Low-Dose Fluvastatin Prevents the Functional Alterations of Endothelium Induced by Short-Term Cholesterol Feeding in Rabbit Carotid Artery

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, commonly known as statins, are the medical treatment of choice for hypercholesterolemia. In addition to lowering serum-cholesterol levels, statins appear to promote pleiotropic effects that are independent of changes in serum cholesterol. In this study, we investigated the effects of low-dose fluvastatin on antioxidant enzyme activities (superoxide dismutase, SOD; catalase), total nitrite/nitrate levels, and vascular reactivity in 2% cholesterol-fed rabbits. This diet did not generate any fatty streak lesions on carotid artery wall. However, SOD activity significantly increased with cholesterol feeding whereas the catalase activities decreased. The levels of nitrite/nitrate, stable products of NO degradation, diminished. Moreover, dietary cholesterol reduced vascular responses to acetylcholine, but contractions to serotonin were augmented. Fluvastatin treatment abrogated the cholesterol-induced increase in SOD, increased the levels of nitric oxide metabolites in tissue, and restored both the impaired vascular responses to acetylcholine and the augmented contractile responses to serotonin without affecting plasma-cholesterol levels. Phenylephrine contractions and nitroglycerine vasodilatations did not change in all groups. This study indicated that fluvastatin treatment performed early enough to improve impaired vascular responses may delay cardiovascular complications associated with several cardiovascular diseases

Hydrogen sulfide:a novel mechanism for the vascular protection by resveratrol under oxidative stress in mouse aorta

Reactive oxygen species (ROS) decreases bioavailability of nitric oxide (NO) and impairs NO-dependent relaxations. Like NO, hydrogen sulfide (H2S) is an antioxidant and vasodilator; however, the effect of ROS on H2S-induced relaxations is unknown. Here we investigated whether ROS altered the effect of H2S on vascular tone in mouse aorta and determined whether resveratrol (RVT) protects it via H2S. Pyrogallol induced ROS formation. It also decreased H2S formation and relaxation induced by l-cysteine and in mouse aorta. Pyrogallol did not alter sodium hydrogensulfide (NaHS)-induced relaxation suggesting that the pyrogallol effect on l-cysteine relaxations was due to endogenous H2S formation. RVT inhibited ROS formation, enhanced l-cysteine-induced relaxations and increased H2S level in aortas exposed to pyrogallol suggesting that RVT protects against "H2S-dysfunctions" by inducing H2S formation. Indeed, H2S synthesis inhibitor AOAA inhibited the protective effects of RVT. RVT had no effect on Ach-induced relaxation that is NO dependent and the stimulatory effect of RVT on H2S-dependent relaxation was also independent of NO. These results demonstrate that oxidative stress impairs endogenous H2S-induced relaxations and RVT offers protection by inducing H2S suggesting that targeting endogenous H2S pathway may prevent vascular dysfunctions associated by oxidative stress

Prevention of Anterior Scar Formation Following Discectomy with a MediShield Adhesion Barrier: Randomized Experimental Trial

WOS: 000321477200004PubMed ID: 23756969AIM: To investigate whether carboxymethylcellulose/polyethylene oxide (CMC/PEO) gel has a protective effect against epidural scar formation anterior to the dura following discectomy. MATERIAL and METHODS: A barrier gel comprised of CMC and PEO (MediShield) was studied as a material to reduce anterior epidural scar formation in a rabbit laminotomy and discectomy model. After laminotomy and disc puncture, the surgical side was either treated with MediShield or used as a surgical control, as determined by random allocation. Two months after surgery, the animals were euthanized, and their lumbar spines were removed in an en bloc excision for pathological evaluation. Scar formation was evaluated as present or absent. RESULTS: The MediShield group contained 12 rabbits, and the control group contained 7 rabbits. Epidural fibrosis was observed in two out of twelve specimens (17%) in the MediShield group and in three of seven (43%) cases in the control group (P=0.305, Fisher's Exact Test). CONCLUSION: Though it was not statistically significant, we observed a difference between the MediShield and control group that favored the MediShield group. The application of the CMC/PEO gel might protect against epidural fibrosis after lumbar discectomy, but its efficacy needs to be investigated in larger experimental trials

Effects of vitamin C treatment on collar-induced intimal thickening

WOS: 000366530900003PubMed ID: 26719672Vitamin C has efficient antioxidant properties and is involved in important physiological processes such as collagen synthesis. As such, vitamin C deficiency leads to serious complications, including vascular diseases. The aim of this study was to investigate the effects of vitamin C treatment on collar-induced intimal thickening. Rabbits were fed a normocholesterolemic diet and a non-occlusive silicon collar was placed around the left carotid artery for 3, 7, and 14 days. The rabbits were treated with or without vitamin C (150 mg/kg/day). Collar-induced intimal thickening became apparent at day 7. The effect of the collar on intimal thickening was more prominent at day 14. Vitamin C treatment significantly inhibited collar-induced intimal thickening at day 14. The placement of the collar around the carotid artery decreased maximum contractile responses against contractile agents (KCl, phenylephrine, 5-hydroxytryptamine). The effect of the collar on contractile responses was enhanced as days elapsed. Decreased contractile responses of collared carotid arteries normalized at day 14 in the vitamin C treatment group. Vitamin C treatment also restored sensitivity to phenylephrine. The collar also significantly decreased acetylcholine-induced relaxations at day 3 and day 7. Acetylcholine-induced relaxations normalized in collared-arteries in the placebo group at day 14. Vitamin C treatment significantly increased acetylcholine-induced relaxations of both normal and collared carotid arteries at day 14. MMP-9 expression increased in collared arteries at day 3 and day 7 but did not change at day 14. MMP-2 expression increased in collared arteries at day 14. However, vitamin C treatment reduced collar-stimulated expression of MMP-2 at day 14. These findings indicate that vitamin C may have potentially beneficial effects on the early stages of atherosclerosis. Furthermore these results, for the first time, may indicate that vitamin C can also normalize decreased contractile response through perivascular collar placement.Scientific Research Foundation of Ege University, Izmir, TurkeyEge UniversityThis research was supported by the Scientific Research Foundation of Ege University, Izmir, Turkey

The role of hydrogen sulfide on the regulation of vascular tonus in mice aorta and relation with taurine

3rd European Conference on the Biology of Hydrogen Sulfide (H2S) -- MAY 03-06, 2015 -- Athens, GREECEWOS: 00035331390012

Hydrogen sulfide is involved in the antioxidant effects of taurine

3rd European Conference on the Biology of Hydrogen Sulfide (H2S) -- MAY 03-06, 2015 -- Athens, GREECEWOS: 00035331390012

Neuroprotective role of delta opioid receptors in hypoxic preconditioning

Background/aim: The purpose of the present study was to explore the neuroprotective role of delta opioid receptors (DOR) in the rat cortex in hypoxic preconditioning. Materials and methods: Rats were randomly divided into 8 groups: control (C), sham (5), hypoxic preconditioning (PC), severe hypoxia (SH), PC + SH, PC + SH + Saline (PS), PC + SH + DPDPE (DPDPE, selective DOR agonise), PC + SH + NT (NT, Naltrindole, selective DOR antagonist). Drugs were administered intracerebroventrically. Twenty four h after the end of 3 consecutive days of PC (10\% O-2 , 2 h/day), the rats were subjected to severe hypoxia (7\% O-2 for 3 h). Bcl-2 and cyt-c were measured by western blot, and caspase-3 was observed immunohistochemically. Results: Bcl-2 expressions in the PC group were higher than in control, SH, and PC + SH groups. Even though there were no significant differences between the groups in terms of cyt-c levels, caspase-3 immunoreactivity of cortical neurons and glial cells in the severe hypoxia and NT groups were higher than in the control, sham, and hypoxic preconditioning groups. DPDPE administration diminished caspase-3 immunoreactivity compared with all of the severe hypoxia groups. Conclusions: These results suggest that cortical cells are resistant to apoptosis via increased expression of Bcl-2 and decreased immunoreactivity of caspase-3 in the cortex, and that DOR is involved in neuroprotection induced by hypoxic preconditioning via the caspase-3 pathway in cortical neurons