Importance of intracellular angiotensin II in vascular smooth muscle cell apoptosis: inhibition by the angiotensin AT1 receptor antagonist irbesartan.

The intracellular uptake of Angiotensin II has been described, although its physiological role is not yet understood. We aimed to study the role of Angiotensin II internalization in Angiotensin II-induced apoptosis. Vascular smooth muscle cells were cultured from male Wistar-Kyoto rats and treated with Angiotensin II (1 microM, 48 h).

Role of TGF-beta1 in vascular smooth muscle cell apoptosis induced by angiotensin II.

Both Angiotensin II and transforming growth factor beta-1 (TGF-beta1) are important mediators of vascular smooth muscle cell function and have been reported to mediate the balance between proliferation and apoptosis. Some crosstalk between Angiotensin II and TGF-beta1 in end-organ hypertension has been established. However, whether TGF-beta1 is able to mediate Angiotensin II-induced vascular cell damage remains unknown.

Human vascular smooth muscle cells from diabetic patients are resistant to induced apoptosis due to high Bcl-2 expression.

An emerging body of evidence suggests that vascular remodeling in diabetic patients involves a perturbation of the balance between cell proliferation and cell death. Our aim was to study whether arteries and vascular smooth muscle cells (VSMCs) isolated from diabetic patients exhibit resistance to apoptosis induced by several stimuli. Internal mammary arteries (IMAs) were obtained from patients who had undergone coronary artery bypass graft surgery.

A cholesterol-enriched diet induces ultrastructural changes in retinal and macroglial rabbit cells.

The purpose of this study was to ascertain whether the excess of cholesterol in rabbits induces ultrastructural retinal changes similar to those observed in human age-related macular degeneration (AMD). New Zealand rabbits were divided into two groups: Control (GO; n=10), fed standard diet for 8 months; hypercholesterolemic (G1; n=10), fed with 0.5% cholesterol-enriched diet for 8 months.

Kaempferol inhibits apoptosis in vascular smooth muscle induced by a component of oxidized LDL.

Antioxidants such as flavonoids afford protection against oxysterols-induced toxicity. We have investigated the effect of kaempferol and rutin, active components of red wine, in the apoptosis induced by 7beta-hydroxycholesterol in rat vascular smooth muscle cells. 7beta-Hydroxycholesterol induced apoptosis in vascular smooth muscle which include BcL-x(L) degradation, caspase-3 activation and DNA fragmentation.

Compromised arterial function in human type 2 diabetic patients.

Diabetes is associated with a perturbation of signaling pathways in vascular tissue, which causes vasomotor dysfunction such as hypertension and accelerated atherosclerosis. In the present study, the mechanisms of vasomotor dysfunction, Akt (Thr308 and Ser473) phosphorylation and expression of endothelial NO (nitric oxide) synthase, and inducible NO synthase were investigated in human diabetic internal mammary arteries. The phospho-Akt (Thr308) level in arteries from diabetic patients was reduced to about one-half of the level in nondiabetic patients, suggesting impaired insulin signaling in human diabetic vascular tissue.

Relationship between vasodilation capacity and phenolic content of Spanish wines.

We aimed to determine: 1) the concentration of polyphenols in Spanish red wines, 2) the vasodilatory properties of those wines in relation with their polyphenol concentrations and 3) the vasodilation induced by some of these polyphenols in rat aortic rings. In the wines studied the concentration of rutin and kaempferol was high compared with other polyphenols. All wines relaxed precontracted rat aortic rings and this effect was directly related with the concentration of myricetin and kaempferol in the wines.

Pioglitazone induces vascular smooth muscle cell apoptosis through a peroxisome proliferator-activated receptor-gamma, transforming growth factor-beta1, and a Smad2-dependent mechanism.

Thiazolidinediones, such as pioglitazone, seem to exert direct antiatherosclerotic and antirestenotic effects on type 2 diabetes, in part due to an induction of vascular smooth muscle cell (VSMC) apoptosis. We aimed to study the role of transforming growth factor (TGF)-beta in rat aortic VSMC. Pioglitazone at 100 micromol/l increased apoptosis without affecting DNA synthesis, and this effect was reversed by an anti-TGF-beta1 antibody.

Calcium dobesilate attenuates vascular injury and the progression of diabetic retinopathy in streptozotocin-induced diabetic rats.

Background: Diabetic retinopathy (DR) is a highly specific vascular complication of type 1 and type 2 diabetes mellitus. Calcium dobesilate (DOBE) has been tested in the treatment of diabetic retinopathy showing a slowdown of the progression of the disease after long-term oral treatment. The aim of this study was to determine the effects of DOBE on vascular and diabetic retinopathy in streptozotocin (STZ) diabetic rats.

An in vitro study of different extracts and fractions of Allium sativum (garlic): vascular reactivity.

The aim of this study was to investigate the effect of different novel extracts and fractions obtained from Allium sativum (garlic) on in vitro vessel contraction in order to deepen our knowledge of their mechanism of action on vascular reactivity. The contraction induced by noradrenaline (NE, 10(-6) or 10(-5) M) or KCl (80 mM) was relaxed with all the extracts and fractions studied, but this effect was higher with RG 20-100 (raw garlic fraction) and FG 20-100 (frozen garlic fraction). To increase our understanding of the mechanisms of action of RG 200-100 and FG 200-100, we found their inhibitory actions were retained in the absence of endothelium, whereas inhibition of the entry of extracellular calcium and mobilization of intracellular calcium may play an instrumental role.

Effect of somatostatin on rabbit isolated coronary arteries.

Somatostatin analogues are capable of inhibiting vascular smooth muscle and endothelial cell proliferation. However, little is known about the effect of somatostatin on vascular responses in endothelium-denuded coronary arteries in vitro. The aim of this work was to determine whether or not somatostatin prevented the contractile response induced by 5-hydroxytryptamine and acetylcholine in endothelium-denuded rabbit coronary arteries.