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Effects of Cilostazol and Pentoxifylline on Forearm Reactive Hyperemia Response, Lipid Profile, Oxidative Stress, and Inflammatory Markers in Patients With Intermittent Claudication

Peripheral arterial disease may lead to lower limb claudication and increased risk of systemic vascular dysfunction. In this article, the authors have investigated the peripheral vascular dysfunction evaluating forearm blood flow using venous occlusion plethysmography, lipid profile, and C-reactive protein in 60 patients with moderate intermittent claudication treated during 20 weeks with placebo (n = 16), cilostazol (200 mg/d; n = 17), or pentoxifylline (1200 mg/d; n = 15) in a randomized double-blinded clinical trial, taking into account smoking. Forearm blood flow after reactive hyperemia response (FBFh ) or oral nitroglycerine spray to evaluate endothelial-dependent and endothelial-independent vasodilation, respectively, pain-free and maximal walking distance, levels of C-reactive protein, triglycerides, cholesterol, low-density lipoprotein, and high-density lipoprotein—cholesterol in plasma were determined. The results showed that there was an improvement in the high-density lipoprotein—cholesterol, pain-free and maximal walking distance, and FBFh independent of treatment in nonsmoking patients. Cilostazol increased high-density lipoprotein—cholesterol level, maximal walking distance, and FBFh, whereas pentoxifylline reduced C-reactive protein level and increased maximal walking distance in total and nonsmoking groups. No treatment was effective in smokers

Use of microcirculatory parameters to evaluate clinical treatments of chronic venous disorder (CVD).

OBJECTIVES To evaluate changes on cutaneous microangiopathy in chronic venous disorder (CVD) after use of Cirkan [venotonic drug containing Ruscus aculeatus (plant extract), hesperidine methylchalcone (flavonoid) and vitamin C], elastic compression stockings (ECS) or no treatment for four weeks. PATIENTS AND METHODS Fifty-five female patients (85 legs), 25 to 57 years, with at least one limb classified as C2,s or C2,3,s (CEAP classification), were allocated consecutively, according to entrance order, in these three groups. Ten healthy women age-matched were also investigated. Using orthogonal polarization spectral technique (noninvasive method), measurements of functional capillary density (FCD, number of capillaries with flowing red blood cells/mm(2)), capillary morphology (CM, % of abnormal capillaries/mm(2)) and diameters (mum) of dermal papilla (DDP), capillary bulk (DCB) and capillary limb (CD) were obtained on the medial perimalleolar region and later analyzed using CapImage software. RESULTS AND CONCLUSIONS CVD patients showed significant changes on CD and CM compared to healthy subjects in agreement with our previous findings (J Vasc Surg 43:1037-1044, 2006). On Cirkan-treated patients, after 4 weeks, CD decreased on both limbs and CM improved on the left one, suggesting an amelioration of the chronic venous hypertension. No significant changes could be detected on other patient groups. These results confirm the existence of microcirculatory dysfunction in early stages of CVD, probably due to post-capillary hypertension, and further support the venotonic action of Cirkan.

Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach

BackgroundWe aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements.MethodsData from 189 female subjects (34.0±15.5 years, 30.5±7.1 kg/m2), who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA). PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI), waist circumference, systolic and diastolic blood pressure (BP), fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides (TG), insulin, C-reactive protein (CRP), and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV) at rest and peak after 1 min of arterial occlusion (RBCVmax), and the time taken to reach RBCVmax (TRBCVmax).ResultsA total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCVmax varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCVmax, but in the opposite way. Principal component 3 was associated only with microvascular variables in the same way (functional capillary density, RBCV and RBCVmax). Fasting plasma glucose appeared to be related to principal component 4 and did not show any association with microvascular reactivity.ConclusionsIn non-diabetic female subjects, a multivariate scenario of associations between classic clinical variables strictly related to obesity and metabolic syndrome suggests a significant relationship between these diseases and microvascular reactivity.

Beneficial effects of the micronized purified flavonoid fraction (MPFF, Daflon® 500 mg) on microvascular damage elicited by sclerotherapy

Objectives To evaluate if the micronized purified flavonoid fraction (MPFF) treatment could reduce the side effects of sclerotherapy (a procedure frequently used to treat venous disease manifestations) by minimizing the inflammatory response within the surrounding tissues. Method Twenty-two male New Zealand rabbits were treated by gavage with micronized purified flavonoid fraction (MPFF; 300 mg/kg/day) or vehicle (10% lactose solution) during 21 consecutive days, starting 7 days before sclerotherapy. The sclerotherapy consisted of an injection containing 5% ethanolamine oleate solution in the rabbit’s dorsal ear vein. Before and after sclerotherapy, venular and arteriolar diameters, microvascular permeability, functional capillary density (FCD), number of rolling and sticking leukocytes were evaluated on ear microcirculation. Images of the sclerotherapy site were taken before and after the procedure. Results Compared to placebo, MPFF treatment prevented the increase in venular diameter, preserved FCD (P < 0.001) and reduced the number of leaky sites (P < 0.001) and sticking leukocytes (P < 0.001). Imaging confirmed these effects on thrombosis and perivascular edema of the sclerosed vein, 14 days after procedure. Conclusion MPFF treatment limited the postsclerotherapy inflammation in surrounding microvascular network, suggesting that MPFF may prevent undesirable secondary effects of the procedure in this animal model. This study warrants further investigation for its use in clinical conditions.

Gender differences in microcirculation: observation using the hamster cheek pouch.

OBJECTIVES: Estrogen has been shown to play an important protective role in non-reproductive systems, such as the cardiovascular system. Our aim was to observe gender differences in vivo with regard to the increase in macromolecular permeability and leukocyte-endothelium interaction induced by ischemia/reperfusion as well as in microvascular reactivity to vasoactive substances using the hamster cheek pouch preparation. METHODS: Thirty-six male and 36 female hamsters, 21 weeks old, were selected for this study, and their cheek pouches were prepared for intravital microscopy. An increase in the macromolecular permeability of post-capillary venules was quantified as a leakage of intravenously injected fluorescein-labeled dextran, and the leukocyte-endothelium interaction was measured as the number of fluorescent rolling leukocytes or leukocytes adherent to the venular wall, labeled with rhodamin G, during reperfusion after 30 min of local ischemia. For microvascular reactivity, the mean internal diameter of arterioles was evaluated after the topical application of different concentrations of two vasoconstrictors, phenylephrine (α1-agonist) and endothelin-1, and two vasodilators, acetylcholine (endothelial-dependent) and sodium nitroprusside (endothelial-independent). RESULTS: The increase in macromolecular permeability induced by ischemia/reperfusion was significantly lower in females compared with males [19 (17–22) leaks/cm2 vs. 124 (123–128) leaks/cm2, respectively, p<0.001), but the number of rolling or adherent leukocytes was not different between the groups. Phenylephrine-induced arteriolar constriction was significantly lower in females compared with males [77 (73–102)% vs. 64 (55–69)%, p<0.04], but there were no detectable differences in endothelin-1-dependent vasoreactivity. Additionally, arteriolar vasodilatation elicited by acetylcholine or sodium nitroprusside did not differ between the groups. CONCLUSION: The female gender could have a direct protective role in microvascular reactivity and the increase in macromolecular permeability induced by ischemia/reperfusion.

Mast cell coupling to the kallikrein-kinin system fuels intracardiac parasitism and worsens heart pathology in experimental chagas disease

During the course of Chagas disease, infectious forms of Trypanosoma cruzi are occasionally liberated from parasitized heart cells. Studies performed with tissue culture trypomastigotes (TCTs, Dm28c strain) demonstrated that these parasites evoke neutrophil/CXCR2-dependent microvascular leakage by activating innate sentinel cells via toll-like receptor 2 (TLR2). Upon plasma extravasation, proteolytically derived kinins and C5a stimulate immunoprotective Th1 responses via cross-talk between bradykinin B2 receptors (B2Rs) and C5aR. Awareness that TCTs invade cardiovascular cells in vitro via interdependent activation of B2R and endothelin receptors [endothelin A receptor (ETAR)/endothelin B receptor (ETBR)] led us to hypothesize that T. cruzi might reciprocally benefit from the formation of infection-associated edema via activation of kallikrein–kinin system (KKS). Using intravital microscopy, here we first examined the functional interplay between mast cells (MCs) and the KKS by topically exposing the hamster cheek pouch (HCP) tissues to dextran sulfate (DXS), a potent “contact” activator of the KKS. Surprisingly, although DXS was inert for at least 30 min, a subtle MC-driven leakage resulted in factor XII (FXII)-dependent activation of the KKS, which then amplified inflammation via generation of bradykinin (BK). Guided by this mechanistic insight, we next exposed TCTs to “leaky” HCP—forged by low dose histamine application—and found that the proinflammatory phenotype of TCTs was boosted by BK generated via the MC/KKS pathway. Measurements of footpad edema in MC-deficient mice linked TCT-evoked inflammation to MC degranulation (upstream) and FXII-mediated generation of BK (downstream). We then inoculated TCTs intracardiacally in mice and found a striking decrease of parasite DNA (quantitative polymerase chain reaction; 3 d.p.i.) in the heart of MC-deficient mutant mice. Moreover, the intracardiac parasite load was significantly reduced in WT mice pretreated with (i) cromoglycate (MC stabilizer) (ii) infestin-4, a specific inhibitor of FXIIa (iii) HOE-140 (specific antagonist of B2R), and (iv) bosentan, a non-selective antagonist of ETAR/ETBR. Notably, histopathology of heart tissues from mice pretreated with these G protein-coupled receptors blockers revealed that myocarditis and heart fibrosis (30 d.p.i.) was markedly and redundantly attenuated. Collectively, our study suggests that inflammatory edema propagated via activation of the MC/KKS pathway fuels intracardiac parasitism by generating infection-stimulatory peptides (BK and endothelins) in the edematous heart tissues.

Variations in leopard cat (Prionailurus bengalensis) skull morphology and body size: sexual and geographic influences

The leopard cat, Prionailurus bengalensis (Kerr, 1792), is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges) were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads, the longer hind foot of male leopard cats is the main feature of sexual dimorphism among P. b. bengalensis (and probably among P. b. horsfieldii too). External body measurements also indicated the absence of sexual dimorphism among individuals of P. b. borneoensis. Inter-subspecific skull comparisons provided a morphometric basis for differentiating some subspecies. Prionailurus b. horsfieldii and P. b. bengalensis were distinguished only by a subtle difference in PM4 size, indicating that overall skull morphology does not appear to support their separate taxonomical status, in spite of the marked differences reported in their coat patterns. Geological events affecting the Sunda Shelf connection between the Sunda Islands and the mainland during the Last Glacial Maximum seem to have influenced directly the morphological pattern shown by leopard cat subspecies nowadays.

Sex- and age-related morphofunctional differences in skulls of Tayassu pecari and Pecari tajacu (Artiodactyla: Tayassuidae)

Tayassuids exhibit little sexual dimorphism. Sex-related craniomandibular variation was tested in 2 tayassuid species with regard to morphology and function. We analyzed skull features from 61 adult and 37 subadult white-lipped peccaries (Tayassu pecari) and 49 adult collared peccaries (Pecari tajacu) of both sexes. Seventeen skull measurements were used for the morphological characterization, and from these, indexes were obtained for the functional analysis of bite performance (temporal and masseter muscular systems) and head elevation (semispinalis capitis/complexus muscular system). Skull sexual dimorphism of the 2 species and 2 age groups were evaluated independently through discriminant function analysis (DFA), principal component analysis (PCA), and univariate methods. The DFA characterized a slight secondary sexual dimorphism in adult T. pecari and P. tajacu skulls and provided sex classification functions. However, no sexual variation was detected in skull function of adults in either species. Nevertheless, subadult males and females of T. pecari displayed marked morphological and functional skull variation. Subadult females displayed greater skull robustness, and their force indexes indicate an enhancement on bite strength and in head elevation. This could suggest ecomorphological dissimilarities between subadult male and female T. pecari. The sexual precocity of the females reported in the literature could be the main determinant of the marked morphofunctional variation among the T. pecari subadults. These sexual differences in skull morphology seem to become reduced as males mature.

Effects of venotonic drugs on the microcirculation: Comparison between Ruscus extract and micronized diosmine1

BACKGROUND Chronic venous disease of the lower limbs is a common public health problem worldwide with negative impact on quality of life and results with drugs used to treat it are sparse, probably due to lack of good experimental models. OBJECTIVE In this investigation we have tested the effects of two commonly used venotonic substances, Ruscus extract and micronized diosmine, on the microcirculation in vivo. METHODS These substances were given orally, by gavage, during two weeks, twice daily and observations were made using the hamster cheek pouch preparation. RESULTS The drugs elicited a dose-dependent inhibition of (1) macromolecular permeability increase induced by histamine or ischemia followed by reperfusion, being the Ruscus extract more active on both and (2) leukocyte-endothelium interaction, again being the Ruscus extract more effective in the inhibition of the number of adherent and rolling leukocytes. About the duration of the effect after the end of the treatment, both drugs had similar effects but Ruscus extract showed greater permanence of its effect on all observed parameters. CONCLUSIONS Our results suggest that both drugs have antioxidant and anti-inflammatory properties being Ruscus extract more active. It should be added that only Ruscus extract showed a significant venular constriction.

Effects of açaí and cilostazol on skin microcirculation and viability of TRAM flaps in hamsters

BACKGROUND Tissue necrosis caused by insufficient perfusion is a major complication in flap transfer. This study evaluated whether treatment with cilostazol or hydroalcoholic extract of seeds of Euterpe oleracea Mart. (açaí) protects the transverse rectus abdominis myocutaneous (TRAM) flap against ischemic damage in hamsters. MATERIALS AND METHODS Fifty-four hamsters were divided into three oral treatment groups: placebo, açaí, or cilostazol. Caudally based, unipedicled TRAM flaps were raised, sutured back, classified into four vascular zones (I-IV), and evaluated for tissue viability, capillary blood flow (CBF), perfused vessel density (PVD), and microvascular flow index (MFI) by orthogonal polarization spectral imaging at three time points: immediately postoperatively (IPO), 24 h postoperatively (24hPO), and 7 d postoperatively (7POD). RESULTS Comparing to placebo, açaí increased PVD at IPO and açaí and cilostazol increased CBF and PVD at 24hPO in zone I; cilostazol increased CBF, PVD, and MFI at IPO, and CBF at 24hPO in zone II; açaí and cilostazol increased CBF at all time points and PVD and MFI at IPO and 24hPO in zone III; cilostazol increased CBF at IPO and 7POD, açaí increased CBF at 7POD, and both increased PVD and MFI at all time points in zone IV; and açaí and cilostazol increased the percentage of viable area in zones III and IV. CONCLUSIONS Açaí and cilostazol treatments had a protective effect against ischemic damage to TRAM flaps in hamsters, improving microvascular blood flow and increasing the survival of flap zones contralateral to the vascular pedicle (zones III and IV).