The protective effect of cilostazol on isolated rabbit femoral arteries under conditions of ischemia and reperfusion: the role of the nitric oxide pathway

OBJECTIVES: The clinical significance of ischemia/reperfusion of the lower extremities demands further investigation to enable the development of more effective therapeutic alternatives. This study investigated the changes in the vascular reactivity of the rabbit femoral artery and nitric oxide metabolites under partial ischemia/ reperfusion conditions following cilostazol administration. METHODS: Ischemia was induced using infrarenal aortic clamping. The animals were randomly divided into seven groups: Control 90 minutes, Ischemia/Reperfusion 90/60 minutes, Control 120 minutes, Ischemia/Reperfusion 120/90 minutes, Cilostazol, Cilostazol before Ischemia/Reperfusion 120/90 minutes, and Ischemia 120 minutes/Cilostazol/ Reperfusion 90 minutes. Dose-response curves for sodium nitroprusside, acetylcholine, and the calcium ionophore A23187 were obtained in isolated femoral arteries. The levels of nitrites and nitrates in the plasma and skeletal muscle were determined using chemiluminescence. RESULTS: Acetylcholine-and A23187-induced relaxation was reduced in the Ischemia/Reperfusion 120/90 group, and treatment with cilostazol partially prevented this ischemia/reperfusion-induced endothelium impairment. Only cilostazol treatment increased plasma levels of nitrites and nitrates. An elevation in the levels of nitrites and nitrates was observed in muscle tissues in the Ischemia/Reperfusion 120/90, Cilostazol/Ischemia/Reperfusion, and Ischemia/ Cilostazol/Reperfusion groups. CONCLUSION: Hind limb ischemia/reperfusion yielded an impaired endothelium-dependent relaxation of the femoral artery. Furthermore, cilostazol administration prior to ischemia exerted a protective effect on endotheliumdependent vascular reactivity under ischemia/reperfusion conditions

Acesso venoso central de longa duração: experiência com 79 cateteres em 66 pacientes

Procedures such as bone marrow transplantation, chemotherapy, total parenteral nutrition and hemodialysis increasingly require long-term central venous access (LTCVA). According to the indication, fully implantable catheters (with a reservoir) or partially catheters (Broviac- Hickman) are used. In the present study, we evaluated 79 catheres consecutively implanted into 66 patient treated at the University Hospital, Faculty of Medicine of Ribeirão Preto, USP, from January 1993 to June 1997. The following parameters were evaluated: indication of venous access, type of catheter implanted, technique used, early and late complications, and duration of the implant. Thirty four of the 66 patients (51,5%) were men. Mean patient age was 28.2 years. There was a predominance of catheter implantation for chemotherapy in 55 (69.5%) patients and for bone marrow transplantation in 12 (15.2%). Twenty eight catheters with a reservoir (35.5%) and 51 partially implantable catheters (64.5%) were implanted. As to the technique used, 71,4% of the catheters were implanted by percutaneous puncture and the remaining ones by open venous dissection and catheterization. Two types of complications related to the technique occured, 9 infections and 8 late occlusions. The mean duration of catheter was 371 days for the Broviac-Hickman catheters and 395 days for the totally implantable catheters. No death occured due to the implants. The rates of early and late complications observed in the present series are similar to those reported in the literature.Procedimentos, como o transplante de medula óssea, a quimioterapia, a nutrição parenteral total e a hemodiálise, exigem a necessidade cada vez maior do acesso venoso central de longa duração (AVCLD). Utilizam-se, de acordo com a indicação, cateteres totalmente implantáveis (com reservatório) e parcialmente implantáveis (Broviac-Hickman ). Foram avaliados setenta e nove (79) cateteres implantados, consecutivamente, em sessenta e seis (66) pacientes, tratados no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da USP, no período de janeiro de 1993 a junho de 1997. Avaliaram-se os seguintes parâmetros: indicação do acesso venoso, tipo de cateter implantado, técnica utilizada, complicações precoces e tardias e duração do implante. Dos sessenta e seis (66) pacientes, trinta e quatro (34) (51,5%) eram homens. A idade média foi de 28,2 anos. Houve predomínio de indicação de implante de cateter para realizar-se a quimioterapia em cinquenta e cinco (55) (69,5%) pacientes e transplante de medula óssea em doze (12) (15,2%). Foram implantados vinte e oito (28) (35,5%) cateteres com reservatório e cinqüenta e um (51) (64,5%) parcialmente implantáveis. Quanto à técnica utilizada, 71,4% foram implantados por punção percutânea e os demais por dissecção e cateterização venosa, a céu aberto. Ocorreram duas complicações relacionadas à técnica, nove (9) infecções e oito (8) oclusões tardias. A duração média da implantação dos cateteres foi trezentos e setenta e um (371) dias para os cateteres Broviac- Hickman e trezentos e noventa e cinco (395) para o totalmente implantável. Não houve óbito associado aos implantes. Os índices de complicações precoces e tardias, observadas nesta casuística, assemelham- se aos dados encontrados na literatura

Vascular relaxation of canine visceral arteries after ischemia by means of supraceliac aortic cross-clamping followed by reperfusion

<p>Abstract</p> <p>Background</p> <p>The supraceliac aortic cross-clamping can be an option to save patients with hipovolemic shock due to abdominal trauma. However, this maneuver is associated with ischemia/reperfusion (I/R) injury strongly related to oxidative stress and reduction of nitric oxide bioavailability. Moreover, several studies demonstrated impairment in relaxation after I/R, but the time course of I/R necessary to induce vascular dysfunction is still controversial. We investigated whether 60 minutes of ischemia followed by 30 minutes of reperfusion do not change the relaxation of visceral arteries nor the plasma and renal levels of malondialdehyde (MDA) and nitrite plus nitrate (NOx).</p> <p>Methods</p> <p>Male mongrel dogs (n = 27) were randomly allocated in one of the three groups: sham (no clamping, n = 9), ischemia (supraceliac aortic cross-clamping for 60 minutes, n = 9), and I/R (60 minutes of ischemia followed by reperfusion for 30 minutes, n = 9). Relaxation of visceral arteries (celiac trunk, renal and superior mesenteric arteries) was studied in organ chambers. MDA and NOx concentrations were determined using a commercially available kit and an ozone-based chemiluminescence assay, respectively.</p> <p>Results</p> <p>Both acetylcholine and calcium ionophore caused relaxation in endothelium-intact rings and no statistical differences were observed among the three groups. Sodium nitroprusside promoted relaxation in endothelium-denuded rings, and there were no inter-group statistical differences. Both plasma and renal concentrations of MDA and NOx showed no significant difference among the groups.</p> <p>Conclusion</p> <p>Supraceliac aortic cross-clamping for 60 minutes alone and followed by 30 minutes of reperfusion did not impair relaxation of canine visceral arteries nor evoke biochemical alterations in plasma or renal tissue.</p

Pharmacology of the Human Saphenous Vein

Nowadays, the great saphenous vein is the vascular conduit that is most frequently employed in coronary and peripheral revascularization surgery. It is known that saphenous vein bypass grafts have shorter patency than arterial ones, partly because the wall of the normal saphenous vein has different structural and functional characteristics. The features of this vein can be affected by the large distention pressures it is submitted to during its preparation and insertion into the arterial system. Indeed, a vein graft is subjected to considerable changes in hemodynamic forces upon implantation into the arterial circulation, since it is transplanted from a non-pulsatile, low-pressure, low-flow environment with minimal shear stress to a high-pressure system with pulsatile flow, where it undergoes cyclic strain and elevated shear. These changes can be responsible for functional and morphological alterations in the vessel wall, culminating in intima hyperproliferation and atherosclerotic degeneration, which contribute to early graft thrombosis. This review has followed a predetermined strategy for updating information on the human saphenous vein (HSV). Besides presenting the aspects relative to the basic pharmacology, this text also includes surgical aspects concerning HSV harvesting, the possible effects of the major groups of cardiovascular drugs on the HSV, and finally the interference of major cardiovascular diseases in the vascular reactivity of the HSV.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Apoio ao Ensino, Pesquisa e Assistencia do Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto da Universidade de Sao Paulo (FAEPA-FMRP/USP

Influence of high-heeled shoes on venous function in young women

Background: Walking with high-heeled shoes is a common cause of venous complaints such as pain, fatigue, and heavy-feeling legs. The aim of the study was to clarify the influence of high-heeled shoes on the venous return and test the hypothesis that women wearing different styles of high-heeled shoes present an impaired venous return when compared with their values when they are barefoot. Methods: Thirty asymptomatic women (mean age, 26.4 years) wearing appropriately sized shoes were evaluated by air plethysmography (APG), a test that measures changes in air volume on a cuff placed on the calf, while they performed orthostatic flexion and extension foot movements and altered standing up and lying down. The test was repeated in four situations: barefoot (0 cm), medium heels (3.5 cm), stiletto high heels (7 cm), and platform high heels (7 cm). The APG values of venous filling index (VFI), ejection fraction (EF), and residual volume fraction (RVF) were divided into four groups according to heel height and compared by repeated-measures analysis of variance. Results: RVF was increased in the groups wearing high heels (stiletto and platform) compared with the barefoot group (P &lt; .05). RVF was increased in the medium-heel group (3.5 cm) compared with the barefoot group (P &lt; .05), and despite the lack of statistical significance, the medium-heel group showed lower values of RVF compared with the two high-heel groups. The EF parameter followed the opposite tendency, showing higher values for the barefoot group compared with the other three groups (P &lt; .05). Values for VFI were similar in the three situations evaluated. Conclusions: High heels reduce muscle pump function, as demonstrated by reduced EF and increased RVF values. The continuous use of high heels tends to provoke venous hypertension in the lower limbs and may represent a causal factor of venous disease symptoms. (J Vasc Surg 2012;56:1039-44.)Fundacao de Apoio a Pesquisa do Estado de Sao Paulo, Sao Paulo, BrazilFundacao de Apoio a Pesquisa do Estado de Sao Paulo, Sao Paulo, Brazi