Salvetti.

6 recordsLinked to original sources

PubMed2006

[Obesity and endothelial dysfunction].

The endothelium plays a crucial role in modulating vascular function and structure. In healthy conditions, nitric oxide produced by endothelial cells exerts not only vasodilating properties, but also several other protective actions toward the vessel wall against the development of atherosclerosis and thrombosis. Traditional cardiovascular risk factors are characterized by endothelial dysfunction caused by an enhanced production of oxidative stress leading to destroy nitric oxide, thus reducing its availability. Abdominal obesity is associated with endothelial dysfunction, through direct mechanisms, such as insulin resistance and the association with risk factors (including diabetes mellitus, hypertension and dyslipidemia), and direct, by the production of adipokines and pro-inflammatory cytokines, which in turn induce oxidative stress leading to a reduced nitric oxide availability. A reduced endothelium-dependent relaxation is a predictor of cardiovascular events in high-risk patients and represents a putative clinical parameter to stratify the cardiovascular risk and a useful marker for therapy efficacy. Weight loss and a modification of lifestyle ameliorate endothelial function in obese patients, an effect due not only to a better glycemic profile, but also secondary to reduced plasma levels of inflammatory markers and adipokines. At present, whether an improvement of endothelial dysfunction secondary to weight loss is significantly associated with a better cardiovascular prognosis is still unknown. (G Ital Cardiol 2006; 7 (11): 715-723)

Cytokines↗

PubMed2005

Physical activity, plasma antioxidant capacity, and endothelium-dependent vasodilation in young and older men.

BACKGROUND: Sedentary aging is associated with oxidative stress and endothelial dysfunction. The aim of this study was to evaluate the relationship between long-term physical activity, plasma antioxidant status, and conduit artery endothelial function in young and older healthy men. METHODS: In young (n = 16) and older athletes (n = 16) and in matched healthy sedentary subjects, endothelium-dependent flow-mediated dilation (FMD) and endothelium-independent response to glyceryl trinitrate (GTN), 400 microg, were measured in the brachial artery from high-resolution ultrasonography. Plasma malondialdehyde (MDA) and antioxidant capacity as total oxyradical scavenging capacity (TOSC) were also evaluated. RESULTS: We found that FMD was lower (< or =0.01) in sedentary older subjects (2.3% +/- 1.0%) as compared with older athletes (5.3% +/- 3.2%) and both sedentary (5.4% +/- 2.0%) and athletically trained (6.1% +/- 3.2%) young subjects. Sedentary older subjects showed higher (P < or = .05) MDA levels and lower (P < .0001) plasma antioxidant capacity as compared with the other subgroups, whereas in older athletes MDA levels and antioxidant capacity were similar to those observed in the young subgroups. In the whole group, FMD, but not GTN, was negatively related to age (r = -0.31, P < .05) and directly related (P < or = .01) to VO2max (r = 0.49) and TOSC against peroxyl (r = 0.69) and hydroxyl radicals (r = 0.53). In the multivariate analysis, TOSC against peroxyl radicals resulted as the most significant predictor of FMD (R2 = 0.60; P = .003). CONCLUSIONS: These results suggest that regular physical activity is associated with preserved antioxidant defenses and endothelial function in older individuals.

Adult↗

PubMed2003

Calcium antagonist treatment by lercanidipine prevents hyperpolarization in essential hypertension.

Essential hypertension is associated with impaired endothelium-dependent vasodilation caused by oxidative stress-induced nitric oxide (NO) breakdown and compensatory production of a hyperpolarizing factor. To test whether calcium antagonist treatment can restore NO availability and prevent hyperpolarization through antioxidant properties, in 15 healthy subjects and 15 patients with essential hypertension, we studied forearm blood flow (strain-gauge plethysmography) modifications induced by intrabrachial bradykinin (5, 15, 50 ng/100 mL per minute), an endothelium-dependent vasodilator, in basal conditions, during infusion of NG-monomethyl-l-arginine (L-NMMA, 100 microg/100 mL per minute), an NO-synthase inhibitor, and ouabain (0.72 microg/100 mL per minute), an Na+-K+ ATPase inhibitor to prevent hyperpolarization. These infusions were repeated in the presence of the antioxidant vitamin C (8 mg/100 mL/min). The response to sodium nitroprusside was also evaluated. In controls, vasodilation to bradykinin was inhibited by L-NMMA and remained unchanged by ouabain or vitamin C. In hypertensive patients, vasodilation to bradykinin was blunted and resistant to L-NMMA but sensitive to ouabain. Vitamin C increased the response to bradykinin and restored the inhibiting effect of L-NMMA while preventing the effect of ouabain. In hypertensive patients, infusions were repeated after 3-month treatment with lercanidipine (10 to 20 mg daily). Lercanidipine decreased plasma lipoperoxides, isoprostanes, and malondialdehyde and increased plasma antioxidant capacity. Moreover, lercanidipine increased the vasodilation to bradykinin and restored the inhibiting effect of L-NMMA on bradykinin-induced vasodilation while preventing the effect of ouabain. Finally, vitamin C no longer exerted its facilitating activity. These results indicate that in essential hypertension, lercanidipine increases endothelium-dependent vasodilation by restoring NO availability and preventing hyperpolarization, an effect probably determined by antioxidant activity.

Antioxidants↗

PubMed2003

Effect of oral contraceptives on endothelial function in the peripheral microcirculation of healthy women.

OBJECTIVES: We assessed whether third-generation oral contraceptive (OC) treatment (30 microg ethinylestradiol + 75 microg gestodene daily) could affect the endothelial function of healthy women. METHODS: In 20 young healthy women (HW) and 10 hypercholesterolemic women (CW) we assessed forearm blood flow (strain-gauge plethysmography) changes induced by the intrabrachial infusion of acetylcholine (ACH) (0.15-15 microg/100 ml forearm tissue/min) and sodium nitroprusside (SNP) (1-4 microg/100 ml forearm tissue/min). ACH was repeated during the nitric oxide synthase inhibitor intra-arterial NG-monomethyl-L-arginine (L-NMMA) (100 microg/100 ml forearm tissue/min) or the antioxidant vitamin C (8 mg/100 ml forearm tissue/min). HW repeated the protocol after 6-month OC (n = 10) or placebo (n = 10) treatment. RESULTS: In HW the maximal vasodilation to ACH, similar between placebo and OC subgroups, was significantly reduced in CW (P < 0.01). Vasodilation to ACH was blunted (P < 0.01) by L-NMMA and unaffected by vitamin C, in both OC and placebo groups. In CW the vasodilation to ACH, not modified by L-NMMA, was improved by vitamin C (P < 0.01). OC treatment raised (P < 0.01) plasma total and low-density lipoprotein cholesterol, and values were similar to those shown by CW. Both OC and placebo intake did not change the response to ACH and the modulation induced by L-NMMA or vitamin C. Vasodilation to SNP was similar in all groups. CONCLUSIONS: In HW 6-month treatment with third-generation OC, although associated with an abnormal lipid profile, does not adversely affect endothelium-dependent vasodilation. This neutral effect could be the balance between a deleterious effect of hypercholesterolemia and a protective effect of OC on endothelial function.

Acetylcholine↗

PubMed2002

Endothelial function in hypertension: role of gender.

Endothelium plays an important role in the modulation of vascular tone and structure mainly through the production of nitric oxide (NO), which causes local vasodilation and counteracts processes leading to atherothrombosis. A dysfunctioning endothelium, characterized by reduced NO availability owing to impairment of the L-arginine-NO pathway and, above all, to production of oxygen free radicals, can impair local vasomotion and promote the development of atherosclerosis and of atherothrombotic vascular events. Aging is associated with endothelial dysfunction both in normotensive subjects and in hypertensive patients, and hypertension seems to induce earlier onset of those mechanisms (i.e. impairment of the L-arginine-NO pathway and oxidative stress) that cause age-related endothelial dysfunction. Premenopausal normotensive women are protected against the deleterious effect of aging on endothelial function, and age-related impairment of endothelial function is attenuated in premenopausal hypertensive women. This protective effect on endothelial function seems to be mediated by endogenous estrogen, which preserves NO availability by activating the L-arginine-NO pathway in normotensive women and, again, by activating this pathway but above all by inhibiting oxidative stress in hypertensive women. Thus, the protective effect of endogenous estrogen on endothelial function could be a plausible mechanism contributing to the lower cardiovascular risk of premenopausal women. Finally, whether endogenous androgen can impair endothelial function is still an unsolved issue since data concerning the effect of testosterone on endothelial function are scanty and contradictory.

Animals↗

PubMedDate not supplied

Hyperhomocyst(e)inemia: is this a novel risk factor in hypertension?

Homocysteine is an intermediate sulfur-containing amino acid formed during intracellular metabolism of methionine. Circulating homocyst(e)ine can be increased by genetic deficiency of enzymatic pathways involved in its catabolism as well as by environmental factors including nutritional deficiencies, life style factors, physiological conditions, drugs and some diseases, which mainly induce deficiency of folate, vitamin B12 and vitamin B6. Therefore plasma homocyst(e)ine can be reduced by vitamin therapy with folate and vitamin B12. Although hyperhomocyst(e)inemia exerts a prothrombotic and proatherosclerotic effect, its relevance in the genesis of the atherosclerotic lesions, as well in the first occurrence of cardiovascular events in normotensive and even more so in hypertensive patients is still to be established. However available data indicate that hyperhomocyst(e)inemia could be an independent risk factor for the recurrence of cardiovascular events in patients with coronary artery disease and in elderly high risk patients. Finally, the possibility that a reduction in plasma homocyst(e)ine induced by vitamin therapy can diminish the risk of cardiovascular events is under evaluation in several controlled longitudinal studies focusing mainly on secondary prevention.

Animals↗