Thickness Of Smooth Muscle Layer Research Articles

Chronic OVA allergen challenged Siglec-F deficient mice have increased mucus, remodeling, and epithelial Siglec-F ligands which are up-regulated by IL-4 and IL-13

BackgroundIn this study we examined the role of Siglec-F, a receptor highly expressed on eosinophils, in contributing to mucus expression, airway remodeling, and Siglec-F ligand expression utilizing Siglec-F deficient mice exposed to chronic allergen challenge.MethodsWild type (WT) and Siglec-F deficient mice were sensitized and challenged chronically with OVA for one month. Levels of airway inflammation (eosinophils), Siglec-F ligand expresion and remodeling (mucus, fibrosis, smooth muscle thickness, extracellular matrix protein deposition) were assessed in lung sections by image analysis and immunohistology. Airway hyperreactivity to methacholine was assessed in intubated and ventilated mice.ResultsSiglec-F deficient mice challenged with OVA for one month had significantly increased numbers of BAL and peribronchial eosinophils compared to WT mice which was associated with a significant increase in mucus expression as assessed by the number of periodic acid Schiff positive airway epithelial cells. In addition, OVA challenged Siglec-F deficient mice had significantly increased levels of peribronchial fibrosis (total lung collagen, area of peribronchial trichrome staining), as well as increased numbers of peribronchial TGF-β1+ cells, and increased levels of expression of the extracellular matrix protein fibronectin compared to OVA challenged WT mice. Lung sections immunostained with a Siglec-Fc to detect Siglec-F ligand expression demonstrated higher levels of expression of the Siglec-F ligand in the peribronchial region in OVA challenged Siglec-F deficient mice compared to WT mice. WT and Siglec-F deficient mice challenged intranasally with IL-4 or IL-13 had significantly increased levels of airway epithelial Siglec-F ligand expression, whereas this was not observed in WT or Siglec-F deficient mice challenged with TNF-α. There was a significant increase in the thickness of the peribronchial smooth muscle layer in OVA challenged Siglec-F deficient mice, but this was not associated with significant increased airway hyperreactivity compared to WT mice.ConclusionsOverall, this study demonstrates an important role for Siglec-F in modulating levels of chronic eosinophilic airway inflammation, peribronchial fibrosis, thickness of the smooth muscle layer, mucus expression, fibronectin, and levels of peribronchial Siglec-F ligands suggesting that Siglec-F may normally function to limit levels of chronic eosinophilic inflammation and remodeling. In addition, IL-4 and IL-13 are important regulators of Siglec-F ligand expression by airway epithelium.

Calcium antagonists, diltiazem and nifedipine, protect broilers against low temperature‐induced pulmonary hypertension and pulmonary vascular remodeling

This study was designed to determine whether calcium antagonists, diltiazem and nifedipine, can depress low temperature-induced pulmonary hypertension (PH) in broilers (also known as ascites) and to characterize their efficacy on hemodynamics and pulmonary artery function. Chicks were randomly allocated into six experimental groups and orally administered with vehicle, 5.0 mg/kg body weight (BW)/12 h nifedipine or 15.0 mg/kg BW/12 h diltiazem from 16 to 43 days of age under low temperature. The mean pulmonary arterial pressure (mPAP), the ascites heart index (AHI), the erythrocyte packed cell volume (PCV) and the relative percentage of medial pulmonary artery thickness were examined on days 29, 36 and 43. The data showed that administration of diltiazem protected broilers from low temperature-induced pulmonary hypertension and vascular remodeling. Although nifedipine prevented mPAP from increasing during the early stage, it did not suppress the development of PH during the late stage and did not keep heart rate (HR), PCV, AHI and the thickness of pulmonary small artery smooth muscle layer at the normal levels. Taken together, our results showed that diltiazem can effectively prevent low temperature-induced pulmonary hypertension in broilers with fewer side-effects and may be a potential compound for the prevention of this disease in poultry industry.

Airway Inflammation and Remodeling in Two Mouse Models of Asthma: Comparison of Males and Females

Background: Asthma and especially severe asthma affect women more frequently than men. Since asthma severity correlates with remodeling changes in the lung, a female propensity to remodeling could be expected. We studied whether our previous observation that female mice have more pronounced airway inflammation than males is associated with more pronounced remodeling in two models of chronic allergic asthma. Methods: Male and female BALB/c mice were (1) sensitized and subsequently challenged with ovalbumin (OVA) for 4 weeks, or (2) exposed to house dust mite (HDM) for 5 weeks. In both models, allergic inflammation, remodeling, antigen-specific IgE and methacholine (MCh) responsiveness were assessed. Results: Females had higher antigen-specific serum IgE levels, higher numbers of eosinophils and were more responsive to MCh. In the OVA model, females also had higher levels of Th2 cytokines in lung tissue than males. Both sexes developed similar airway remodeling (smooth muscle layer thickness, collagen III deposition and goblet cell hyperplasia) in the two models. Conclusions: Combining results of an OVA- and a HDM-induced mouse model of allergic airway inflammation, we have shown that more severe allergic inflammation in females is not accompanied with more pronounced airway remodeling.

Toll-Like Receptor-9 Agonist Inhibits Airway Inflammation, Remodeling and Hyperreactivity in Mice Exposed to Chronic Environmental Tobacco Smoke and Allergen

Background: As passive environmental tobacco smoke (ETS) exposure in nonsmokers can increase both asthma symptoms and the frequency of asthma exacerbations, we utilized a mouse model, in which ovalbumin (OVA) + ETS induce significantly increased levels of eosinophilic airway inflammation and remodeling compared to either stimulus alone, to determine whether a Toll-like receptor-9 (TLR-9) agonist could reduce levels of airway inflammation, airway remodeling and airway hyperreactivity (AHR). Methods: Mice treated with or without a TLR-9 agonist were sensitized to OVA and challenged with OVA + ETS for 1 month. AHR to methacholine was assessed in intubated and ventilated mice. Lung Th2 cytokines and TGF-β₁ were measured by ELISA. Lungs were processed for histology and immunohistology to quantify eosinophils, mucus, peribronchial fibrosis and smooth muscle changes using image analysis. Results: Administration of a TLR-9 agonist to mice coexposed to chronic ETS and chronic OVA allergen significantly reduced levels of eosinophilic airway inflammation, mucus production, peribronchial fibrosis, the thickness of the peribronchial smooth muscle layer, and AHR. The reduced airway remodeling in mice treated with the TLR-9 agonist was associated with significantly reduced numbers of peribronchial MBP+ and peribronchial TGF-β₁+ cells, and with significantly reduced levels of lung Th2 cytokines [interleukin-5 and interleukin-13] and TGF-β₁. Conclusion: These studies demonstrate that TLR-9-based therapies inhibit airway inflammation, remodeling and AHR in mice coexposed to ETS and allergen who exhibit enhanced airway inflammation and remodeling.

Food allergy alters jejunal circular muscle contractility and induces local inflammatory cytokine expression in a mouse model

BackgroundWe hypothesized that food allergy causes a state of non-specific jejunal dysmotility. This was tested in a mouse model.MethodsBalb/c mice were epicutaneously sensitized with ovalbumin and challenged with 10 intragastric ovalbumin administrations every second day. Smooth muscle contractility of isolated circular jejunal sections was studied in organ bath with increasing concentrations of carbamylcholine chloride (carbachol). Smooth muscle layer thickness and mast cell protease-1 (MMCP-1) positive cell density were assayed histologically. Serum MMCP-1 and immunoglobulins were quantified by ELISA, and mRNA expressions of IFN-γ, IL-4, IL-6 and TGFβ-1 from jejunal and ileal tissue segments were analyzed with quantitative real-time PCR.ResultsOvalbumin-specific serum IgE correlated with jejunal MMCP-1+ cell density. In the allergic mice, higher concentrations of carbachol were required to reach submaximal muscular stimulation, particularly in preparations derived from mice with diarrhoea. Decreased sensitivity to carbachol was associated with increased expression of IL-4 and IL-6 mRNA in jejunum. Smooth muscle layer thickness, as well as mRNA of IFN-γ and TGF-β1 remained unchanged.ConclusionIn this mouse model of food allergy, we demonstrated a decreased response to a muscarinic agonist, and increased levels of proinflammatory IL-6 and Th2-related IL-4, but not Th1-related IFN-γ mRNAs in jejunum. IgE levels in serum correlated with the number of jejunal MMCP-1+ cells, and predicted diarrhoea. Overall, these changes may reflect a protective mechanism of the gut in food allergy.

Inhibition of Allergen-Induced Airway Remodeling in Smad 3-Deficient Mice

Intracellular signaling pathways that converge on Smad 3 are used by both TGF-beta and activin A, key cytokines implicated in the process of fibrogenesis. To determine the role of Smad 3 in allergen-induced airway remodeling, Smad 3-deficient and wild-type (WT) mice were sensitized to OVA and challenged by repetitive administration of OVA for 1 mo. Increased levels of activin A and increased numbers of peribronchial TGF-beta1(+) cells were detected in WT and Smad 3-deficient mice following repetitive OVA challenge. Smad 3-deficient mice challenged with OVA had significantly less peribronchial fibrosis (total lung collagen content and trichrome staining), reduced thickness of the peribronchial smooth muscle layer, and reduced epithelial mucus production compared with WT mice. As TGF-beta and Smad 3 signaling are hypothesized to mediate differentiation of fibroblasts to myofibroblasts in vivo, we determined the number of peribronchial myofibroblasts (Col-1(+) and alpha-smooth muscle actin(+)) as assessed by double-label immunofluorescence microscopy. Although the number of peribronchial myofibroblasts increased significantly in WT mice following OVA challenge, there was a significant reduction in the number of peribronchial myofibroblasts in OVA-challenged Smad 3-deficient mice. There was no difference in levels of eosinophilic airway inflammation or airway responsiveness in Smad 3-deficient compared with WT mice. These results suggest that Smad 3 signaling is required for allergen-induced airway remodeling, as well as allergen-induced accumulation of myofibroblasts in the airway. However, Smad 3 signaling does not contribute significantly to airway responsiveness.

Bcl-2 Overexpression in the Internal Spermatic Vein of Patients with Varicocele

Varicocele is characterized by dilatation and tortuosity of the internal spermatic vein (ISV). Cross sections of ISV showed marked thickening of smooth muscle layer under microscopy. This study examined Bcl-2 (anti-apoptotic protein) expression in the ISV of patients with varicocele. The study group consisted of eight patients with left varicocele, grade 3. The control group consisted of six volunteers with left indirect inguinal hernia. Using a left inguinal surgical incision, a 1-cm section of ISV was resected from each patient in both groups as specimens for immunoblotting and immunohistochemical staining of Bcl-2. Results were analyzed using Student's t test. Bcl-2 immunoblots from both groups revealed one single band. alpha-tubulin was used as loading control. The average relative intensity of the Bcl-2 was 25.82 +/- 10.53 in the control group and 113.49 +/- 27.49 in the varicocele group. Hematoxylin staining revealed a thickening ISV in the patients with varicocele, predominantly in the muscle layer, which was not found in the control group. Moreover, the intensity of Bcl-2 immunostaining was markedly higher in the study group than in the control group. This study showed Bcl-2 overexpression in the ISV of patients with varicocele. Additional studies are necessary to clarify the molecular mechanisms of varicocele formation and recurrence.

Inhaled corticosteroid prevents the thickening of airway smooth muscle in murine model of chronic asthma

Airway smooth muscle growth contributes to the mechanism of airway hyperresponsiveness (AHR) in asthma. Although current steroid use demonstrates anti-inflammatory activity, there is little reported on the action of corticosteroid on smooth muscle of the asthmatic airway. The present study investigated the effect of inhaled corticosteroid on the thickening of airway smooth muscle in bronchial asthma. We developed a mouse model of airway remodeling including smooth muscle thickening in which ovalbumin (OVA)-sensitized female BALB/c-mice were repeatedly exposed to intranasal OVA administration twice a week for 3 months. Mice were treated intranasally with fluticasone during the OVA challenge. Mice chronically exposed to OVA developed sustained eosinophilic airway inflammation compared with control mice. In addition, the mice chronically exposed to OVA developed features of airway remodeling, including thickening of the peribronchial smooth muscle layer. Intranasal administration of fluticasone inhibited the development of eosinophilic inflammation, and importantly, thickening of the smooth muscle layer. Moreover, intranasal fluticasone treatment reduced the transforming growth factor (TGF)- β1 level in bronchoalveolar lavage fluid and regulated active TGF- β1 signaling with a reduction in the expression of phospho-Smad2/3 and the concomitant up-regulation of Smad7 in lung tissue sections. These results suggest that intranasal administration of fluticasone can modulate the remodeling of airway smooth muscle via regulation of TGF- β1 production and active TGF- β1 signaling.

Reduced peribronchial fibrosis in allergen-challenged MMP-9-deficient mice

Matrix metalloproteinases (MMPs) are a family of extracellular proteases that are responsible for the degradation of the extracellular matrix during tissue remodeling. We have used a mouse model of allergen-induced airway remodeling to determine whether MMP-9 plays a role in airway remodeling. MMP-9-deficient and wild-type (WT) mice were repetitively challenged intranasally with ovalbumin (OVA) antigen to develop features of airway remodeling including peribronchial fibrosis and increased thickness of the peribronchial smooth muscle layer. OVA-challenged MMP-9-deficient mice had less peribronchial fibrosis and total lung collagen compared with OVA-challenged WT mice. There was no reduction in mucus expression, smooth muscle thickness, or airway responsiveness in OVA-challenged MMP-9-deficient compared with OVA-challenged WT mice. OVA-challenged MMP-9-deficient mice had reduced levels of bronchoalveolar lavage (BAL) regulated on activation, normal T cell expressed, and secreted (RANTES), as well as reduced numbers of BAL and peribronchial eosinophils compared with OVA-challenged WT mice. There were no significant difference in levels of BAL eotaxin, thymus- and activation-regulated chemokine (TARC), or macrophage-derived chemokine (MDC) in OVA-challenged WT compared with MMP-9-deficient mice. Overall, this study demonstrates that MMP-9 may play a role in mediating selected aspects of allergen-induced airway remodeling (i.e., modest reduction in levels of peribronchial fibrosis) but does not play a significant role in mucus expression, smooth muscle thickness, or airway responsiveness.

Corticosteroids prevent myofibroblast accumulation and airway remodeling in mice

At present there are conflicting results from studies investigating the role of corticosteroids in inhibiting airway remodeling in asthma. We have used a mouse model to determine whether administration of corticosteroids prevents the development of allergen-induced structural features of airway remodeling. Mice treated with corticosteroids were subjected to repetitive ovalbumin (OVA) challenge for 3 mo, at which time levels of peribronchial fibrosis and the thickness of the peribronchial smooth muscle layer were assessed by immunohistology, levels of transforming growth factor (TGF)-beta1 by ELISA, and the number of alpha-smooth muscle actin+/Col-1+ peribronchial myofibroblasts by immunohistochemistry. Corticosteroids significantly reduced allergen-induced increases in peribronchial collagen deposition and levels of total lung collagen but did not reduce allergen-induced increases in the thickness of the peribronchial smooth muscle layer. Levels of lung TGF-beta1 were significantly reduced in mice treated with systemic corticosteroids, and this was associated with a significant decrease in the number of peribronchial inflammatory cells that expressed TGF-beta1, including eosinophils and mononuclear cells. Corticosteroids also significantly reduced the number of peribronchial myofibroblasts. Overall, these studies demonstrate that administration of corticosteroids significantly reduces levels of allergen-induced peribronchial fibrosis. The reduction in peribronchial fibrosis mediated by corticosteroids is likely to be due to several mechanisms including inhibition of expression of TGF-beta1, a reduction in the number of peribronchial inflammatory cells expressing TGF-beta1 (eosinophils, macrophages), as well as by corticosteroids reducing the accumulation of peribronchial myofibroblasts that contribute to collagen expression.

Smad3‐null mice lack interstitial cells of Cajal in the colonic wall

Transforming growth factor-beta (TGF-beta)/Smad's signalling pathway plays a pivotal role in organogenesis, oncogenesis, inflammation, repair and fibrosis. The aim of this study was to evaluate the morphology of muscle layers and the density and distribution of interstitial cells of Cajal (ICC) in the colon of Smad3 knockout mice. Eighteen Smad3 wild-type mice and 12 null mice were sacrificed at age 4 months and the colons were collected for histology (Haematoxilin-Eosin, Masson thrichrome and Gomori silver staining), morphometry and immunohistochemistry (IHC) analysis. For IHC we used the c-Kit, alpha-smooth muscle actine (alpha-SMA), vimentin, desmin and neuronal cocktail (S-100, NSE, neurofilament 200) antibodies. When sacrificed, 40% of the null mice showed different degrees of colon dilatation when compared with the wild-type. Histological and morphometric evaluation revealed a significant reduction in muscle layer thickness of the colon in all the null mice when compared with the wild-type. Immunohistochemistry evaluation showed a marked reduction, or even absence, of c-Kit immunoreactivity, which identifies ICC, in the colon of all the null mice, compared with the wild-type. Smad3 null mice showed a marked reduction, or even absence, of ICC in the colon together with a concomitant reduction of intestinal smooth muscle layer thickness. This data could account for the colonic dilation observed in approximately 40% of the Smad3 null mice. Alteration of intestinal smooth muscle layers and ICC could also be involved in the resistance of the Smad3 null mice to develop colonic fibrosis.

Morphology of glandular stomach (Ventriculus glandularis) and muscular stomach (Ventriculus muscularis) of the partrigde Rhynchotus rufescens

Twenty adult partridges Rhynchotus rufescens were used for morphologic and histological study. The materials destined to the morphologic study were collected and the lengths of the glandular stomach and of the muscular stomach were measured. For the histological study, fragments of the glandular stomach (gastric proventriculus, Ventriculus glandularis) and of the muscular stomach (gastric ventriculus, Ventriculus muscularis) were stained routinely with periodic acid-Schiff (PAS) and Masson’s trichrome stain. Glandular stomach is prolonged, with a fusiform format toward craniocaudalis and for the left. It presents a mean length of 3.20cm in the females and 3.65cm in the males. Gastric proventriculus is composed by several lobes and glands. The mucosa is formed by a simple cubic epithelium, which is much folded. Muscular stomach has the format of a biconvex lens, with 4.30cm and 4.35cm of mean length for the females and male, respectively. The mucosa is formed by folds lined by columnar cells and the mucus that forms the cuticula. There are crypts in the base of the folds. Closely, there is a lamina propria and a thick smooth muscle layer, which is placed according to the format of the organ. A dense portion of connective tissue constitutes the serosa, mixed by some smooth muscle cells.

Combination of corticosteroid therapy and allergen avoidance reverses allergen-induced airway remodeling in mice

Allergen avoidance and anti-inflammatory therapy are standard therapeutic approaches guidelines advocate to control asthma symptoms. Currently, it is not known whether such strategies reduce airway remodeling. We have therefore used a mouse model of allergen-induced airway remodeling to determine whether allergen avoidance combined with corticosteroid therapy can reverse established airway remodeling. Mice were sensitized to ovalbumin and then repetitively challenged with intranasal ovalbumin for 3 months to develop structural features of airway remodeling including peribronchial fibrosis and increased thickness of the peribronchial smooth muscle layer. At this time point, mice were treated with allergen avoidance, allergen avoidance and corticosteroids, or corticosteroids for 1 month to determine whether either strategy could reverse established airway remodeling. Mice repetitively challenged with ovalbumin developed peribronchial fibrosis (increased total lung collagen and increased peribronchial trichrome staining) as well as increased thickness of the peribronchial smooth muscle layer. Allergen avoidance significantly reduced airway inflammation and mucus expression, slightly reduced peribronchial fibrosis, and had no effect on the thickness of the peribronchial smooth muscle layer. Addition of corticosteroids to allergen avoidance significantly reduced levels of peribronchial fibrosis as well as the thickness of the peribronchial smooth muscle layer. Allergen avoidance reduces airway inflammation and mucus expression but has more limited immediate effects on reducing structural features of established airway remodeling. The combination of allergen avoidance and corticosteroid therapy is effective in reversing established features of airway remodeling including peribronchial fibrosis and the increased thickness of the smooth muscle layer.

Gastroesophageal junction smooth muscle remodeling after endoluminal gastroplication.

Endoluminal gastroplication (ELGP) is an endoscopic mucosal suturing procedure for the treatment of gastroesophageal reflux disease. The antireflux mechanism of the mucosal suture remains poorly understood. The aim of this study is to investigate any morphologic changes in the smooth muscle layer induced by the mucosal sutures placed at the gastroesophageal junction. ELGPs were performed using endoscopic suturing devices with placement of two or three circumferential sutures within 2 cm of the squamocolumnar junction. Eight patients with subsequent symptom resolution underwent endoscopic ultrasound (EUS) to evaluate the muscularis propria layer at the gastroesophageal junction. A swine model was used for EUS and histopathologic correlation study. Six control and 15 ELGP pigs were evaluated with EUS and histological examination of the gastroesophageal junction smooth muscle layer. Focal thickening of the muscularis propria layer near the suture region (2.3 +/- 0.4 mm vs 1.4 +/- 0.3 mm, p < 0.01) was found in eight patients with symptomatic resolution. In ELGP pigs, the smooth muscle layer thickness increased by 2.6 mm near the suture site by EUS. By histology, the total and circular smooth muscle layer thickness increased by 2.1 mm and 1.9 mm, respectively. Focal thickening of smooth muscle layer occurs at the gastroesophageal junction after ELGP in patients with gastroesophageal reflux disease. This finding was reproduced in a swine model and localized hypertrophy was found to be entirely due to an increase in the circular smooth muscle layer.

Effect of Mucosal Sutures on the Muscularis Propria Layer at the Gastroesophageal Junction

Purpose: Endoscopic gastroplications can improve gastroesophageal reflux symptoms in patients, and have been reported to reduce esophageal acid exposure and increase in lower esophageal sphincter pressure in a swine model. The Endoscopic Suturing DeviceTM (ESD, Wilson-Cook, Winston-Salem, NC) is a flexible transoral suturing system available for intraluminal soft tissue apposition. The aim of this study is to investigate the effect of mucosal sutures created using ESD on the muscularis propria layer at the gastroesophageal junction (GEJ) in a swine model. Methods: Female domestic pigs weighing 30 kg were used as control (n=6) and study (n=6) animals. An upper endoscopy with endoscopic ultrasound (EGD/EUS) was performed in all animals at baseline. The appearance and thickness of the muscularis propria layer at the GEJ was imaged and measured endosonographically. In each study animal, two gastroplications were created using ESD at the squamo-columnar junction. EGD/EUS was repeated at 3 weeks after the suturing procedure and then the animal was sacrifice. The distal esophagus and proximal stomach were fixed in formalin while the intraluminal diameter were kept constant for all specimens. The thickness of the muscularis propria layer was measured histologically and correlated with EUS findings. Ultra-structural changes were evaluated with electron microscopy (EM). Results: Mucosal sutures induced a focal increase in the muscularis propria layer thickness at the GEJ near the suture site. The baseline thickness measured 1.12 ± 0.14 mm by EUS, 3 weeks after the procedure the thickness increased to 3.84 ± 0.69 mm (p<0.01) near the suture site. The length of the focal increase in thickness measured 13.2 ± 4.9 mm by EUS. Histologic examination confirmed this localized increase in thickness of the muscularis propria layer near the mucosal suture when compared to the control, 8.0 ± 1.9 mm vs. 5.7 ± 1.6 mm (p=0.03). The increase in smooth muscle cell mass was due entirely to hypertrophy of the circular smooth muscle layer, 6.2 ± 1.7 mm vs. 4.2 ± 1.6 (p=0.04). The thickness of the longitudinal smooth muscle layer remained unchanged. Transmission EM of the smooth muscle cells revealed cellular and nuclear changes as well as intra-cellular collagen deposition. Conclusions: In a swine model, mucosal sutures placed by the Endoscopic Suturing Device led to focal hypertrophy of the muscularis propria layer at the gastroesophageal junction.

Inhibition of airway remodeling in IL-5-deficient mice.

To determine the role of IL-5 in airway remodeling, IL-5-deficient and WT mice were sensitized to OVA and challenged by repetitive administration of OVA for 3 months. IL-5-deficient mice had significantly less peribronchial fibrosis (total lung collagen content, peribronchial collagens III and V) and significantly less peribronchial smooth muscle (thickness of peribronchial smooth muscle layer, alpha-smooth muscle actin immunostaining) compared with WT mice challenged with OVA. WT mice had a significant increase in the number of peribronchial cells staining positive for major basic protein and TGF-beta. In contrast, IL-5-deficient mice had a significant reduction in the number of peribronchial cells staining positive for major basic protein, which was paralleled by a similar reduction in the number of cells staining positive for TGF-beta, suggesting that eosinophils are a significant source of TGF-beta in the remodeled airway. OVA challenge induced significantly higher levels of airway epithelial alphaVbeta6 integrin expression, as well as significantly higher levels of bioactive lung TGF-beta in WT compared with IL-5-deficient mice. Increased airway epithelial expression of alphaVbeta6 integrin may contribute to the increased activation of latent TGF-beta. These results suggest an important role for IL-5, eosinophils, alphaVbeta6, and TGF-beta in airway remodeling.

Bladder smooth muscle cell phenotypic changes and implication of expression of contractile proteins (especially caldesmon) in rats after partial outlet obstruction.

The purpose of the present study was to investigate morphological changes in bladder smooth muscle of rats with partial outlet obstruction. We investigated smooth muscle cell phenotypic changes and implication of synthetic phenotype in contractility decrease and bladder compliance after bladder outlet obstruction. Partial bladder outlet obstruction was introduced in female rats. Bladder were removed at 1, 3, 6, 10 and 20 weeks after the obstruction. Temporal pattern of changes in bladder mass, light microscopic pathogenesis and phenotypic expression of the bladder smooth muscle cells in the electron micrographs were investigated. Expression of contractile protein was also investigated by the immunoblotting method. Marked increase in bladder mass with marked thickening of smooth muscle layer was observed at 1 week after obstruction. The ratio of myocytes exhibiting contractile and synthetic phenotypes was almost constant until 6 weeks after the obstruction, but thereafter, synthetic phenotypes gradually increased and the ratio (synthetic/contractile phenotype) was 1.5-fold at 20 weeks after the obstruction. Caldesmon was most markedly expressed after the obstruction among contractile proteins examined by the immunoblotting method. Phenotypic changes were confirmed in bladder smooth muscle, and the decrease of the ratio of contractile phenotype was observed after long-term obstruction of the bladder outlet. Among the contractile proteins in the bladder smooth muscle cell, caldesmon was considered a reliable marker for predicting the pathogenetic conditions of the bladder.

Cholinergic pathways modulate experimental dinitrobenzene sulfonic acid colitis in rats

Recent studies have suggested that neuroimmune interactions modulate intestinal mucosal immune responses. In the current study, we examined the role of cholinergic pathways in modulating the severity of acute dinitrobenzene sulfonic acid colitis, using pharmacological agents to suppress acetylcholinesterase in Sprague–Dawley rats, and evaluating the colitis in the cholinergic hyperresponsive Flinder's sensitive line rats and their control counterparts, the Flinder's resistant line. Colitis was induced by intrarectal dinitrobenzene sulfonic acid (80 mg ml −1 in 50% ethanol); controls received intrarectal saline. Sprague–Dawley rats received an acetylcholinesterase inhibitor, physostigmine (50 μg kg −1 s.c.) or neostigmine (50 μg kg −1 s.c.), 30 min prior to intrarectal dinitrobenzene sulfonic acid; controls received saline vehicle. On day 5, the macroscopic damage score, myeloperoxidase activity (an estimate of granulocyte infiltration) and smooth muscle thickness were evaluated in the inflamed colonic segment. Significant increases in macroscopic damage score and colonic smooth muscle thickness were observed in Sprague–Dawley and Flinder's Resistant Line rats on day 5 following intrarectal dinitrobenzene sulfonic acid compared to saline controls. Increased myeloperoxidase activity was also observed in dinitrobenzene sulfonic acid-treated Sprague–Dawley rats and Flinder's Resistant Line rats. In contrast, Flinder's Sensitive Line rats failed to demonstrate a significant rise in macroscopic damage, smooth muscle layer thickness, or myeloperoxidase activity on day 5 following intrarectal dinitrobenzene sulfonic acid when compared to saline-treated Flinder's Sensitive Line controls. Neostigmine and physostigmine treatment prior to intrarectal dinitrobenzene sulfonic acid significantly attenuated macroscopic damage score, myeloperoxidase activity and smooth muscle thickness on day 5 compared to colitic Sprague–Dawley controls. Significantly greater reductions in myeloperoxidase activity were observed with physostigmine vs. neostigmine pretreatment. These data suggest that cholinergic pathways modulate the acute colonic inflammatory response associated with the dinitrobenzene sulfonic acid model, with central pathways exerting a greater protective effect relative to peripheral pathways. Further studies are required to determine the contributions of sites in the nervous system and neuro-effector junctions.

Morphological aspects of the spermatic cord of mice (Mus musculus)

A histological study of the morphological aspects of 33 spermatic cord pairs of adult mice (Mus musculus) showed that its their components were ensheated by a thin mesothelium capsule in 3 pairs. Under this capsule, completely surrounding the cord, there was a dense layer of adipose tissue. Its components were surrounded by loose connective tissue with a predominance of collagen fibers among reticular and elastic fibers. The testicular artery varied in diameter and was involved by the testicular veins, consisting of an inner layer formed by endothelium and an inner limiting elastic membrane, a middle layer formed by a thick smooth muscle layer supported by a network of reticular fibers, and an outer layer consisting of dense connective tissue close to the intervascular connective tissue and the adventitia layers of the veins. The testicular veins form the pampiniform plexus which partially surrounds the artery, presenting wide and irregular lumens, thin walls consisting almost exclusively of endothelium, with no valves and intimately related to the testicular artery. The vas deferens is located at the periphery of the subcapsular adipose tissue which partially surrounds it and is accompanied by arterioles, venules, lymphatic vessels and nerves. The cast of the segment of testicular artery obtained with Neoprene 450 latex in 60 molds exhibited a sinuous trajectory and the length (cm): was mean, maximum and minimum, 1.35. 1.80 and 0.80 on the right and 1.32. 1.85 and 0.70 on the left, respectively. These values showed no significance at 5%.

Beyond our pages

Beyond our pages