Necrosis Of Smooth Muscle Cells Research Articles

Modeling of rabbit femoral artery occlusion by high-intensity focused ultrasound

One of the effective methods of artery and vein occlusion used in experimental studies and in clinical practice for certain diseases is local exposure of vessels to high-intensity focused ultrasound (HIFU). The wide use of this method in our country is limited by the lack of appropriate domestic equipment. At the Peter the Great St. Petersburg Polytechnic University, in the Laboratory of Ultrasound Technologies of the Center for Advanced Research, a stand for HIFU effects on various biological objects has been developed. There is no experience in using this device in angiology yet. The purpose of our research was to study the possibility of using Medusa 008, a high-tech mobile medical device designed for ultrasound diagnosis and personalized HIFU therapy, to model vascular occlusion and stop blood flow during irradiation. Materials and methods. The object of the study is the femoral artery of a rabbit. The source of HIFU is Medusa 008, the high-tech mobile medical device designed for ultrasound diagnostics and personalized HIFU-therapy with radiation frequency of 2 MHz (prototype). The following irradiation modes were used in the research: irradiation duration - 50 ms, pause between exposures – 10 ms, number of pulses – 20, 30, 40. The following energy values corresponded to these modes: 58 J, 87 J, 116 J. Irradiation of the femoral artery of an anesthetized rabbit was performed percutaneously. We used ultrasound to visualize the arteries and measure the blood flow velocity. According to ultrasound data, after HIFU irradiation, blood flow in the artery stopped. The factor contributing to arterial occlusion is the cessation of blood flow during irradiation. A histological examination of the area of the irradiated artery revealed structural changes in all layers of the vascular wall. Results. HIFU irradiation with intensity of 87 and 116 J has a significant dose-dependent destructive effect on the muscular arterial wall. The more intense damaging irradiation (116 J) causes smooth muscle cell necrosis. The time of direct influence on the vessel wall structures did not exceed 3 sec. During the experiment, we found that HIFU in the used modes causes temperature increase up to 45–60 оC, which is enough for thermal damage of cells in the irradiation zone. Conclusion. Thus, as a result of the above experiments, it was shown that Medusa 008, the high-tech mobile medical device designed for ultrasound diagnostics and personalized HIFU-therapy can be used to simulate vascular occlusion.

Association between intracerebral hemorrhage and cholesterol levels, and molecular mechanism underlying low cholesterol inhibiting autophagy in cerebral arterial smooth muscle cells leading to cell necrosis

BackgroundAn association between cholesterol and intracerebral hemorrhage (ICH) has been reported, but the mechanism is unclear. MethodsIn this cross-sectional study, participants aged 50–75 years were selected using multistage stratified cluster sampling. All samples completed a questionnaire (age, gender, medication, etc.) and were examined (blood lipid, height, blood pressure, etc.) for risk factors. Multivariable logistic regression was used to analyze the association between cholesterol levels and ICH risk, after adjusting for age, smoking, hypertension, and other factors. We cultured rat cerebral artery smooth muscle cells at different cholesterol concentrations. The autophagy pathway was identified by transcriptome sequencing. The results were then validated using real-time polymerase chain reaction and western blot. ResultsWe included 39,595 patients, among whom 286 had ICH. The study showed that a low level of low-density lipoprotein cholesterol (LDL-C) was a risk factor of ICH (odds ratio 2.912, 95% confidence interval 1.460–5.806; P = 0.002). Cell experiments showed that lower cholesterol levels could significantly induce rat cerebral artery smooth muscle cell necrosis. In low-cholesterol groups, expression of the autophagy marker LC3 protein was significantly decreased and p62 protein was significantly increased. In western blot and comparison with the control group, the low cholesterol PI3K/Akt/mTOR signaling pathway was significantly activated in the autophagy pathway, resulting in its inhibition, which in turn led to smooth muscle cell death. ConclusionLow cholesterol levels may inhibit autophagy through PI3K/Akt/mTOR signaling and induce arterial smooth muscle cell necrosis, thereby increasing the risk of ICH.

Establishment of an animal model to study the effects of amputation on the cardiovascular system

Lower limb amputation is a significant change in body structure. Loss of muscle, blood vessels, and blood leads to a redistribution of blood flow and changes in resistance at the end of blood vessels. In view of the significant increase in the prevalence of cardiovascular disease after lower limb amputation, the mechanism of which is still unclear, this study aims to establish an animal research model that can verify and explore the effects of amputation on cardiovascular system, and provide the experimental basis for subsequent animal experiments when exploring the effect of different amputation levels on the cardiovascular system. SPF New Zealand rabbits were divided into normal group ( n = 6) and amputation group ( n = 6). The amputation group was treated with above-knee amputation. The changes of low-density liptein cholesterol (LDL-C) and total cholesterol (TC) in serum of all the rabbits were monitored regularly after the surgery. The arterial pathological examination was conducted after the experimental rabbits were executed. The results showed that compared with the normal group, serum LDL-C content and TC content in the amputation group were significantly increased ( P<0.05); The blood vessels of the amputated rabbits had pathological changes such as degeneration and necrosis of smooth muscle cells in the middle membrane layer and rupture of elastic fibers. At the abdominal aorta and aortic arch, the elastic fiber area expression percentage (EFEP) of the experimental group was significantly lower than that of the normal group. The results suggest that the cardiovascular system of rabbits has the tendency of decreased arterial elasticity and lipid deposition in blood after amputation, indicating that the animal research model on the effect of amputation on the cardiovascular system has been successfully established, and can provide an experimental platform for further study on the mechanism of the effect of amputation on the cardiovascular system.

Reducing Endogenous Labile Zn May Help to Reduce Smooth Muscle Cell Injury around Vascular Stents.

Vascular stent service involves complex service environments and performance requirements, among which the histocompatibility of the stent could seriously affect the therapeutic effect. In the pathology of vascular disease, the thin fiber cap is easily ruptured, exposing the necrotic core below, and triggering a series of dangerous biochemical reactions. In contrast, the thin neointima, considered an essential structure growing on the stent, may evolve into vulnerable plaque structures due to lesions induced by the stent. Therefore, the reduction of necrosis around the stent below the thin neointima is indispensable. In this work, different cell model experiments suggested that the content of endogenous labile Zn positively correlated with cell injury. Zinquin-Zn fluorescence experiments and zinc ion channels research suggested that the change in the content of endogenous labile Zn in smooth muscle cells is affected by different stent coatings. The content of endogenous labile Zn in cells negatively correlated with cell viability. Animal experiments indirectly verified the increase in endogenous labile Zn by detecting the expression of Zn regulatory protein (metallothionein) in the necrotic tissues. Reducing the content of endogenous labile Zn may favor a reduction in smooth muscle cell injury and necrosis. This biochemical mechanism is effective in improving the therapeutic effect of vascular stents.

Penile Prosthesis Implantation in Refractory Ischaemic Priapism: Patient Selection and Special Considerations

Ischemic priapism accounts for more than 95% of all priapic episodes. It has to be considered a urological emergency because its time extension may lead to necrosis of smooth muscle cells of the corpora cavernosa, resulting in a complete erectile dysfunction, penile shortening and loss of girth. In the present systematic review, we perform an up-to-date literature search for patients suffering from refractory ischemic priapism who undergo penile prosthesis implantation with particular interests to the patients characteristics. The conservative management of the priapic episode consists of a sympathomimetic agent in the first istance. Failure or recurrence of priapism following these conservative measures is an indication for surgical management. Shunt procedures between the corpora cavernosa and the neighbouring structures are often used first line; however, in refractory ischemic priapism the success rate is minimal. In such cases (>48 h) an indication of immediate placement of a penile prosthesis could be the best solution.

Immunobiology of Atherosclerosis: A Complex Net of Interactions.

Cardiovascular disease is the leading cause of mortality worldwide, and atherosclerosis the principal factor underlying cardiovascular events. Atherosclerosis is a chronic inflammatory disease characterized by endothelial dysfunction, intimal lipid deposition, smooth muscle cell proliferation, cell apoptosis and necrosis, and local and systemic inflammation, involving key contributions to from innate and adaptive immunity. The balance between proatherogenic inflammatory and atheroprotective anti-inflammatory responses is modulated by a complex network of interactions among vascular components and immune cells, including monocytes, macrophages, dendritic cells, and T, B, and foam cells; these interactions modulate the further progression and stability of the atherosclerotic lesion. In this review, we take a global perspective on existing knowledge about the pathogenesis of immune responses in the atherosclerotic microenvironment and the interplay between the major innate and adaptive immune factors in atherosclerosis. Studies such as this are the basis for the development of new therapies against atherosclerosis.

Dysfunction of the arteriovenous fistula for hemodialysis as a consequence of venous neointimal hyperplasia and treatment strategies

One of the main problems related to inadequate planning of vascular access is dysfunction during maturation. Arteriovenous fistula dysfunction is most often a consequence of neointimal hyperplasia. Important causes for initial dysfunction of the fistula include narrow lumens of the arteries and veins used for anastomosis, damage to the vascular endothelium during fistula creation, previous venipuncture, postoperative development of venous collaterals, the impact force of friction on the arteriovenous anastomosis, a genetic predisposition for development of vascular stenosis, neointimal hyperplasia and previously persistent venous neointimal hyperplasia. Any damage to the endothelium is a stimulus for neointimal hyperplasia. During surgery for creating the fistula, endothelial cells separate on the intima, edema appears, fibrin is deposited, leukocytes and platelets infiltrate. Spotted edema and necrosis of smooth muscle cells appear in the media. In order to determine an adequate therapeutic strategy, the pathogenesis of intimal hyperplasia has been widely considered from different aspects. It is currently based on preoperative preservation of veins and careful selection of blood vessels, percutaneous transluminal angioplasty or surgical revision. Nevertheless, no current therapeutic strategies provide appropriate recommendations to improve maturation of the arteriovenous fistula. Notwithstanding considerable knowledge about the pathogenesis of venous neointimal hyperplasia, currently no prophylactic treatments would reduce its progression.

New Insights into the Role of Inflammation in the Pathogenesis of Atherosclerosis.

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipids, smooth muscle cell proliferation, cell apoptosis, necrosis, fibrosis, and local inflammation. Immune and inflammatory responses have significant effects on every phase of atherosclerosis, and increasing evidence shows that immunity plays a more important role in atherosclerosis by tightly regulating its progression. Therefore, understanding the relationship between immune responses and the atherosclerotic microenvironment is extremely important. This article reviews existing knowledge regarding the pathogenesis of immune responses in the atherosclerotic microenvironment, and the immune mechanisms involved in atherosclerosis formation and activation.

A novel PDGF receptor inhibitor-eluting stent attenuates in-stent neointima formation in a rabbit carotid model.

A novel drug-eluting stent (DES) is required to target vascular smooth muscle cells (SMCs) without harming endothelial cells (ECs). Platelet-derived growth factor (PDGF) is critical for the proliferation and migration of SMCs. Sunitinib [a PDGF receptor (PDGFR) tyrosine kinase inhibitor]-eluting stents may therefore inhibit neointimal formation. The aim of the present study was to examine the stent-based delivery of sunitinib in a rabbit carotid model; in addition, the effects of sunitinib were evaluated in vitro. Local administration of sunitinib markedly reduced neointimal formation without delaying re-endothelialization in the carotid artery model. In vitro, sunitinib inhibited SMC proliferation; however, no effects were observed on ECs. Sunitinib caused necrosis of SMCs. In addition, sunitinib attenuated PDGF-stimulated SMC migration in a scratch wound assay and inhibited α-SMA cytoskeleton polymerization. Furthermore, sunitinib inhibited PDGF-induced phosphorylation of extracellular signal-regulated kinase in vitro and in vivo. Therefore, this novel DES may be a potential strategy for the treatment of vascular disorders.

CARD9 mediates necrotic smooth muscle cell-induced inflammation in macrophages contributing to neointima formation of vein grafts.

Inflammation plays an important role in the neointima formation of grafted veins. However, the initiation of inflammation in grafted veins is still unclear. Here, we investigated the role and underlying mechanism of an innate immunity signalling protein, caspase-associated recruitment domain 9 (CARD9) in vein grafts in mice. In early murine vein grafts, we observed robust death of smooth muscle cells (SMCs), which was accompanied by infiltration of macrophages and expression of pro-inflammatory cytokines. Meanwhile, SMC necrosis was associated with the expression of pro-inflammatory cytokines in macrophages in vitro. To explore the mediators of necrotic SMC-induced inflammation in grafted veins from mice, we examined the expression of CARD family proteins and found CARD9 highly expressed in infiltrated macrophages of grafted veins. CARD9-knockout (KO) inhibited necrotic SMC-induced pro-inflammatory cytokine expression and NF-κB activation. Furthermore, CARD9-KO suppressed necrotic SMC-induced expression of VEGF in macrophages. Finally, CARD9-KO decreased neointima formation of grafted veins in mice. The innate immune protein CARD9 in macrophages may mediate necrotic SMC-induced inflammation by activating NF-κB and contributed to neointima formation in the vein grafts.

The effect of SCF and ouabain on small intestinal motility dysfunction induced by gastric cancer peritoneal metastasis.

The interstitial cells of Cajal (ICCs) play an important role in maintaining the normal function of gastrointestinal dynamics. In our previous study, we reported that, in advanced gastric cancer, the frequency of bowel movement is always reduced, due in part to the decreased number of ICCs. To investigate the impact of ICCs in gastric cancer, we established a mouse model of gastric cancer peritoneal metastasis using SGC-7901 gastric adenocarcinoma cells and their supernatant. Then, stem cell factor (SCF) and ouabain were used as therapeutic agents to improve gut dynamics. Our data showed that, compared with the normal mice, treatment with SGC-7901 cells and their supernatant led to a significant reduction of the muscle layer thickness, a decreased number of ICCs, broadened gaps between ICCs and surrounding cells, degeneration and necrosis of smooth muscle cells (SMCs), and infiltration of inflammatory cells. In contrast to SGC-7901 cell and supernatant treatment, SCF intervention caused mild submucosal edema and mitochondrial proliferation in the ICCs and SMCs. Additionally, ouabain treatment led to inflammatory cells infiltration into the submucosa and a decreased volume of ICCs. In conclusion, our data illustrated that, under the condition of gastric cancer peritoneal metastasis, the dysfunction of intestinal peristalsis may be related to pathological changes in ICCs. Moreover, we demonstrated that SCF treatment may help to improve intestinal dynamics by regulating the number and function of ICCs.

Receptor-interacting protein kinase 3 contributes to abdominal aortic aneurysms via smooth muscle cell necrosis and inflammation.

Depletion of medial smooth muscle cell (SMC) is a major pathological characteristic of abdominal aortic aneurysm (AAA), although the mechanism by which these cells are eliminated remains incompletely understood. We reasoned that necroptosis, a recently described form of necrosis mediated by receptor-interacting protein kinase 3 (RIP3), may contribute to AAA pathology through the induction of SMC death and the significant production of inflammatory cytokines. To test the hypothesis that RIP3-mediated necroptosis is actively involved in aneurysm pathogenesis. RIP3 and RIP1 levels were found to be elevated in human AAAs, most noticeably in SMCs. Elevations of RIP3 and SMC necrosis were also observed in the elastase-induced mouse model of AAAs. Deletion of one or both copies of Rip3 prevented AAA formation. By transplanting Rip3(+/-) aortae to Rip3(+/+) mice, we demonstrated that reduced Rip3 expression in arterial wall was the primary cause of aneurysm resistance. In vitro, adenoviral overexpression of RIP3 was sufficient to trigger SMC necroptosis. Protein kinase C-delta contributed to tumor necrosis factor-α-induced SMC necroptosis by regulating Rip3 expression. Furthermore, Rip3 deficiency impaired tumor necrosis factor-α-induced inflammatory gene expression in aortic SMCs, which was at least in part because of attenuation of p65 Ser536 phosphorylation. In vivo, the lack of RIP3 diminished activation of p65 in SMCs, implicating a necrosis independent function of RIP3 in aneurysms. Enhanced RIP3 signaling in aneurysmal tissues contributes to AAA progression by causing SMC necroptosis, as well as stimulating vascular inflammation, and therefore may serve as a novel therapeutic target for AAA treatment.

Pathogenesis of intermediate lesion of human coronary atherosclerosis: lipid pool formation without necrosis and dispersion of intimal smooth muscle cells

Objectives: Proliferation of smooth muscle cells (SMCs) and deposition of lipids by death of macrophage foam cells are key events in atherosclerosis in animal models. However, different processes occur in human atherosclerosis. The purpose of this study is to clarify the pathogenesis of intermediated lesion (preatheroma) of human atherosclerosis, focusing on intimal SMCs and extracellular lipids.

Effects of everolimus on macrophage-derived foam cell behavior.

The purpose of this study was to investigate the effects of everolimus on foam cell (FC) viability, mRNA levels, and inflammatory cytokine production to better understand its potential inhibitory effects on atheroma progression. Human THP1 macrophage-derived FC were formed using acetylated LDL (acLDL, 100 μg/mL) for 72 hours, followed by everolimus treatment (10(-5)-10(-11) M) for 24 hours. FC viability was quantified using fluorescent calcein AM/DAPI staining. FC lysates and media supernatants were analyzed for apoptosis and necrosis using a Cell Death ELISA(PLUS) assay. FC lysates and media supernatants were also analyzed for inflammatory cytokine (IL1β, IL8, MCP1, TNFα) mRNA levels and protein expression using quantitative reverse transcription real-time polymerase chain reaction (QPCR) and a Procarta® immunoassay, respectively. mRNA levels of autophagy (MAP1LC3), apoptosis (survivin, clusterin), and matrix degradation (MMP1, MMP9) markers were evaluated by Quantigene® Plex assay and verified with QPCR. Additionally, hypercholesterolemic rabbits received everolimus-eluting stents (EES) for 28 or 60 days. RAM-11 immunohistochemical staining was performed to compare %RAM-11 positive area between stented sections and unstented proximal sections. Statistical significance was calculated using one-way ANOVA (p≤0.05). Calcein AM/DAPI staining showed that FC exposed to everolimus (10(-5) M) had significantly decreased viability compared to control. FC apoptosis was significantly increased at a high dose of everolimus (10(-5)M), with no necrotic effects at any dose tested. Everolimus did not affect endothelial (HUVEC) and smooth muscle (HCASMC) cell apoptosis or necrosis. Everolimus (10(-5)M) significantly increased MAP1LC3, caused an increased trend in clusterin (p=0.10), and significantly decreased survivin and MMP1 mRNA levels in FC. MCP1 cytokine mRNA levels and secreted protein expression was significantly decreased by everolimus (10(-5) M) in FC. Percentage of RAM-11 positive area exhibited a reduction trend within sections stented with EES compared to unstented proximal sections at 60 days (p=0.09). Everolimus, a potent anti-proliferative agent used in drug-eluting stents and bioresorbable vascular scaffolds, may inhibit atheroma progression and/or promote atheroma stabilization through diminished viability of FC, decreased matrix degradation, and reduced pro-inflammatory cytokine secretion. We explored the effects of everolimus on the behavior of human THP1 macrophage-derived foam cells in culture, including cell viability, mRNA levels, and pro-inflammatory cytokine production. We conclude that everolimus, a potent anti-proliferative agent used in drug-eluting stents/bioresorbable vascular scaffolds, may potentially inhibit atheroma progression and/or promote atheroma stabilization through diminished viability of foam cells, decreased matrix degradation, and reduced pro-inflammatory cytokine secretion.

Pathogenesis of focal cytoplasmic necrosis of the smooth muscle cells in hypertensive rat arterial media.

Hypertensive rat arteries exhibited severe medial smooth muscle cell injury and necrosis. Electron microscopic observations showed the smooth muscle cells of these arteries exhibited characteristics of focal cytoplasmic necrosis forming new cytodemarcating membrane between the healthy cytoplasm and necrotic cytoplasm. When the focal necrotic cytoplasm disappeared from the injured smooth muscle cells, it left it with a moth-eaten leaf-like appearance (moth-eaten necrosis). At an advanced stage of injury, smooth muscle cells changed to islet-like cell bodies with newly formed basement membranes around them, and further islet-like cell bodies and cell debris disappeared leaving lamellar and reticular basement membranes.In hypertensive rats injected with nitroblue tetrazolium (NBT), formazan deposits were observed in the medial cells and nitrotyrosine, a biomarker of peroxynitrite, were immunohistochemically observed in the arterial media. Nick-end positive extranuclear small granular bodies, which might have derived from focal necrotic cytoplasm and nucleus, were detected in the arterial media using DNA nick-end labeling method. Based on electron microscopical and histochemical findings, we conjectured that the focal cytoplasmic necrosis of the smooth muscle cells in the arterial media depended on injury arising from mitochondria-derived oxidants.

Wood smoke condensate had weak proliferation and strong necrotic effects on human airway smooth muscle cells

To investigate the effect of wood smoke condensate (WSC) on proliferation and necrosis of human airway smooth muscle cells (HASMCs). Primary cultured HASMCs between passage 2 and 8 were divided into 3 groups: a control group, a WSC group and a cigarette smoke condensate (CSC) group. The viability of cells was examined by the CCK8 assays. The ratio of cellular proliferative stage (S phase) and cell cycle index were examined by fluorescent-labeled thymidine analogue uptake assays and flow cytometry. The expression of cyclin D1 was detected by quantitative reverse transcriptase polymerase chain reaction (Q-PCR) and Western blot. Cell apoptosis and necrosis were observed by the annexin-V and PI staining. Statistical analysis was performed by using the One-way ANOVA and LSD-t test. Cell viability reached peak at WSC 1 mg/L[(126 ± 12)%] and at CSC 10 mg/L exposure level [(142 ± 11) %] respectively. While at WSC 10 mg/L and CSC 60 mg/L exposure levels, cell viability decreased significantly to 86% and 76%, respectively, as compared with that of the blank control group[(100 ± 0)%] (q = 3.63- 9.33, P < 0.05). In the WSC 1 mg/L group, the cell proliferation ratio and the expression of cyclin D1 protein were (124 ± 20)% and 1.31 ± 0.64, respectively, the differences being significant as compared with the blank control group [(100 ± 0)%, 1.0 ± 0.0] (q = 5.85, 5.91, P < 0.05), while the expression of cyclin D1 mRNA and the percentage of S+G2M phase were 1.18 ± 0.21 and (103 ± 4)%, respectively, not significantly different as compared to the control group [(100 ± 0)%, 1.0 ± 0.0], (q = 1.16, 2.05, P > 0.05). In the CSC 10 mg/L group, the above-mentioned values were (204 ± 45)%, 1.80 ± 0.25, (140 ± 6)%, 1.48 ± 0.2, respectively, which were significantly higher than those in the blank control group (q = 5.38-16.51, P < 0.05) and in the WSC group (q = 3.33-15.35, P < 0.05). However, when HASMCs were exposed to WSC 10 mg/L, the cell death ratio was (13.39 ± 0.15)%, higher than that of the blank control group [(1.57 ± 0.41)%] and the CSC group [(6.61 ± 1.91)%] (q = 18.03, 10.34, P < 0.05). Apoptosis ratio in the CSC 40 mg/L group was [(61.8 ± 10.6)%], higher than that of the blank control group [(0.0 ± 0.0)%] and the WSC group [(1.7 ± 0.4)%] (q = 17.44, 16.95, P < 0.05). Exposure to WSC caused a weak proliferation of HASMCs, but resulted in cell necrosis instead of apoptosis at high doses. There was a slight difference in cell effects between the WSC group and the CSC group.

Histological characteristics and classifications of coarctation of the aorta

Coarctation of the thoracic aorta is defined as a congenital narrowing of the upper part of the descending aorta, adjacent to the place of joining of ductus arteriosum or ligament, which produces a difference in the pressure above the narrowing and below it. One of the most widely accepted classifications of the coarctation is its division on the basis of the age of patients. According to this classification, coarctation is divided into the neonatal and adult type. The neonatal type of coarctation is characterized by the presence of the ductal sling and coarctational shelf placed proximally in relation to the ductal orifice. In newborn babies and younger nurslings, the shelf and neighboring parts of coarctational segment contain ductal tissue. The ductal tissue forms a 'sling' which completely surrounds the juxtaductal aorta. Clinical characteristics of the neonatal type are heart insuficiency at infancy, diffused narrowing of the aortic arch, called tubular hypoplasia, together with the wide open ductus and other congenital heart diseases. In the adult type of coarctation, the histological findings shows cystic medial necrosis. It is characterized by necrosis of smooth muscle cells, presence of cysts in the elastic lamellae filled with basophile mucopolysaccharides, followed by fibrosis with irregular fibroelastic tissue in the media. The adult type is characterized by clearly limited external narrowing of a short aorta segment in the shape of a sandglass, usually in place of the connection of ductus or ligament, or just distal. Concomitant heart diseases are rarely found in this type of coarctation.

SEXUAL ABSTINENCE AND IMMOBILISATION STRESS DECREASED NITRATE + NITRITE CONCENTRATION AND INCREASED NECROTIC OF PENILE CORPUS CAVERNOSUM SMOOTH MUSCLE AND ENDOTHELIAL CELLS OF ADULT MALE MICE

Sexual intercourse in adult people is not only related to reproduction,recreation and better relation but also for maintaining good health. Regular andfrequent sexual intercourse has protective role for cardiovascular disease, malignancyand often related with longevity. On the contrary less frequent sexual intercourse isoften correlated to early death and reproductive organ disorders. One main factorwhich involve in any process related to sexual intercourse is nitric oxide. Thisresearch aims to know the declination of total nitrate and nitrite concentration as themain oxidation product of nitric oxide and necrosis of the endothelial and smoothmuscles of corpus cavernosum after three month sexual intercourse abstinence andstress immobilization.By randomized pretest-posttest control group design, the research wasconducted in adult male mice (Mus musculus) which were divided into four groups.each consisted of seven mice. One group as a control and the other three wereexposed to sexual abstinence, immobilization stress and the combination of sexualabstinence and immobilization stress in three months period. The investigation wascarried out to the penile total nitrate and nitrite concentration and the histologicalchanges of the middle part of the penile shaft. To know the degree of lesion then thecalculation of the histologic features was done in five view fields of every preparat.The result was compared to control group.In this research, the mean of total nitrate and nitrite decline and the lowest wasfound in the combine intervention groups with significance level p &lt; 0,005. Thecorpus cavernosum in the intervention groups showed multifocal necrosis onendothelial and smooth muscle cells of corpus cavernosum with picnotic nuclei,irregular form and dark colour. Some muscle cells are lysis. These features werefound in three among seven samples in sexual abstinence group, two among sevensamples in immobilization stress group and in all samples of combined interventiongroup.Conclusions can be drawn from this research are that the sexual abstinence,immobilization stress and the combine interventions decline the nitrate and nitriteconcentrations and induce endothelial and smooth muscle cells necrosis of the copuscavernosum.

In vitro investigation of integrin-receptor antagonist-induced vascular toxicity in the mouse

An αVβ3 receptor antagonist (SB-273005) induced unique vascular lesions in the aorta of mice, but not other pharmacologically responsive species. Vascular smooth muscle cell (VSMC) necrosis was observed ∼6h postdose followed by VSMC loss with no evidence of hemorrhage/thrombosis, inflammation or damage to endothelium. Since direct drug-induced vascular toxicity is uncommon, involvement of VSMC–endothelial cell (EC) interactions was hypothesized. In vitro model systems of murine aortic VSMC and EC monocultures and cocultures were established and used to investigate the mechanism of toxicity. Incubation of cultures with SB-273005 within a dose range and timeframe comparable to in vivo studies, showed a concentration-dependent decrease in viability with increases in cytotoxicity for monocultures and VSMC/EC cocultures; however, VSMC monocultures responded at lower doses (were most sensitive) suggesting a direct effect on VSMC which is not mediated or enhanced through EC/VSMC interactions. Further studies revealed increased caspase-9 and caspase-3/7 activation in VSMC beginning as early as 0.5 and 1h following treatment, respectively. These findings suggest SB-273005 causes direct chemical vascular toxicity in murine VSMC which involves apoptosis mediated through the intrinsic (mitochondrial) apoptotic pathway. To our knowledge, this is the first report to provide a link between VSMC apoptosis and treatment with an αVβ3 receptor antagonist.

脳小血管病におけるNeurovascular Unitの障害

Among many conditions causing small vessel diseases, lipohyalinosis is the leading pathology next to microatheroma. Lipohyalinosis affects penetrating arteries distally than microatheroma. Proliferation of smooth muscle cells may occlude the lumen, reducing the blood flow and inducing lacunar infarction. In contrast, fibrinoid necrosis of smooth muscle cells in the media may weaken the vascular constriction, increasing the perfusion pressure in the capillary and damaging the blood brain barrier which can induce white matter lesion. Neurovascular unit (NVU) is a concept that neurons, astrocytes, and vessels function as a unit to support neuronal activity. NVU is involved in the maintenance of synapse, transmitter, energy metabolism, blood-brain barrier, and blood flow. Change in neuronal activity is transmitted to capillaries through NVU, where the information is collected along vessels proximally and regulates blood flow (proximal integration model). CARASIL and CADASIL both affect vascular smooth muscle cells, resulting in vascular dilatation, damaging NVU, and inducing white matter lesion. Occlusion of the affected vessels, causing cerebral ischemia, under these diseases is relatively infrequent. Similarity in pathophysiology between hypertensive arteriolar disease and the familial angiopathy may indicate that injury to NVU may indicate the common pathophysiology of white matter lesions.