Rat Femoral Artery Research Articles

HMGB1/RAGE pro-inflammatory axis promotes vascular endothelial cell apoptosis in limb ischemia/reperfusion injury

ObjectiveHigh-Mobility Group Box 1 (HMGB1) promotes vascular injuries induced by limb Ischemia and Reperfusion (IR), but the molecular mechanisms are not well understood. This study aimed to investigate the role of Receptor for Advanced-Glycation End products (RAGE) in HMGB1-regulated inflammatory response and vascular injury in limb IR using the rat IR and cellular Hypoxia and Reoxygenation (HR) models. MethodsWe analyzed the vascular structure and elastic fiber deposition in rat femoral arteries by histological staining. We determined gene expression in vascular tissues and cells by quantitative RT-PCR, Western blotting and immunofluorescence; analyzed the protein levels in rat serum or cell supernatant by ELISA; and assessed protein interaction by co-immunoprecipitation. We used CCK-8 for analyzing cell viability, and assessed apoptosis by Hoechst staining and flow cytometry. ResultsRAGE inhibition by FPS-ZM1 significantly repressed rat vascular injury that was induced by limb IR treatment. HMGB1 and RAGE expression, P38, ERK1/2, P65 and IKBa phosphorylation, as well as HIF-1a, NLRP3, Caspase-1, TNF-a and IL-6 expression and P65 in nucleus, increased in femoral arteries of a rat IR model and HUVEC undergoing HR treatment, whereas all the factors except HMGB1 and RAGE were inhibited by FPS-ZM1 treatment. In addition, we found that HMGB1 binds with RAGE in HUVEC undergoing HR treatment, which was suppressed by FPS-ZM1. Finally, the apoptosis of HUVEC also increased by HR treatment, but repressed under FPS-ZM1 treatment. ConclusionHMGB1 binds with RAGE to promote vascular inflammation and endothelial cell apoptosis, which mediates vascular injury during acute limb IR.

Development of In Vitro Bioengineered Vascular Grafts for Microsurgery and Vascular Surgery Applications.

Introduction:The use of vascular grafts is continuing to rise due to the increasing prevalence of coronary artery bypass grafting and microvascular flap-based tissue reconstructions. The current options of using native vessels (saphenous vein) or the synthetic grafts (Dacron) have been unable to manage current needs. In this study, we employed an original tissue engineering approach to develop a multi-layered vascular graft that has the potential to address some of the limitations of the existing grafts.Materials and Methods:Biomaterials, gelatin and fibrin, were used to develop a two-layered vascular graft. The graft was seeded with endothelial cells and imaged using confocal microscopy. The graft’s architecture and its mechanical properties were also characterized using histology, Scanning Electron Microscopy and rheological studies.Results:Our methodology resulted in the development of a vascular graft with precise spatial localization of the two layers. The endothelial cells fully covered the lumen of the developed vascular graft, thus providing a non-thrombogenic surface. The elastic modulus of the biomaterials employed in this graft was found to be 5.186 KPa, paralleling that of internal mammary artery. The burst pressure of this graft was also measured and was found close to that of the saphenous vein (~2000 mm Hg).Conclusions:We were successfully able to employ a unique method to synthesize a multi-layered vascularized graft having adequate biological and mechanical properties. Studies are ongoing involving implantation of this developed vascular graft in the rat femoral artery and characterization of parameters such as vascular remodeling and patency.

Novel rodent model for simulation of sylvian fissure dissection and cerebrovascular bypass under subarachnoid hemorrhage conditions: technical note and timing study.

OBJECTIVESylvian fissure dissection following subarachnoid hemorrhage (SAH) is a challenging but fundamental skill in microneurosurgery, and one that has become increasingly difficult to develop during residency, given the overarching management trends. The authors describe a novel rodent model for simulation of sylvian fissure dissection and cerebrovascular bypass under SAH conditions.METHODSA standardized microvascular anastomosis model comprising rat femoral arteries and veins was used for the experimental framework. In the experimental protocol, following exposure and skeletonization of the vessels, extensive, superficial (1- to 2-mm) soft-tissue debridement was conducted and followed by wound closure and delayed reexploration at intervals of 7, 14, and 28 days. Two residents dissected 1 rat each per time point (n = 6 rats), completing vessel skeletonization followed by end-to-end artery/vein anastomoses. Videos were reviewed postprocedure to assess scar score and relative difficulty of dissection by blinded raters using 4-point Likert scales.RESULTSAt all time points, vessels were markedly invested in friable scar, and exposure was subjectively assessed as a reasonable surrogate for sylvian fissure dissection under SAH conditions. Scar score and relative difficulty of dissection both indicated 14 days as the most challenging time point.CONCLUSIONSThe authors' experimental model of femoral vessel skeletonization, circumferential superficial soft-tissue injury, and delayed reexploration provides a novel approximation of sylvian fissure dissection and cerebrovascular bypass under SAH conditions. The optimal reexploration interval appears to be 7-14 days. To the authors' knowledge, this is the first model of SAH simulation for microsurgical training, particularly in a live animal system.

The Efficacy of Systemic Doxycycline Administration as an Inhibitor of Intimal Hyperplasia after Balloon Angioplasty Arterial Injury

Intimal hyperplasia (IH) is the most common indicator for secondary intervention in peripheral vascular disease. Matrix metalloproteinases (MMPs) play a role in IH development due to their degradation of the extracellular matrix. Doxycycline (Doxy), a member of the tetracycline family of antibiotics, is a potent MMP inhibitor. We have previously shown that Doxy inhibitsMMP activity and vascular smooth muscle cell migration invitro. We hypothesized that Doxy would decrease MMP activity invivo and inhibit the development of IH in a rodent model of vascular injury. Doxy (400mg/pellet) was delivered by a slow-release pellet implanted 3days prior to or at the time of balloon angioplasty (BA) of the common carotid artery in female rats. At 14days post-BA, intima-to-media (I:M) ratios were 0.77±0.21 and 1.04±0.32 in the Doxy treated groups, respectively, compared to 1.25±0.26 in the control group (P = not significant; n=3). Additionally, the tested dose of Doxy in either group had no inhibitory effect on membrane type 1-MMP or MMP-2 tissue levels, as measured by immunohistochemistry, or on systemic levels of MMP, as measured by total MMP serum levels using enzyme-linked immunosorbent assay. At 14days post-BA, VSMC proliferation in the injured artery was increased to Doxy treatment prior to and at the time of surgery (23.5±3.4 and 27.2±3.9%, respectively), compared to control (11.4±0.4%; n=3), as measured by proliferating cellular nuclear antigen immunostaining. In our invivo model of vascular injury, systemic Doxy administration prior to or at the time of vascular injury does not significantly hinder the progression of IH development. Additional doses and routes of administration could be examined in order to correlate therapeutic serum levels of Doxy with effective MMP inhibition in serum and arterial tissue. However, alternative drug delivery systems are needed in order to optimize therapeutic administration of targetedMMP inhibitors for the prevention of IH development.

Differential effects of saturated and unsaturated fatty acids on vascular reactivity in isolated mesenteric and femoral arteries of rats.

Free fatty acid (FFA) intake regulates blood pressure and vascular reactivity but its direct effect on contractility of systemic arteries is not well understood. We investigated the effects of saturated fatty acid (SFA, palmitic acid), polyunsaturated fatty acid (PUFA, linoleic acid), and monounsaturated fatty acid (MUFA, oleic acid) on the contractility of isolated mesenteric (MA) and deep femoral arteries (DFA) of Sprague–Dawley rats. Isolated MA and DFA were mounted on a dual wire myograph and phenylephrine (PhE, 1–10 µM) concentration-dependent contraction was obtained with or without FFAs. Incubation with 100 µM of palmitic acid significantly increased PhE-induced contraction in both arteries. In MA, treatment with 100 µM of linoleic acid decreased 1 µM PhE-induced contraction while increasing the response to higher PhE concentrations. In DFA, linoleic acid slightly decreased PhE-induced contraction while 200 µM oleic acid significantly decreased it. In MA, oleic acid reduced contraction at low PhE concentration (1 and 2 µM) while increasing it at 10 µM PhE. Perplexingly, depolarization by 40 mM KCl-induced contraction of MA was commonly enhanced by the three fatty acids. The 40 mM KCl-contraction of DFA was also augmented by linoleic and oleic acids while not affected by palmitic acid. SFA persistently increased alpha-adrenergic contraction of systemic arteries whereas PUFA and MUFA attenuated PhE-induced contraction of skeletal arteries. PUFA and MUFA concentration-dependent dual effects on MA suggest differential mechanisms depending on the types of arteries. Further studies are needed to elucidate underlying mechanisms of the various effects of FFA on systemic arteries.

Vasoactive properties of Ceiba pentandra in porcine coronary artery and different conductance and resistance vessels from rats: A role of nitric oxide

Background: Ceiba pentandra (L.) Gaertner (Malvaceae) a plant widely spread in the world, particularly in sub-Saharan Africa where it is used to handle several pathologies like high blood pressure without scientific evidence by experimental scientific works. Aim and Objective: The purpose of this study is to show how a hydroethanolic leaves extract of Ceiba pentandra (FCP) produces relaxant effects in porcine coronary, rat mesenteric artery, carotid, femoral arteries, and thoracic aorta and to determine the mechanisms which lie beneath this effect. Materials and Methods: Porcine coronary, rat mesenteric, carotid, and femoral arteries and thoracic aorta rings were suspended in organ chambers for recording of changes in isometric forces. Rings with endothelium were incubated or not with L-nitroarginine to block nitric oxide (NO) synthase, manganese (III) tetrakis(1-methyl-4-pyridyl)porphyrin, polyethylene glycol catalase (CAT), an inhibitors of intracellular production reactive oxygen species (ROS); CAT, an inhibitor of extracellular ROS; wortmannin, an inhibitor of redoxsensitive pathway phosphoinositide 3-kinase (PI3 kinase)/Akt; (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo [3,4-d] pyrimidine), an inhibitor of Src kinase; apamin, an inhibitor of small conductance potassium channels calcium dependent (SKCa) and tram-34, an inhibitor of intermediary conductance potassium channels calcium dependent (IKCa); and indomethacin, an inhibitor of cyclooxygenase before contraction with U46619 or phenylephrine and a concentration-relaxation curve to FCP. Results: Some experiments show that endothelium was taken away before contraction with U46619 and concentration relaxation to FCP. The hydroethanolic leaves extract of C. pentandra produces a vasodilatory result in porcine coronary artery pre-contracted with U46619. This effect is endothelium dependent and is mediated by NO. FCP generates, as well, vasorelaxant results in superior mesenteric arteries, carotid arteries, thoracic aorta, and femoral arteries from rat. C. pentandra generates vascular relaxation which can be the explanation of the benefic effect of this plant in the treatment of high blood pressure (HBP) in Africa. Conclusion: C. pentandra holds vasorelaxants properties on pig coronary artery, thoracic aorta, the main superior mesenteric artery, and femoral and carotid artery from rat justifying its utilization in the treatment of the arterial HBP. This effect necessitates the presence of a functional endothelium and passes by the redox-sensitive pathway Src kinase and PI3-kinase/Akt.

Usefulness of a Newly Developed Ultrasonic Microdissector in Neurosurgery: A Preliminary Experimental Study.

Dissection and division of tissues are widely performed in microscopic neurosurgery, especially in brain tumor resection. Dissection maneuvers can be divided into two types: sharp dissection with microscissors and blunt dissection using a dissector. It is essential to use the appropriate method according to the intraoperative situation and conditions. Therefore, specific tools for each type of dissection maneuver are required. We developed an ultrasonic microdissector, a newly designed tool that functions as both microscissors and dissector to further advance brain tumor surgery. This preliminary experimental study was performed to evaluate the usefulness of this new device. Solfy F (J. Morita Mfg. Corp., Kyoto, Japan), a dental ultrasonic instrument, was used to provide power in this study. Two experiments were performed. The first one involved touching the brain parenchyma of a pig cadaver with the tip of the ultrasonic microdissector under various conditions to investigate its side effects. In the second experiment, the rat femoral artery, vein, and nerve were dissected from surrounding structures using a prototype of the ultrasonic microdissector. The effects of this device were then investigated histologically. The amount of tissue damage was greater with the higher ultrasonic power. No irrigation and a long manipulation time also affected tissue degeneration. Dissection using the ultrasonic microdissector was superior to conventional dissection methods in terms of time (p < 0.05) and safety without any additional histologic damages. The newly developed ultrasonic microdissector can dissect soft tissue without damage to the surrounding tissue. Further studies are required to determine the optimal intensity for its clinical use.

Huayu Tongmai Granules protects against vascular endothelial dysfunction via up-regulating miR-185 and down-regulating RAGE.

Objective: Receptor of advanced glycation end products (RAGE) is a membrane protein that contributes to the initiation and progression of diabetic vascular complications, which is reported as a target of miR-185. Huayu Tongmai Granules is a Chinese herbal compound that is capable of treating diabetic angiopathy. The present study was designed to explore the molecular biological mechanism by which Huayu Tongmai Granules protects against diabetic angiopathy.Methods: The rat model of diabetes and hyperglucose cell model were established. The blood glucose was detected to verify whether the model was successfully established. Besides, serum nitric oxide (NO) and reactive oxygen species (ROS) concentrations of the rats in each group were determined. The quantitative real-time PCR analysis was performed to examine the mRNA expression levels of miR-185 and other miRNAs in femoral artery of rats or human umbilical vein endothelial cell line. Additionally, the protein levels of RAGE or Bax were determined using Western blotting. Cell apoptosis was determined by terminal dUTP nick-end labeling assay or flow cytometry.Results: In the present study, we found that Huayu Tongmai Granules significantly decreased blood glucose and serum ROS and up-regulated serum NO concentration. MiR-185 was low-expressed in diabetic rats; however, Huayu Tongmai Granules intervention up-regulated miR-185. Stable overexpression of miR-185 directly suppressed the expression of RAGE and further suppressed endothelial cell apoptosis.Conclusion: Huayu Tongmai Granules appears to have a therapeutic effect on diabetic angiopathy that is most probably mediated by miR-185/RAGE axis.

Phospholipase Cγ2 Signaling Cascade Contribute to the Antiplatelet Effect of Notoginsenoside Fc.

Scope: Bleeding, the main drawback of clinically used chemical anti-thrombotic drug is resulted from the unidirectional suppression of platelet activity. Therefore, dual-directional regulatory effect on platelet is the main preponderance of Panax notoginseng over these drugs. The dual-directional regulatory effect should be ascribed to the resourceful Panax notoginseng saponins (PNS). Clarifying the mechanism of main PNS in both inhibiting and promoting platelet aggregation will give a full outlook for the dual-directional regulatory effect. The present study is aimed at explaining the mechanism of Notoginsenoside Fc (Fc), a main PNS, in inhibiting platelet aggregation.Methods: In the in vitro study, after incubating platelets with Fc and m-3M3FBS, platelet aggregation was triggered by thrombin, collagen or ADP. Platelet aggregation was measured by aggregometer. Phospholipase Cγ2 (PLCγ2) and protein kinase C (PKC) activities were studied by western blotting. Diacylglycerol (DAG), thromboxane B2 (TXB2) and 1,4,5-inositol trisphosphate (IP3) concentrations were measured by corresponding ELISA kits. Calcium concentrations ([Ca2+]) were estimated through the fluorescence intensity emitted from Fluo-4. In the in vivo study, thrombus model was induced by FeCl3. The effect of Fc on thrombosis was evaluated by measurement of protein content and observation of injured blood vessel.Results: thrombin, collagen and ADP induced platelet aggregation were all suppressed by incubating platelets with Fc. Platelet PLCγ2 and subsequent DAG-PKC-TXA2 and IP3 were down-regulated by Fc as well. However, the basal [Ca2+] in platelet was not altered by Fc. Nevertheless, thrombin triggered activation of PLCγ2 and subsequent DAG-PKC-TXA2 and IP3-[Ca2+] were all abolished by Fc. Fc also attenuated platelet aggregation and PLCγ2 signaling activation induced by PLC activator, m-3M3FBS. In the in vivo study, FeCl3 induced thrombosis in rat femoral artery was significantly alleviated by administration of Fc.Conclusion: The results above suggested the antiplatelet and antithrombotic effects of Fc are carried out through oppression of PLCγ2 and subsequent DAG-PKC-TXA2 and IP3-[Ca2+]. The present study provided theoretical support for new anti-thrombotic drug exploitation by Panax notoginseng.

In vivo self-assembly of small diameter pulmonary visceral pleura artery graft

BackgroundThere is a significant clinical need for small vascular grafts <1 mm in diameter. Materials and methodsThe structure and composition of swine pulmonary visceral pleura (PVP) were investigated. Two processes, glutaraldehyde (GA) crosslink and decellularization (dc) plus GA crosslink, were used to inhibit the immune response. The thrombosis-resistance of the GA-crosslinked PVP (GA-PVP) was determined with in vitro and in vivo studies. Small vessel grafts with 0.7 diameter mm were constructed using the GA-PVP and surgically interposed in the femoral artery of rats for up to 24 weeks. Blood flow in the GA-PVP grafts were measured and ex vivo vascular reactivity of the prostheses were evaluated along with immuno-histological analysis. ResultsThe GA-PVP mesothelium contains abundant glycocalyx-like substance and a smooth surface. The mechanical properties of the GA-PVP were similar to the femoral artery of rat in the range of physiological pressures. The in vitro and in vivo studies confirmed poor platelet adhesion on the GA-PVP mesothelial surface in comparison with dc processed PVP (dc-PVP). Patency of the GA-PVP prostheses in femoral arteries of rats was 86% in the 24 weeks postoperative period while patency of dc-PVP in femoral arteries of rats was 33% at 1 week postoperative period. Blood flow in the GA-PVP prostheses were not statistically different than the contralateral femoral artery. Biomarkers of neo-endothelial cells, neo-media smooth muscle cells, and extracellular matrices were observed in the GA-PVP prostheses. The significant agonists-induced vasoconstriction and endothelium-dependent vasodilation were apparent at 12 weeks and further amplified in the 24 weeks postoperative, which suggests self-assembly of functional neo-endothelium and neo-media. ConclusionsThe high patency and functionality of the small grafts suggest that the GA-PVP is a promising prosthetic biomaterial for vascular reconstructions. Statement of SignificanceSmall artery graft (diameter <1 mm) in the peripheral circulation that functionally arterializes has not been possible primarily due to thrombosis. Our findings indicate that lung visceral pleura may address thrombogenicity as the major pitfall in small diameter grafts. Here, grafts of 0.7 mm diameter were constructed from swine pulmonary visceral pleura (PVP) and implanted into femoral artery position of rats up to 24 weeks. The total patency of grafts in femoral arteries of rats was 86% in the 24-week period. The neo-endothelial and -medial layers were assembled in the grafts as evidenced by robust biomarkers of endothelial cells, smooth muscle cells, and extracellular matrices observed in the grafts. Agonists-induced vasoconstriction and endothelium-dependent vasodilation were apparent at 12 weeks and were amplified at 24 weeks. The high patency of the small grafts suggests that the PVP is a promising prosthetic biomaterial for vascular reconstructions.

Torsion Does Not Affect Early Vein Graft Patency in the Rat Femoral Artery Model.

Torsion of vein grafts is a commonly cited reason for graft failure in clinical setting. Many microsurgery training courses have incorporated vein graft procedures in their curricula, and vein graft torsion is a common technical error made by the surgeons in these courses. To improve our understanding of the clinical reproducibility of practicing vein graft procedures in microsurgery training courses, this study aims to determine if torsion can lead to early vein graft failure in nonsurvival surgery rat models. Sprague-Dawley rats were divided into five cohorts with five rats per cohort for a total of 25 rats. Cohorts were labeled based on degree of vein graft torsion (0, 45, 90, 135, and 180 degrees). Torsion was created in the vein grafts at the distal arterial end by mismatching sutures placed between the proximal end of the vein graft and the distal arterial end. Vein graft patency was then verified 2 and 24 hours postoperation. All vein grafts were patent 2 and 24 hours postoperation. At 2 hours, the average blood flow rate measurements for 0, 45, 90, 135, and 180 degrees of torsion were 0.37 ± 0.02, 0.38 ± 0.04, 0.34 ± 0.01, 0.33 ± 0.01, and 0.29 ± 0.02 mL/min, respectively. At 24 hours, they were 0.94 ± 0.07, 1.03 ± 0.15, 1.26 ± 0.22, 1.41 ± 0.11, and 0.89 ± 0.15 mL/min, respectively. Torsion of up to 180 degrees does not affect early vein graft patency in rat models. To improve the clinical reproducibility of practicing vein graft procedures in rat models, we suggest that microsurgery instructors assess vein graft torsion prior to clamp release, as vessel torsion does not seem to affect graft patency once the clamps are removed.

A Comparative Analysis of the Effects of Melatonin and Nimodipine on Vasospasm

Objective: In this study, we aimed to compare the efficacy of nimodipine and melatonin in a rat femoral artery vasospasm model. Material and Methods: The rats were divided into five groups as follows: Group I (n=8): control group, Group II (n=8): vasospasm group, Group III (n=8): vasospasm + melatonin group, Group IV (n=8): vasospasm + nimodipine group, Group V (n=8 rats): vasospasm + melatonin + nimodipine group. At the end of the 7 th day, the femoral arteries were excised and histopathologically examined under light microscope. Results: Vascular wall of vasospasm group was relatively thicker when compared with the control group. There was a statistically significant difference between the wall thickness of Group II and Group III, IV and V. The maximum reduction of wall thickness was observed in Group V. There was no statistically significant difference in lumen diameter between Group I and Group IV. The lumen diameter was found to be increased in Group III, IV and V when compared with Group II. Conclusion: The development of experimental peripheral vasospasm has been reduced by the melatonin and nimodipine and their effect was increased when they were used concomitantly.

Comparison of Ca2+-dependent Cl-channels blockade and endothelium-derived constricting factor in norepinephrine-induced contraction of rat femoral artery

Comparison of Ca2+-dependent Cl-channels blockade and endothelium-derived constricting factor in norepinephrine-induced contraction of rat femoral artery

Morphometric Analysis of Dose-dependent Effect of Progesterone on Experimental Vasospasm-induced Rat Femoral Arteries.

Objective:Our aim of this study was to determine effective doses of progesterone which has a vasodilatory effect during the early stage of vasospasm. Cerebral vasospasm (CV) is a predominant cause of morbidity and mortality which develops following subarachnoidal hemorrhage (SAH). Etiopathogenesis of CV is multifactorial. Despite many previously performed studies on this issue, the mechanism by which blood and blood products in the subarachnoidal space induce CV has not been clarified yet.Materials and Methods:In our study, we used “Rat Femoral Artery Vasospasm Model” introduced by Okada et al. Thanks to easy procurement and maintenance of rats. Rats were divided into four groups as: Group 1 (n = 8; control group), Group 2 (n = 8; vasospasm group), Group 3 (n = 8; vasospasm + 3 mg/kg progesterone group), and Group 4 (n = 8; vasospasm +15 mg/kg progesterone group). Progesterone which is an endogenously synthesized natural steroid was preferred in our study. Progesterone increases the production of vasodilatory epoxyeicosatrienoic acid by acting on its binding sites termed as pregnane X receptor. It decreases the intracellular influx of Ca2+ by blocking the functioning of L-type channels in smooth muscle cells. It manifests another vasodilatory effect by decreasing expression of TxA2 receptor. In our study, at the end of the 7th day, where the most intense vasospasm is seen, 1 cm pieces were excised from the femoral arteries and histopathologically examined under light microscope.Results:Vascular walls of three vasospasm-induced groups were relatively thicker when compared with the control group. Drug-treated groups were not different from each other. Vascular walls of the groups treated with lower and higher doses of the drug were thinner when compared with the vasospasm group without any statistically significant difference between groups (P > 0.05). Luminal cross-sectional areas of the drug-treated groups did not differ from each other. Mean luminal cross-sectional areas of the control and the drug-treated groups were larger than that of the vasospasm group without any statistically significant intergroup difference (P > 0.05).Conclusion:Based on the results of our study, progesterone did not exert protective effects on vascular wall thickness, while histopathological examination of luminal cross-sectional areas revealed its vasodilatory effects without any statistically significant difference between groups. Starting from the study results obtained, we think that its potential use as a preventive agent against the development of post-SAH CV requires conduction of multicentered, placebo-controlled, randomized, and double-blind studies.

Recombinant batroxobin-coated nonwoven chitosan as hemostatic dressing for initial hemorrhage control

The choice of hemostat is determined by the situation and the degree of hemorrhage. One common hemostat, the nonwoven dressing, is easy to handled and controls severe bleeding on wider wounds. In this study, chitosan-based nonwoven dressings with recombinant batroxobin (rBat) were used as efficacious hemostatic dressing agents. Hemostatic agents need to absorb blood quickly in the early stages of blood coagulation cascade to rapidly and effectively control of excessive hemorrhages. To date, most studies of hemostatic agents focused on a single material and hemostats composed of multiple materials have not been studied sufficiently. Thus, we made a chitosan dressing coated with rBat and investigated the microstructure, mechanical properties, hemostatic efficacy, and clotting properties of the coated dressing. Our results showed that the rBat had a synergetic effect on chitosan that improved blood coagulation. Furthermore, the dressing had excellent bleeding control in an Sprague-Dawley (SD) rat femoral artery hemorrhage model. In conclusion, hemostasis can be improved by combining a chitosan-based nonwoven dressing with other agents, and rBat-coated chitosan-based nonwoven dressings have enormous potential to improve blood coagulation.

The enhancement of serotonin-induced contraction of rat femoral artery is mediated by angiotensin II release from intact endothelium

We have performed an in vitro study on isolated intact or denuded femoral artery (FA) of healthy, diabetic, and/or rats submitted to the FA occlusion. The aim was to determine the contribution of endothelium and endothelial dysfunction (ED) on serotonin-induced action in FA. Further, the contribution of angiotensin II and cyclooxygenase products of arachidonic acid was investigated. A marker of ED, vWF was measured in animal serum. Serotonin induced contraction-dependent contraction of isolated FA, which was increased in preparations with endothelium. Pathological conditions such as endothelial denudation, nicotine-induced ED, diabetes or occlusion of FA reduced serotonin-induced contraction. Comparable reduction of serotonin-induced contraction was achieved after inhibition of AT1 receptors with losartan in isolated FA with intact endothelium. Our results demonstrate that angiotensin II contributes to the enhancement of serotonin-induced contraction of femoral arteries with intact endothelium. This increase is attenuated by endothelium removal, nicotine treatment, vascular occlusion, and/or hyperglycemia.

Histological Changes in the Rat Femoral Artery Following the Use of the Empty-and-Refill Test.

This study examines the effects of the empty-and-refill patency test on rat femoral arteries in the longer postoperative time period. A simple arterial anastomosis was performed bilaterally on 20 rats. The empty-and-refill test was performed unilaterally in all rats, leaving the contralateral artery as an internal control. Rats were divided into two cohorts of 10 rats and survived for 48 hours and 2 weeks. Vessel patency was assessed prior to closing and immediately prior to sacrifice. The femoral arteries were harvested bilaterally and hematoxylin and eosin stains were performed. The femoral artery distal to the anastomosis in the region of the empty-and-refill test was histologically evaluated. All vessels were patent at the time of sacrifice. There was no statistical difference in the numeric scoring between the experimental and control vessels in the 48-hour cohort. Almost all vessels harvested at 48 hours showed endothelial cell loss distal to the anastomosis regardless of whether they underwent the empty-and-refill test. The only statistically significant difference in the 2-week cohort was an increase in adventitial smooth muscle proliferation in the experimental group. There were no other statistically significant results between the experimental and control groups at 2 weeks. An overall comparison of both cohorts revealed a statistically significant increase in endothelial cell number and intimal proliferation by 2 weeks postsurgery. The empty-and-refill test does not compromise rat femoral artery anastomotic patency, nor does it produce histological damage either 48 hours or 2 weeks postsurgery.

Morphometric Analysis of the Effects of Manuka Honey on Vasospastic Femoral Arteries in Rats: An Experimental Study.

Objectives:The aim of this study was to determine if Manuka honey, a potent anti-inflammatory and antioxidant agent, had any effect on the development of vasospasm in an experimental subarachnoidal hemorrhage model constructed in rat femoral arteries.Methods:Twenty-four Wistar Albino strain rats were divided into 3 groups: Group 1 was the control group (n=8), Group 2 was the vasospasm group (n=8), and group 3 was the treatment group (n=8). The wall thickness (W) of the femoral arteries and the luminal diameter (L) were measured using morphometric methods. The data were analyzed with statistical software. The Mann-Whitney U-test was used to compare independent groups and Bonferroni post hoc analysis was used for multiple comparison tests. Significance for all of the results was established at p<0.05.Results:A statistically significant intergroup difference was detected in the mean L and W (p<0.001, p=0.001, respectively). The mean L value in Group 2 was statistically significantly less than that of Groups 1 and 3, while the mean W value was significantly greater (p<0.001 for all). However, no statistically significant difference was detected between Groups 1 and 3 with respect to the mean L and W values (p=0.064, p=0.954, respectively).Conclusion:Manuka honey exerts an antioxidant and anti-inflammatory effect via inhibition of inflammatory cytokines, including plasma tumor necrosis factor alpha, interleukin (IL)-1 beta, IL-6, and the lipid peroxidation level. This study statistically demonstrated that the anti-inflammatory and antioxidant properties of Manuka honey successfully inhibited the development of vasospasm in an experimentally induced vasospasm model in the femoral arteries of rats.

The effects of adenosine on rat femoral artery in pathological models related to peripheral artery disease

Background: Peripheral artery disease (PAD) of lower limbs is a chronic disease that is associated with the occurrence of endothelial dysfunction and further progression of atherosclerosis in the affected arteries. Adenosine, a purine nucleoside, is commonly released during hypoxia with resulting improvement of the local blood flow, which is why it could be used as a potential therapeutic option in the treatment of PAD. The aim of this study was to investigate the possible therapeutic role of adenosine in the peripheral artery disease, examined through its effect on the isolated rat femoral artery, which was randomly submitted to occlusion, in both healthy and diabetic animals. Also, it was of interest to examine a possible role of endothelium in this process.

Microvascular Anastomosis Using Only 2-Throw Reef-Knots: A Technical Note.

In macrosurgery creating a knot with at least three throws is an established practice. The potential disadvantages of this practice in microsurgery include the following: the direction of the cut ends interfere with the suture line, unbalanced nature of knot disturbs the apposition of delicate vessel ends and the excessive knot weight. A reef knot with only 2 throws may thus be a better alternative. We have described our technique of end to end anastomosis with 2-throw reef knots in a rat femoral artery model using one way up method. Judging from the surgical outcome the practice of two throw reef knot seems feasible and appealing.