Vitamin D Deficiency and Gender Alter Vasoconstrictor and Vasodilator Reactivity in Rat Carotid Artery.

The vitamin-D-sensitivity of the cardiovascular system may show gender differences. The prevalence of vitamin D (VD) deficiency (VDD) is high, and it alters cardiovascular function and increases the risk of stroke. Our aim was to investigate the vascular reactivity and histological changes of isolated carotid artery of female and male rats in response to different VD supplies. A total of 48 male and female Wistar rats were divided into four groups: female VD supplemented, female VDD, male VD supplemented, male VDD. The vascular function of isolated carotid artery segments was examined by wire myography. Both vitamin D deficiency and male gender resulted in increased phenylephrine-induced contraction. Acetylcholine-induced relaxation decreased in male rats independently from VD status. Inhibition of prostanoid signaling by indomethacin reduced contraction in females, but increased relaxation ability in male rats. Functional changes were accompanied by VDD and gender-specific histological alterations. Elastic fiber density was significantly decreased by VDD in female rats, but not in males. Smooth muscle actin and endothelial nitric oxide synthase levels were significantly lowered, but the thromboxane receptor was elevated in VDD males. Decreased nitrative stress was detected in both male groups independently from VD supply. The observed interactions between vitamin D deficiency and sex may play a role in the gender difference of cardiovascular risk.

Preventive but nontherapeutic effect of danshensu on hypoxic pulmonary hypertension.

OBJECTIVES: Danshensu is a traditional Chinese medicine that is used for treatment of cardiovascular diseases. We previously demonstrated its preventive effect against early-stage hypoxic pulmonary hypertension (HPH) in a rat model. To determine whether danshensu treatment might be useful for patients with chronic HPH, we examined its therapeutic effect in rats with prolonged HPH. METHODS: Adult Sprague-Dawley rats received danshensu (80, 160, and 320 mg/kg) during or after hypoxia exposure to assess preventive and therapeutic effects, respectively. Right ventricle systolic pressure (RVSP), right ventricle hypertrophy index (RVHI), and mean left carotid artery pressure (mCAP) were measured in each group. Western blotting was used to assess transforming growth factor (TGF)-ß expression levels in rats and cultured cells exposed to hypoxia. RESULTS: Preventive danshensu treatment significantly reduced the elevation of RVSP and RVHI in rats exposed to hypoxia, whereas therapeutic danshensu treatment did not; mCAP did not change in any treatment group. The increased expression levels of TGF-ß induced by hypoxia were inhibited by preventive danshensu treatment, but not by therapeutic danshensu treatment. CONCLUSIONS: Although danshensu treatment could prevent HPH, it had no obvious therapeutic effect after development of HPH. Therefore, danshensu might be suitable for clinical treatment of early-stage HPH.

Osteopathic manual therapy in heart failure patients: A randomized clinical trial.

BACKGROUND: Heart Failure (HF) patients usually present with increased arterial resistance and reduced blood pressure (BP) leading to an impaired functional capacity. Osteopathic Manual Therapy (OMT) focused on myofascial release techniques (MRT) and in the balancing of diaphragmatic tensions, has been shown to improve blood flow in individuals using the resistive index (RI). However, its effects in HF patients have not been examined. PURPOSE: To evaluate the acute response of selected osteopathic techniques on RI, heart rate (HR), and BP in patients with HF. METHODS: Randomized-controlled clinical trial of HF patients assigned to MRT (six different techniques with three aimed at the pelvis, two at the thorax, and one at the neck for 15 min) or Control group (subjects in supine position for 15 min without intervention). The RI of the femoral, brachial and carotid arteries was measured via doppler ultrasound while HR and BP were measured via sphygmomanometry before and after a single MRT or control intervention. RESULTS: Twenty-two HF patients equally distributed (50% male, mean age 53 years; range 32-69 years) (ejection fraction = 35.6%, VO2peak: 12.9 mL/kg-1 min-1) were evaluated. We found no intra or inter group differences in RI of the carotid (ΔMRT: 0.07% vs Δ Control:11.8%), brachial (ΔMRT:0.17% vs ΔControl: 2.9%), or femoral arteries (ΔMRT:1.65% vs ΔControl: 0.97%) (P > 0.05) and no difference in HR or BP (ΔMRT:0.6% vs ΔControl: 3%), (P > 0.05). CONCLUSION: A single MRT session did not significantly change the RI, HR, or BP of HF patients.

Long-chain polyunsaturated fatty acids in infant formula and cardiovascular markers in childhood.

To investigate whether children who consumed infant formula supplemented with long-chain polyunsaturated fatty acids (LCPUFAs) had a more favourable cardiovascular profile than children who consumed formula without these fatty acids, we used the Wheezing Illnesses Study Leidsche Rijn, a birth cohort that included 2,468 newborns between 2001 and 2014. Data on infant feeding were obtained by questionnaires. At age 5, blood pressure, carotid intima-media thickness (CIMT), and carotid distension were measured. We used multivariable linear regression analysis to compare levels of cardiovascular markers in formula-fed children born before and after the LCPUFA supplementation. To account for secular trends, we compared levels of cardiovascular markers in a control group of breastfed children from the same cohort born before and after the supplementation. Formula-fed children born after the LCPUFA supplementation (n = 48) had no different systolic blood pressure (-2.58 mmHg, 95% confidence interval, CI [-5.5, 0.30]), diastolic blood pressure (-0.13 mmHg, 95% CI [-2.3, 2.1]), or carotid distension (24.8 MPa-1 , 95% CI [-47.1, 96.6]) and had a higher CIMT (18.6 µm, 95% CI [3.7, 33.5]) than formula-fed children born before the supplementation (n = 163). In the control group, children born after the LCPUFA supplementation (n = 98) had no different systolic- or diastolic-blood pressure, or CIMT, and a higher carotid distension than children born before the supplementation (n = 142). In conclusion, children who consumed infant formula supplemented with LCPUFAs did not have a more favourable cardiovascular profile in early childhood than children who consumed formula without LCPUFAs.

Cardioprotective effects of low-level carotid baroreceptor stimulation against myocardial ischemia-reperfusion injury in canine model.

PURPOSE: The modulation of the autonomic nervous system (ANS) has been shown to prevent myocardial ischemia-reperfusion injury (MIRI). Carotid baroreceptor stimulation modulates the ANS by sympathetic withdrawal and vagal activation. The aim of this study was to assess whether low-level carotid baroreceptor stimulation (LL-CBS) attenuated MIRI and test its underlying molecular mechanisms. METHODS: Forty adult healthy mongrel dogs were randomly assigned to three groups as follows: (1) I/R group (n = 15): left anterior descending artery (LAD) was occluded for 1 h and allowed for 1 h reperfusion; (2) LL-CBS group (n = 15): I/R plus LL-CBS; and (3) sham group (n = 10): sham surgery without stimulation. The voltage-reducing blood pressure by 5% was defined as the threshold. LL-CBS was performed at a voltage that is 80% below the threshold. Infarct size was assessed with Evans blue and TTC staining. The inflammatory cytokines, biomarker of oxidative stress and apoptosis, and connexin 43 (Cx43) expression were measured to assess the injury. RESULTS: The number of ventricular tachycardia/ventricular fibrillation (VT/VF) episodes was significantly decreased in the LL-CBS group compared with the I/R group (2.8 ± 0.8 vs. 7.0 ± 2.6, P < 0.05). LL-CBS reduced tumor necrosis factor α, interleukin (IL)-1, IL-6, and malondialdehyde levels but increased superoxide dismutase level compared with the I/R group (P < 0.05). Meanwhile, LL-CBS significantly decreased the percentage of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL)-positive cardiomyocytes (20 ± 8 vs. 47 ± 12, P < 0.05). Western blotting and real-time polymerase chain reaction (RT-PCR) in Cx43 revealed that LL-CBS caused an increase, respectively, compared with the I/R group (0.75 ± 0.3 vs. 0.3 ± 0.2 and 1.0 ± 0.3 vs. 0.4 ± 0.1, respectively, both P < 0.05). CONCLUSIONS: LL-CBS exerted cardioprotective effects during ischemic reperfusion period potentially by inhibiting inflammation, oxidative stress, and apoptosis and modulating the Cx43 expression.

Plasma FGF23 and Calcified Atherosclerotic Plaque in African Americans with Type 2 Diabetes Mellitus.

BACKGROUND: Fibroblast growth factor 23 (FGF23) is a phosphaturic hormone implicated in disorders of serum phosphorus concentration and vitamin D. The role of FGF23 in vascular calcification remains controversial. METHODS: Relationships between FGF23 and coronary artery calcified atherosclerotic plaque (CAC), aortoiliac calcified plaque (CP), carotid artery CP, volumetric bone mineral density (vBMD), albuminuria, and estimated glomerular filtration rate (eGFR) were determined in 545 African Americans with type 2 diabetes (T2D) and preserved kidney function in African American-Diabetes Heart Study participants. Generalized linear models were fitted to test associations between FGF23 and cardiovascular, bone, and renal phenotypes, and change in measurements over time, adjusting for age, gender, African ancestry proportion, body mass index, diabetes duration, hemoglobin A1c, blood pressure, renin-angiotensin-system inhibitors, statins, calcium supplements, serum calcium, and serum phosphate. RESULTS: The sample was 56.7% female with a mean (SD) age of 55.6 (9.6) years, diabetes duration of 10.3 (8.2) years, eGFR 90.9 (22.1) ml/min/1.73 m2, urine albumin:creatinine ratio (UACR) 151 (588) (median 13) mg/g, plasma FGF23 161 (157) RU/ml, and CAC 637 (1,179) mg. In fully adjusted models, FGF23 was negatively associated with eGFR (p < 0.0001) and positively associated with UACR (p < 0.0001) and CAC (p = 0.0006), but not with carotid CP or aortic CP. Baseline FGF23 concentration did not associate with changes in vBMD or CAC after a mean of 5.1 years follow-up. CONCLUSIONS: Plasma FGF23 concentrations were independently associated with subclinical coronary artery disease, albuminuria, and kidney function in the understudied African American population with T2D. Findings support relationships between FGF23 and vascular calcification, but not between FGF23 and bone mineral density, in African Americans lacking advanced nephropathy.

Effect of Shoushen granule on arterial elasticity in patients with carotid atherosclerosis: a clinical randomized controlled trial.

OBJECTIVE: To investigate the effectiveness of Shoushen granule, Chinese herbal preparation, on carotid artery elasticity in patients with carotid atherosclerosis. METHODS: The total of 156 carotid atherosclerosis patients were randomly divided into the intervention group (83 cases, treated with Shoushen granule) and the control group (73 cases, treated with pravastatin). Brachial-ankle pulse wave velocity baPWV) and Ankle-Brachial Pressure Index (ABI) were measured by automated arteriosclerosis detector. The changes of common carotid artery intima-media thickness (IMT) and parameters of the carotid artery elasticity in patients, including stiffness parameter (ß), pressure-strain elastic modulus (Ep), arterial compliance (Ac), augmentation index (AI), and pulse wave velocity (PWV) were detected by Echo-Tracking (ET) technique before and after 24 week treatment. In the meantime, levels of blood lipid, and liver and renal function were measured respectively. RESULTS: After 24 weeks, baPWV, MT and parameters of the carotid artery elasticity (ß, Ep, AI and PWVß) were markedly decreased in intervention group compared with those of before treatment (P < 0.01), but the level of Ac was increased significantly (P < 0.01). And there were no significant differences compared with control group on the same period (P > 0.05). CONCLUSION: In this pilot study, it was demonstrated ET technology and automated arteriosclerosis detector could be used to evaluate carotid artery elasticity effectively, and the action of Shoushen granule on carotid atherosclerosis might be related to the regulation of carotid artery elasticity.

Effect of panax notoginseng saponins injection on the p38MAPK pathway in lung tissue in a rat model of hypoxic pulmonary hypertension.

OBJECTIVE: To investigate the effect of panax notoginseng saponins (PNS) injection on pulmonary artery pressure and the expression of p38MAPK in lung tissue of rats subjected to chronic hypoxia. METHODS: Thirty adult male Sprague Dawley rats were randomly divided into three groups (ten in each group): rats in control group were exposed to normoxic condition and the rats in hypoxia group and PNS group were subjected to 4-week hypoxia, and PNS injection (50 mg · kg(-1) · d(-1)) was administrated intraperitoneally at 30 min in the PNS group daily before the rats were kept in the hypoxic chamber, while rats in the other two groups received equal dose of normal saline instead. After chronic hypoxia, mean pulmonary artery pressure (mPAP) and mean carotid artery pressure (mCAP) were measured. The heart and lung tissues were harvested, and right ventricle (RV) and left ventricle plus ventricular septum (LV+S) were weighed to calculate the ratio of RV/(LV+S). The expression of p38MAPK mRNA was determined by reverse transcription-polymerase chain reaction, the quantity of phosphorylated p38MAPK (p-p38MAPK) in rat lung tissues and pulmonary arterioles was determined by Western blot and immunohistochemistry. RESULTS: Compared with the control group, mPAP and the ratio of RV/(LV+S) in the hypoxia group were increased, the expression of p-p38MAPK in pulmonary arterioles and p38MAPK mRNA in the lung were higher (P<0.05). The changes of these parameters in the hypoxia group were significantly attenuated by PNS treatment (P<0.05). CONCLUSION: PNS injection was shown to prevent hypoxic pulmonary hypertension at least partly by regulating p38MAPK pathway.

[Relationship of stroke and carotid intima-media thickness and traditional Chinese medicine intervention progress: a review].

Stroke is one of the major diseases that threaten human health, early diagnosis and treatment are very important for stroke. Carotid intima-media thickness (CIMT) is measured noninvasively to diagnosis stroke, and it is a independent predictor for stroke because its thickening can timely predict the incidence and development of stroke. As an important predictor of cardiovascular disease, more and more attention is played on CIMT. In this review, we will make a summary on the important role of CIMT in stroke and the mechanisms of carotid intima-media thickening in stroke as well as the potential use of traditional Chinese medicine in treating carotid intima-media thickening.

Vascular function and risk factors in children with epilepsy: associations with sodium valproate and carbamazepine.

AIM: To investigate biochemical cardiovascular risk factors and vascular endothelial function and structure in children with epilepsy on antiepileptic drugs (AEDs), particularly sodium valproate (VPA) and carbamazepine (CBZ). BACKGROUND: Individuals with epilepsy have increased risk factors for vascular disease, particularly lipid abnormalities and elevated total plasma homocyst(e)ine (tHcy). AED induced B-vitamin deficiencies have been suggested to contribute to this risk. Vitamin B supplementation has consequently been recommended for children on AEDs. Early vascular endothelial dysfunction and atherosclerosis are detectable by measuring flow-mediated dilation (FMD) and intima-media thickness (IMT). METHODS: Thirty children with epilepsy on AEDs (13.3±2.3 years, 14 male) and 30 controls (13.9±2.9 years, 14 male) were recruited. Fasting tHcy, folate, pyridoxal-5-phosphate (PLP), vitamin B12, glucose and lipids were measured. Vascular function and structure were assessed using FMD (brachial artery) and IMT (carotid/aortic arteries). RESULTS: No differences were found between children with epilepsy and controls for tHcy, folate, PLP, lipids, FMD, carotid or aortic IMT. Vitamin B12 levels were elevated and glucose reduced in children treated with VPA. Elevated total cholesterol, cholesterol/HDL ratio and triglycerides occurred in children treated with CBZ. Aortic IMT correlated with weight (r=0.75, p<0.001), BMI (r=0.54, p=0.01), and HDL cholesterol (r=-0.58, p=0.006). CONCLUSION: We found no early changes in vascular function or structure in children on valproate or carbamazepine. We were also unable to confirm previous reports of tHcy abnormalities in this group. This may be due to higher B-vitamin intake, which compensates for loss of vitamins induced by this AED therapy. Vitamin supplementation in children with epilepsy on valproate and carbamazepine is not required in populations with adequate dietary intake of B vitamins.

[Effect of Shenlian extracts on blood flow and vessel pathological changes in rabbits carotid atherosclerosis model induced by low shear stress].

Lipid accumulation in the vessel wall and tunica intima vasorum pathological changes are important factors in the development of atherosclerosis, which are closely related with hemodynamics. In this paper, we established a model of local low shear stress in rabbits using carotid artery cannula and a high cholesterol diet for 2 weeks, 4 weeks and 8 weeks. The effects of Shenlian extract on blood flow, vascular pathology formation and lipid metabolism were assessed by electromagnetic blood flow meter and hematoxylin-eosin staining of the proximal end in carotid artery at different times. The results demonstrate that the relationship between blood flow and shear stress for control, atorvastatin, Shenlian extract high-dose, Shenlian extract middle-dose, and Shenlian extract low-dose were linearly related. The blood flow and the shear stress of proximal end in carotid artery of Shenlian extract (1.12, 2.24, 4.48 g x kg(-1)), and atorvastatin (4.7 x 10(-4) g x kg(-1)) were significantly (P < 0.05)increased compared with the control. Plasma total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) ,and high density lipoprotein cholesterol (HDL-C) were markedly decreased with the increasing of dose and time. This study is the first to prove that the inhibition of Shenlian extract on low shear stress (LSS) induces rabbits carotid atherosclerosis with increasing blood flow and decreasing lipids and vessel pathological changes.

Effect of selected manual therapy interventions for mechanical neck pain on vertebral and internal carotid arterial blood flow and cerebral inflow.

BACKGROUND: Manual therapy of the cervical spine has occasionally been associated with serious adverse events involving compromise of the craniocervical arteries. Ultrasound studies have shown certain neck positions can alter craniocervical arterial blood flow velocities; however, findings are conflicting. Knowledge about the effects of neck position on blood flow may assist clinicians in avoiding potentially hazardous practices. OBJECTIVE: The purpose of this study was to examine the effects of selected manual therapeutic interventions on blood flow in the craniocervical arteries and blood supply to the brain using magnetic resonance angiography (MRA). DESIGN: This was an experimental, observational magnetic resonance imaging study. METHOD: Twenty adult participants who were healthy and had a mean age of 33 years were imaged using MRA in the following neck positions: neutral, rotation, rotation/distraction (similar to a Cyriax manipulation), C1-C2 rotation (similar to a Maitland or osteopathic manipulation), and distraction. RESULTS: The participants were imaged using 3T MRA. All participants had normal vascular anatomy. Average inflow to the brain in neutral was 6.98 mL/s and was not significantly changed by any of the test positions. There was no significant difference in flow in any of the 4 arteries in any position from neutral, despite large individual variations. LIMITATIONS: Only individuals who were asymptomatic were investigated, and a short section of the arteries only were imaged. CONCLUSIONS: Blood flow to the brain does not appear to be compromised by positions commonly used in manual therapy. Positions using end-range neck rotation and distraction do not appear to be more hazardous to cerebral circulation than more segmentally localized techniques.

Effect of magnesium supplementation on carotid intima-media thickness and flow-mediated dilatation among hemodialysis patients: a double-blind, randomized, placebo-controlled trial.

OBJECTIVES: The aim of the present study was to determine the efficacy of oral magnesium (Mg) supplementation on endothelial function through evaluation of carotid intima-media thickness (cIMT), brachial artery flow-mediated dilatation (FMD), and C-reactive protein (CRP) among hemodialysis (HD) patients. METHODS: This randomized, controlled, double-blind clinical trial consisted of 54 patients on HD. One group was treated orally with 440 mg of Mg oxide 3 times per week for 6 months (n = 29). The control group (n = 25) was given placebo using the same administration protocol. cIMT, FMD, serum calcium levels, phosphorus, lipid, CRP, and bicarbonate were measured at baseline and at 6 months in both groups. RESULTS: At 6 months, cIMT was significantly decreased in the Mg group (0.84 ± 0.13 mm at baseline and 0.76 ± 0.13 mm at 6 months, p = 0.001). However, in the placebo group, cIMT was significantly increased (0.73 ± 0.13 and 0.79 ± 0.12 mm, respectively, p = 0.003). When hypertension, diabetes mellitus, smoking, hyperlipidemia, and systemic lupus erythematosus were controlled for in the analysis, the effect of Mg remained significant in both groups (p = 0.000). CONCLUSION: Our results indicate that Mg might not improve endothelial function (CRP level and FMD) and that a decreased cIMT as a marker of atherosclerosis may be due to the inhibition of calcification through the regulation parathormone, calcium, and phosphorus.

Renal responses to long-term carotid baroreflex activation therapy in patients with drug-resistant hypertension.

Carotid baroreflex activation has been demonstrated to provide enduring reductions in arterial blood pressure. The aim of this study was to investigate the effect of long-term therapy on renal function. A total of 322 patients were enrolled in the Rheos Pivotal Trial. Group 1 consisted of 236 patients who started baroreflex activation therapy 1 month after device implantation, whereas in the 86 patients from group 2 the device was activated 6 months later. Serum creatinine and urine albumin/creatinine ratio were collected at screening (before device activation), and at months 6 and 12. Multilevel statistical analyses were adjusted for various covariables. Serum creatinine increased from 78 to 84 µmol/L, and glomerular filtration rate decreased from 92 to 87 mL/min per 1.73 m(2) in group 1 at month 6 (P<0.05). These values did not change any further after 12 months of therapy. Patients with highest glomerular filtration rate showed the greatest decrease in glomerular filtration. Group 2 showed the same trends as group 1 even before device activation at month 6. Systolic blood pressure reduction seemed to be significantly related to the change in glomerular filtration rate in both groups. Albumin/creatinine ratio did not change in both groups during follow-up. In conclusion, baroreflex activation therapy in hypertensive patients is associated with an initial mild decrease in glomerular filtration rate, which may be considered as a normal hemodynamic response to the drop in blood pressure. Long-term treatment does not result in further decrease in renal function, indicating baroreflex activation as a safe and effective therapy.

Interventional treatment of hypertension: a new paradigm.

Hypertension is thought to contribute to more than 7 million deaths worldwide each year and contributes to the development of atherosclerotic lesions that lead to myocardial infarction and stroke. While lifestyle modifications (diet, exercise, weight loss) and pharmacotherapy have been proven to be effective in the treatment of hypertension, as many as half of patients have uncontrolled BP and remain at risk for elevated cardiovascular morbidity and mortality. The main physiologic targets for interventional treatment include alteration of blood flow to the kidney, activation of the carotid baroreflex system, and modification of the renal sympathetic nervous system. The results of prior studies and new studies of interventional treatments of resistant hypertension are covered in this review.

Curcumin ameliorates arterial dysfunction and oxidative stress with aging.

We tested the hypothesis that curcumin supplementation would reverse arterial dysfunction and vascular oxidative stress with aging. Young (Y, 4-6 months) and old (O, 26-28 months) male C57BL6/N mice were given normal or curcumin supplemented (0.2%) chow for 4 weeks (n=5-10/group/measure). Large elastic artery stiffness, assessed by aortic pulse wave velocity (aPWV), was greater in O (448±15 vs. 349±15 cm/s) and associated with greater collagen I and advanced glycation end-products and less elastin (all P<0.05). In O, curcumin restored aPWV (386±15 cm/s), collagen I and AGEs (AGEs) to levels not different vs. Y. Ex vivo carotid artery acetylcholine (ACh)-induced endothelial-dependent dilation (EDD, 79±3 vs. 94±2%), nitric oxide (NO) bioavailability and protein expression of endothelial NO synthase (eNOS) were lower in O (all P<0.05). In O, curcumin restored NO-mediated EDD (92±2%) to levels of Y. Acute ex vivo administration of the superoxide dismutase (SOD) mimetic TEMPOL normalized EDD in O control mice (93±3%), but had no effect in Y control or O curcumin treated animals. O had greater arterial nitrotyrosine abundance, superoxide production and NADPH oxidase p67 subunit expression, and lower manganese SOD (all P<0.05), all of which were reversed with curcumin. Curcumin had no effects on Y. Curcumin supplementation ameliorates age-associated large elastic artery stiffening, NO-mediated vascular endothelial dysfunction, oxidative stress and increases in collagen and AGEs in mice. Curcumin may be a novel therapy for treating arterial aging in humans.

Troubleshooting the rabbit ferric chloride-induced arterial model of thrombosis to assess in vivo efficacy of antithrombotic drugs.

INTRODUCTION: The FeCl3-induced arterial model of thrombosis is one of the most widely used animal models to assess arterial efficacy of new antithrombotic drug candidates. This model is well-established in rodents but in a less extent in the rabbit. In this work, we present a methodology for a rabbit FeCl3-induced arterial model of thrombosis derived from our troubleshooting which allows the generation of reliable efficacy data for new antithrombotic drug candidates. METHODS: Rabbits were administered with heparin 4.5U/kg/min, argatroban 10µg/kg/min or saline by intravenous infusion. The blood flow was monitored using a Doppler flow probe. The time from the application of FeCl3 to the recorded zero blood flow was defined as the time to occlusion, with a maximum recording time of 60min post-FeCl3 application. After 30min of infusion, thrombosis was induced by wrapping a FeCl3-saturated filter paper around the carotid artery caudal to the flow probe. Animals were subject to exclusion criteria based on the visual aspect of the artery FeCl3-induced injury and based on changes in blood flow upon FeCl3 application. RESULTS: Following the application of FeCl3, a mean time to occlusion for saline, heparin and argatroban of 24.3±1.8, 52.5±4.8 and 53.5±4.5min was obtained, respectively. Mean time to occlusion for heparin and argatroban administered groups was significantly different when compared to the saline-treated group (p<0.05). These results for the test compounds represent approximately 80% of the maximum possible prolongation. DISCUSSION: The rabbit FeCl3-induced arterial model of thrombosis presented in this paper derived from our troubleshooting is sensitive and reproducible for the generation of accurate and reliable efficacy data in the assessment of new antithrombotic agents in preclinical drug development.

Conduit vessel stiffness in British south Asians of Indian descent relates to 25-hydroxyvitamin D status.

BACKGROUND: South Asians migrating to Northern latitudes are more susceptible to premature cardiovascular disease (CVD) than expected for given levels of blood pressure. Vitamin D deficiency is common in this group and may play an important role mediating vascular wall senescence in response to central pressure effects. METHODS: A cross-sectional association study. South Asian and White European participants were randomly recruited from a population-based diabetes-screening programme. Carotid-femoral pulse wave velocity (cfPWV), biochemistry (25-hydroxyvitamin D, fasting glucose), anthropometrics, resting blood pressure and a physical activity measure (International Physical Activity Questionnaire) were measured under controlled conditions. PARTICIPANTS: One hundred and thirty-two and 125 age-matched South Asians and White Europeans not taking vitamin D supplementation with a risk factor for diabetes but no overt CVD. RESULTS: Age (mean south Asian: 55.7 vs. White European: 56.0 years), mean arterial pressure (MAP) and calculated CVD risk were similar in both groups. Unadjusted (cf)PWV (m/s) was higher (9.32 vs. 8.68 P = 0.001) and 25-hydroxyvitamin D (nmol/l) lower in (21.29 vs. 52.5 P < 0.001) south Asians. 25-Hydroxyvitamin D independently associated with cfPWV in multivariate modelling adjusted for age, MAP, sex, glucose, heart rate, vasoactive medication and south Asian ethnicity (R = 0.73, P = 0.004). 25-Hydroxyvitamin D but not physical activity was negatively correlated with cfPWV independent of south Asian ethnicity. CONCLUSION: Aortic stiffness is increased in British Indo-Asians without vascular disease despite conventional risk profiles, which are comparable to age-matched white Europeans. This effect may be mediated by a greater pressure-dependent increase in stiffness in individuals with vitamin D insufficiency.

Postinfection A77-1726 treatment improves cardiopulmonary function in H1N1 influenza-infected mice.

Acute respiratory disease is associated with significant morbidity and mortality in influenza. Because antiviral drugs are only effective early in infection, new agents are needed to treat nonvaccinated patients presenting with late-stage disease, particularly those who develop acute respiratory distress syndrome. We found previously that the de novo pyrimidine synthesis inhibitor A77-1726 reversed the influenza-induced impairment of alveolar fluid clearance. Patients with acute respiratory distress syndrome and intact alveolar fluid clearance demonstrate lower mortality than those with compromised fluid clearance. We therefore investigated the effects of treatment with nebulized A77-1726 (67.5 mg/kg) on indices of cardiopulmonary function relevant to the diagnosis of acute respiratory distress syndrome. BALB/cAnNCr mice (8-12 wk old) were inoculated intranasally with 10,000 plaque-forming units/mouse influenza A/WSN/33 (H1N1). Pulse oximetry was performed daily. Alveolar fluid clearance, lung water, and lung mechanics were measured at 2 and 6 days after inoculation in live, ventilated mice by BSA instillation, magnetic resonance imaging, and forced-oscillation techniques, respectively. A77-1726 treatment at 1 day after inoculation delayed mortality. Treatment on Days 1 or 5 reduced viral replication on Day 6, and improved alveolar fluid clearance, peripheral oxygenation, and cardiac function. Nebulized A77-1726 also reversed influenza-induced increases in lung water content and volume, improved pulmonary mechanics, reduced bronchoalveolar lavage fluid ATP and neutrophil content, and increased IL-6 concentrations. The ability of A77-1726 to improve cardiopulmonary function in influenza-infected mice and to reduce the severity of ongoing acute respiratory distress syndrome late in infection suggests that pyrimidine synthesis inhibitors are promising therapeutic candidates for the management of severe influenza.

Watermelon extract supplementation reduces ankle blood pressure and carotid augmentation index in obese adults with prehypertension or hypertension.

BACKGROUND: Ankle-brachial index (ABI) and ankle blood pressure (BP) are associated with increased carotid wave reflection (augmentation index, AIx). Oral L-citrulline and L-arginine from synthetic or watermelon sources have reduced brachial BP, aortic BP, and aortic AIx. A directly measured carotid AIx (cAIx) rather than aortic AIx has been proposed as a better measurement of central AIx. We evaluated the effects of watermelon extract on ankle BP and cAIx in individuals with normal ABI and prehypertension or stage 1 hypertension. METHODS: Ankle and brachial systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), cAIx, ABI, and heart rate (HR) were evaluated in the supine position in 14 adults (11 women/3 men, age 58 ± 1 years) with prehypertension or stage 1 hypertension (153 ± 4 mm Hg). Subjects were randomly assigned to 6 weeks of watermelon extract supplementation (L-citrulline/L-arginine, 6 g daily) or placebo followed by a 2-week washout period and then crossover. RESULTS: Ankle and brachial SBP (-11.5 ± 3.8 and -15.1 ± 2.8 mm Hg), DBP (-7.8 ± 2.3 and -7.6 ± 1.8 mm Hg), and MAP (-9.8 ± 2.6 and -7.3 ± 1.8 mm Hg), and cAIx (-8.8 ± 2.6 %) decreased significantly (P < 0.05) after watermelon supplementation compared to placebo. Watermelon supplementation had no significant effect (P > 0.05) on ABI and HR. CONCLUSIONS: This study shows that watermelon extract supplementation reduces ankle BP, brachial BP, and carotid wave reflection in obese middle-aged adults with prehypertension or stage 1 hypertension and normal ABI, which may reflect improved arterial function.