Rat Peritoneum Research Articles

Bacterial Cellulose Membrane Experimentally Implanted in the Peritoneum of Wistar Rats—Inflammatory Immunoreactivity and Oxidative Stress

Bacterial cellulose (BC) has been used for various applications; however, studies investigating the immunohistochemical characteristics of the inflammatory and scarring component in BC implanted in the peritoneum in vivo have not yet been fully described. This study aimed to evaluate the systemic and organic safety of BC through oxidative stress, blood, and serum biochemical markers, as well as the late inflammatory response in rats, using histopathology and immunohistochemistry. Forty-three rats (26 males; 17 females) received BC in the peritoneal cavity (implanted group—IG), while twenty-seven rats (12 males; 15 females) served as the control (sham group—SG). Sixty days after surgery, oxidative stress in tissues, blood biochemical markers, and histopathological and immunohistochemical analyses for lymphocytes, macrophages, collagen, and vascular response around the BC were assessed. Only one oxidative stress marker, glutathione peroxidase, was elevated in the liver of IG rats. Creatine kinase MB and lactate dehydrogenase levels were significantly lower in IG animals. Histopathological analysis showed granulomatous inflammation in 93% of IG rats, with 74% of mild intensity. Immunohistochemistry revealed a significant macrophage presence (F4/80), with CD3, CD20, and F4/80 markers indicating differences favoring macrophages. In conclusion, BC implantation in the peritoneum induces a foreign body granulomatous response with prominent macrophage presence (F4/80). Type I and III collagen were observed around the membrane, and vascularization was intense 60 days post-implantation. From a biochemical and oxidative stress perspective, BC seems to be a safe material to be used in the peritoneal cavity.

MORPHOLOGICAL SUBSTANTIATION OF THE EFFECTIVENESS OF PHOTODYNAMIC THERAPY IN CASE OF WIDESPREAD PERITONITIS IN AN EXPERIMENT

The article presents the results of experimental studies on the effects on the parietal and visceral peritoneum of intact animals and with simulated widespread peritonitis in white mongrel rats weighing 140 180 g. It was found that methylene blue at a concentration of 0.05% in intact animals at exposure of 5 minutes causes desquamation and small foci of necrosis of mesothelial cells, and in peritonitis against the background of photodynamic therapy has a beneficial effect on reparative processes due to the formation of singlet oxygen. The histological picture of the peritoneum in rats after abdominal sanitation by PDT at all stages of the study was qualitatively better than that of the representatives of the group during abdominal sanitation with 0.02% chlorhexidine solution. Based on the results of morphological studies, the authors recommend that the developed method of photodynamic sanitation of the abdominal cavity be introduced into clinical practice.

Original Empirical Research Protective Effects of Succinic Acid upon Exposure to the Low-Frequency Alternating Magnetic Field Determined in the Experiment

Introduction. The need to simulate the oxidative stress by an experiment of exposure to the low-frequency alternating magnetic field is induced by the persistent increase of the electromagnetic load on the endothermic organisms caused by the annual deterioration of the electromagnetic state of the environment. The low-frequency alternating magnetic field starts a chain of biochemical reactions in the laboratory animals, which alter the homeostasis against the increased intensity of free-radical oxidation (peroxidation) of biomembrane lipids. The preparations containing succinic acid have the antioxidant, antihypoxant, actoprotective and stress-protective effects, tested through various kind of modelling, however, the absence of data on the efficacy of succinic acid under the exposure to the alternating magnetic field has become the reason for the present experiment. The aim of the research is to determine the protective effects of succinic acid upon exposure of the laboratory rats to the low-frequency alternating magnetic field.Materials and Methods. The objects of the research were 90 white outbred male rats weighing 200–250 g, divided into three groups: group 1 — intact, the animals were in standard vivarium conditions and were not exposed to any effect; group 2 — control, the rats were exposed to the low frequency alternating magnetic field (LF-AMF) for 21 days daily per 3 hours, preceded by daily intraperitoneal administration to animals of the 0.9% sodium chloride solution at a dose of 1 ml / kg straight before them being exposed to LF-AMF; group 3 — experimental, the rats were daily intraperitoneally administered the succinic acid at a dose of 100 mg / kg (1 ml / kg) for 21 days prior to being exposed to LF-AMF. The exposure to the low-frequency alternating magnetic field was created by the Helmholtz coils (of diameter 1 m) powered by the alternating current source with a frequency of 50 Hz, with a magnetic field induction of 0.4 mT, whereas the cages with animals were placed in the centre of the device. The actoprotective effect of succinic acid was checked on the 7th, 14th and 21st days from the beginning of the experiment by duration of swimming of rats in water. The antioxidant effect — by concentration of diene conjugates, lipid hydroperoxides, malondialdehyde, ceruloplasmin, vitamin E in the blood plasma of rats measured according to the commonly accepted methods. The stress-protective effect was determined by the masses of the adrenal glands, thymus gland, spleen and the number of erosive defects on the suRussian Federationace of the gastric mucosa.Results. The experimental data has confirmed the actoprotective effect of succinic acid — the duration of swimming of the rats in the experimental group increased by 25–37% compared to the control one. The antioxidant effect of succinic acid under magnetic induction has been manifested in a decreased concentration of lipid peroxidation products against increased level of ceruloplasmin in the blood of rats in the experimental group compared to the animals in the control group. Administration of the succinic acid into the peritoneum of rats in the experimental group under exposure to the low frequency alternating magnetic field has prevented involution of the thymus gland by 45% (7th day), 56% (14th day), 71% (21th day) and the spleen by 52%, 58% and 66% respectively, alongside, the number of erosive and ulcerative defects on the suRussian Federationace of the gastric mucosa has decreased by 2.5–4 times compared to the animals in the control group.Discussion and Conclusion. The protective effects of succinic acid upon exposure to the low-frequency alternating magnetic field have been confirmed that include the stress-protective, actoprotective and antioxidant effects of the exogenous succinate. The ability of succinic acid to prevent the negative changes in the internal organs caused by the magnetic loads is proved by the statistically significant excess of the mass coefficients of the thymus gland and spleen in the experimental group, compared to the control one, along with the fewer erosive defects on the suRussian Federationace of the gastric mucosa. Succinic acid reduces the intensity of lipid peroxidation processes upon the magnetic exposure due to reducing the concentration of lipid peroxidation products and increasing the level of ceruloplasmin in the blood of animals.

X‐Ray Visualized Sensors for Peritoneal Dialysis Catheter Infection

AbstractPeritonitis is a common complication for patients with end‐stage renal disease undergoing peritoneal dialysis (PD) and is a direct cause or contributor in >15% deaths in PD patients. Since early detection is key to treatment, patients and their care teams need rapid, on‐site diagnostics. A hydrogel‐based peritoneal fluid pH sensor attached to a peritoneal dialysis catheter is developed to measure local acidosis indicative of peritoneal infections for early detection and monitoring of infections using X‐ray imaging. The sensor comprises a polyacrylic acid hydrogel with embedded radiopaque markers enclosed in a polymer casing; contraction of the hydrogel in response to acidic pH is evident from the radiographically measured marker position. The sensor has a pH 4–8 response range; between pH 6.5 and 7.5 it responds linearly with a slope of 14% pH 7 length per pH unit, and about 1% length precision. The sensor is attached to a catheter and implanted in a rat peritoneum. Results in awake rats show a rapid pH drop during infection not observed in systemic C‐reactive proteins (CRP) levels nor in the uninfected control animal, with negligible drift over 2 weeks. To our knowledge, this is the first report of an in vivo chemically responsive hydrogel sensor.

Novel silk protein/hyaluronic acid hydrogel loaded with azithromycin as an immunomodulatory barrier to prevent postoperative adhesions

Peritoneal adhesions, a common postoperative complication of laparotomy, are still treated with physical barriers, but their efficacy and ease of use are controversial. In this paper, we developed a wound microenvironment-responsive hydrogel composed of Antheraea pernyi silk protein (ASF) from wild cocoons and tyramine-modified hyaluronic acid (HA-Ph) loaded with azithromycin (AZI), glucose oxidase (GOX), and horseradish peroxidase (HRP). In addition, GOX-catalyzed oxygen production enhanced the antibacterial ability of the hydrogel. Moreover, the drug-loaded hydrogel increased macrophage CD206 expression while decreasing IL-6 and TNF-α expression. More importantly, the retarding effect of this novel hydrogel system on AZI almost eliminated the appearance of postoperative adhesions in rats. It was also found that the novel hydrogel enhanced the modulation of the TLR-4/Myd88/NF-κB pathway and TGF-β/Smad2/3 pathway by azithromycin in the locally damaged peritoneum of rats, which accelerated the remodeling of damaged tissues and dramatically reduced the deposition of collagen. Therefore, spraying the novel drug-loaded hydrogel on postoperative abdominal wounds can effectively inhibit the formation of postoperative adhesions.

Antidiabetic effect of Borassus flabellifer L. extracts on streptozotocin-induced diabetic rats

Background: Around the world, the number of people with diabetes is rising at an alarming rate, and experts have been using ancient drugs that are mostly made from plants as treatments.This study aimed to see if Borassus flabellifer L. palm sprout ethanolic extracts could help treat diabetes in rats made diabetic by streptozotocin (STZ). Methods: STZ (45 mg/kg bw) was injected once into the peritoneum of male albino Wistar rats. This caused them to get diabetes. For 60 days, intragastric intubation was used to give diabetic rats B. flabellifer palm sprout ethanolic extracts (400 mg/kg bw) and glibenclamide (1 mg/kg bw). Results: As a result, the rats lost a lot of weight, their blood sugar and glycosylated hemoglobin levels went up, and their total hemoglobin (Hb) levels went down. Furthermore, glucose-6-phosphatase and fructose-1,6-bis phosphatase were higher in rats made diabetic by STZ, while hexokinase and glycogen levels were lower. When diabetic rats were given ethanolic extracts of B. flabellifer palm sprouts and glibenclamide, their blood glucose and glycosylated Hb levels went down very well, and their Hb levels went up. Changes in how enzymes that break down carbohydrates and liver glycogen work were greatly improved. Conclusion: The results of the ethanolic extracts of B. flabellifer palm sprouts were similar to those of the standard drug glibenclamide. The results of this study back up the traditional use of plant extracts to treat diabetes.

The expression of matrix metalloproteinase-12 in the peritoneum of rats with continuous peritoneal dialysis.

Peritoneal dialysis (PD) is an important alternative treatment for end-stage renal disease. Continuous exposure to non-physiological fluids during PD is associated with pathological responses, such as sustained microinflammation, leading to tissue fibrosis and angiogenesis. However, the effect of PD fluid on submesothelial cells has not yet been investigated in detail. We investigated the association between macrophages and the expression of matrix metalloproteinase-12 (MMP-12), an elastin proteinase secreted by macrophages, in the peritoneal tissue of rats undergoing continuous PD. Morphological data revealed that the submesothelial layer of the peritoneum in PD model rats was markedly thickened, with fibrosis and angiogenesis. In the fibrillization area, elastin was disorganized and fragmented, and macrophages accumulated, which tended to have M2 characteristics. The expression of MMP-12 was enhanced by continuous exposure to PD fluid, suggesting that MMP-12 expression may be involved in PD fluid-induced peritoneal damage. The results of this study may lead to a better understanding of the mechanisms underlying fibrosis in PD.

Blockade of prostaglandin E2 receptor 4 ameliorates peritoneal dialysis-associated peritoneal fibrosis.

Inflammatory responses in the peritoneum contribute to peritoneal dialysis (PD)-associated peritoneal fibrosis. Results of our previous study showed that increased microsomal prostaglandin E synthase-1-mediated production of prostaglandin E2 (PGE2) contributed to peritoneal fibrosis. However, the role of its downstream receptor in the progression of peritoneal fibrosis has not been established. Here, we examined the role of PGE2 receptor 4 (EP4) in the development of peritoneal fibrosis. EP4 was significantly upregulated in peritoneal tissues of PD patients with ultrafiltration failure, along with the presence of an enhanced inflammatory response. In vitro experiments showed that exposure to high glucose concentrations enhanced EP4 expression in rat peritoneal mesothelial cells (RPMCs). High-glucose-induced expression of inflammatory cytokines (monocyte chemoattractant protein-1, tumour necrosis factor α, and interleukin 1β) was significantly reduced in RPMCs treated with ONO-AE3-208, an EP4 receptor antagonist. ONO-AE3-208 also significantly decreased the expression of extracellular matrix proteins induced by high glucose concentrations. Furthermore, ONO-AE3-208 blunted activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome and phosphorylation of nuclear factor kappa B (NF-κB) (p-p65). To further investigate the functional role of EP4, ONO-AE3-208 was administrated for 4weeks in a rat model of PD, the results of which showed that ONO-AE3-208 inhibited peritoneal fibrosis and improved peritoneal dysfunction. Additionally, inflammatory cytokines in the peritoneum of PD rats treated with ONO-AE3-208 were downregulated, in line with inhibition of the NLRP3 inflammasome and NF-κB phosphorylation. In conclusion, an EP4 antagonist reduced the development of peritoneal fibrosis, possibly by suppressing NLRP3 inflammasome- and p-p65-mediated inflammatory responses. Our findings suggest that an EP4 antagonist may be therapeutically beneficial for PD-associated peritoneal fibrosis.

Crocin ameliorates peritoneal fibrosis in rat induced by peritoneal dialysis via Wnt5a/β-Catenin pathway

Peritoneal dialysis is used in the treatment of patients with kidney diseases. Long-term peritoneal dialysis could result in peritoneal fibrosis and recurrent peritonitis, thus leading to failure of ultrafiltration. Crocin is a bioactive carotenoid and isolated from stigma of Crocus sativus, and ameliorates pulmonary and myocardial fibrosis. The role of crocin in peritoneal fibrosis was assessed. Firstly, rats model with peritoneal dialysis was treated with 4.25% peritoneal dialysate. Results showed that injection with peritoneal dialysate induced obvious hyperplasia and increased thickness in peritoneum structure. Rats with peritoneal dialysis were injected with increasing concentrations of crocin at 10, 20, or 40 mg/kg. Crocin ameliorated the pathological changes in the peritoneum of peritoneal dialysate-induced rats. Secondly, crocin attenuated peritoneal dialysate-induced decrease of E-cadherin, increase of fibronectin, α-smooth muscle actin (α-SMA), and collagen I. Moreover, crocin enhanced ultrafiltration volume and reduced glucose transport in rats model with peritoneal dialysis. Thirdly, crocin also reduced levels of Interleukin (IL)-1β, Tumor Necrosis Factor-α (TNF –α), and IL-6 in peritoneal tissues of rats model with peritoneal dialysis. Lastly, protein expression of Wnt5a and β-Catenin in rats model with peritoneal dialysis were also downregulated by crocin. In conclusion, crocin exerted anti-inflammatory and anti-fibrotic effects on rats model with peritoneal dialysis through inactivation of Wnt5a/β-Catenin pathway.

ХАРАКТЕРИСТИКА ИЗМЕНЕНИЙ В ОРГАНИЗМЕ КРЫС С ОСТРЫМ ЭКСПЕРИМЕНТАЛЬНЫМ ПЕРИТОНИТОМ

Background. The lack of decrease in lethality with diffuse peritonitis may be due to a result of the incomplete understanding of the mechanisms of its development. The aim of the research was to study the changes in rats with acute experimental peritonitis. Material and methods. The experiments were carried out on male rats (n=74) divided into 2 series and intraperitoneally injected with: series 1 (control) – 0.9% sodium chloride, series 2 (experimental peritonitis, EP) – 15% fecal suspension, 0.6 ml/100 g. In each group the research was performed in half a day (n=6), 1 day (n=6) and 3 days (n=6) after peritonitis modeling along with the assessment of rats lethality (n=19). The signs of intoxication, the reaction of blood and peritoneal leukocytes, the nitrite/nitrates level and parameters of prooxidant-antioxidant status, the degree of damage to vascular endothelium and peritoneum in rats with peritonitis were analyzed. Results. The decrease in motor activity and muscular strength, the development of fever and tachypnea, leukocytosis in the blood and peritoneal fluid with the increase in quantity of neutrophils and macrophages, appearance of metamyelocytes and myelocytes with the decrease in the percentage of peritoneal formazan-positive neutrophils, reduction in lymphocytes quantity and the lack of eosinophils, rise in concentrations of nitrites/nitrates and lipid peroxidation product – malondialdehyde along with the decrease in the level of antioxidant – reduced glutathione, increase in the quantity of circulating endothelial cells in blood and significant changes of the peritoneum structure were revealed in rats with peritonitis. Conclusions. The research of changes in rats with acute experimental peritonitis has revealed the signs of marked intoxication, changes in the leukocyte differential count of blood and peritoneal fluid in type of neutrophilicmacrophageal leukocytosis with a hyperregenerative shift of leukocyte differential count to the left and impaired ability of peritoneal neutrophils to phagocytosis along with lymphopenia and aneosinophilia, the increase in the level of nitrites/nitrates, development of oxidative stress, lesion of vascular endothelium and significant changes of peritoneum structure.

MiR-122-5p promotes peritoneal fibrosis in a rat model of peritoneal dialysis by targeting Smad5 to activate Wnt/β-catenin pathway

Peritoneal fibrosis (PF) is the main reason leading to declining efficiency and ultrafiltration failure of peritoneum, which restricts the application of peritoneal dialysis (PD). We aimed to investigate the effects and mechanisms of miR-122-5p on the PF. Sprague-Dawley (SD) rats were infused with glucose-based standard PD fluid to establish PF model. HE staining was performed to evaluate the extent of PF. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and fluorescence in situ hybridization (FISH) were performed to measure the expression level of miR-122-5p. Western blot was used to test the expression of transforming growth factor (TGF)-β1, platelet-derived growth factor (PDGF)-A, Fibronectin 1 (FN1), extracellular matrix protein 1 (ECM1), Smad5, α-smooth muscle actin (SMA), collagen type 1(COL-1), Vimentin, E-Cadherin, Wnt1, β-catenin, p-β-catenin, c-Myc, c-Jun, and Cyclin D1. Immunohistochemistry (IHC) staining was used to detect type I collagen alpha 1 (Col1α1), α-SMA, and E-Cadherin expression. We found PF was glucose concentration-dependently enhanced in peritoneum of PD rat. The PD rats showed increased miR-122-5p and decreased Smad5 expression. MiR-122-5p silencing improved PF and epithelial–mesenchymal transition (EMT) process in PD rats. MiR-122-5p silencing attenuated the activity of the Wnt/β-catenin signaling pathway. Importantly, dual-luciferase reporter assay showed Smad5 was a target gene of miR-122-5p. Smad5 overexpression significantly reversed the increases of PF and EMT progression induced by miR-122-5p overexpression. Moreover, miR-122-5p mimic activated Wnt/β-catenin activity, which was blocked by Smad5 overexpression. Overall, present results demonstrated that miR-122-5p overexpression showed a deterioration effect on PD-related PF by targeting Smad5 to activate Wnt/β-catenin pathway.

Macroscopic and histopathological features of acute peritoneal infection in diabetic and euglycemic Wistar rats.

Impact of the secondary peritoneal infections on the peritoneal morphology in diabetic population remains unclear. To study the histopathological changes of the peritoneum due to secondary bacterial peritonitis in diabetic rats in compari-son to the normoglycemic animals. 13 adult male Wistar rats were divided into 2 groups: control (n = 3) and experimental (n = 10). The latter was subdivided into non-diabetic (n = 5) and diabetic (n = 5). T1DM and peritonitis were induced through the single intraperitoneal injec-tion of Streptozotocin (60 mg/kg) and intraperitoneal injection of 2 ml of the faecal matter, respectively. Macroscopic findings of diabetic rat peritoneum included significant accumulation of the exudate in the peritoneal cavity and presence of intraintestinal adhesions and abscesses. Morphology of the peritonium presented with diffuse, profound degenerative and inflammatory lesions involving the subjacent tissues. In contrast, the underlying muscular layer of the non-diabetic rats remained intact. Natural course of the peritoneal infection in diabetic rats (48 hours) is characterised by diffuse severe peritonitis with inter-intestinal abscess formation and more profound subadjacent tissue involvement in comparison with non-diabetic rats.

The Study of Efficiency of the Approach to Prevent the Adhesions in the Abdominal Cavity of Rats

Adhesions in rat abdominal cavity were studied after laparotomy and subsequent single intraperitoneal injection of 2 ml of 5% aqueous solution of oxidized dextran (OD) with a molecular weight of 40 kDa (oxidation degree 10%). On days 7 and 21 after laparotomy, the number of adhesions in OD-treated rats was lower by 7.5 and 4 times than in animals not receiving OD. The number of neutrophils in adhesions on day 21 was manyfold lower in OD-treated rats. In 7 and 21 days after laparotomy, the number of fibroblasts in the adhesions of rats receiving and not receiving OD was similar, but 2-fold higher than in the peritoneum of non-operated rats. The content of collagen in adhesions on day 21 after laparotomy in OD-treated rats was 10-fold lower than in animals no receiving OD.

COMPARATIVE STUDY OF HISTOLOGICAL AND HISTOCHEMICAL PROPERTIES OF PERITONEAL MAST CELLS OF ALBINO RAT USING TWO TYPES OF FIXATIVES

Objectives: To make a comparative study of histological and histochemical properties of peritoneal mast cells in albino rat using neutral buffered formalin and formal alcohol as fixatives.
 Methods: The stretch preparation from Albino rat peritoneum was made on chemically clean glass slides and immediately placed into the fixatives.
 Results: With toluidine blue (pH 4.4), the mast cells stained deep purple and similar reaction was obtained with toluidine blue at pH 2. These staining reactions indicate the presence of substantial amount of heparin trisulfate, small amount of heparin monosulfate, and neutral mucopolysaccharide.
 Conclusion: Heparin trisulfate is an active form of heparin and is the main constituent of the mast cell granules of the albino rat.

Newly designed Protein Transduction Domain (PTD)-mediated BMP-7 is a potential therapeutic for peritoneal fibrosis.

While the bone morphogenetic protein‐7 (BMP‐7) is a well‐known therapeutic growth factor reverting many fibrotic diseases, including peritoneal fibrosis by peritoneal dialysis (PD), soluble growth factors are largely limited in clinical applications owing to their short half‐life in clinical settings. Recently, we developed a novel drug delivery model using protein transduction domains (PTD) overcoming limitation of soluble recombinant proteins, including bone morphogenetic protein‐7 (BMP‐7). This study aims at evaluating the therapeutic effects of PTD‐BMP‐7 consisted of PTD and full‐length BMP‐7 on epithelial‐mesenchymal transition (EMT)‐related fibrosis. Human peritoneal mesothelial cells (HPMCs) were then treated with TGF‐β1 or TGF‐β1 + PTD‐BMP‐7. Peritoneal dialysis (PD) catheters were inserted into Sprague‐Dawley rats, and these rats were infused intra‐peritoneally with saline, peritoneal dialysis fluid (PDF) or PDF + PTD‐BMP‐7. In vitro, TGF‐β1 treatment significantly increased fibronectin, type I collagen, α‐SMA and Snail expression, while reducing E‐cadherin expression in HPMCs (P < .001). PTD‐BMP‐7 treatment ameliorated TGF‐β1‐induced fibronectin, type I collagen, α‐SMA and Snail expression, and restored E‐cadherin expression in HPMCs (P < .001). In vivo, the expressions of EMT‐related molecules and the thickness of the sub‐mesothelial layer were significantly increased in the peritoneum of rats treated with PDF, and these changes were significantly abrogated by the intra‐peritoneal administration of PTD‐BMP‐7. PTD‐BMP‐7 treatment significantly inhibited the progression of established PD fibrosis. These findings suggest that PTD‐BMP‐7, as a prodrug of BMP‐7, can be an effective therapeutic agent for peritoneal fibrosis in PD patients.

E-cigarette, or Vaping, Associated Lung and Hepatic Injury.

E-cigarette, or Vaping, Associated Lung and Hepatic Injury.

Sodium aescinate significantly suppress postoperative peritoneal adhesion by inhibiting the RhoA/ROCK signaling pathway

BackgroundAlthough mechanical barriers and modern surgical techniques have been developed to prevent postoperative adhesion formation, high incidence of adhesions still represents an important challenge in abdominal surgery. So far, there has been no available therapeutic drug in clinical practice. PurposeIn this study, we explored the efficacy of sodium aescinate (AESS) treatment against postoperative peritoneal adhesions, the potential molecular mechanism was also investigated. Study design and methodsSixty male Sprague-Dawley rats were randomly divided into 6 groups for the study: the blank, vehicle, positive control and three AESS administration groups (0.5, 1 and 2 mg/kg/d, intravenous administration for 7 days). Adhesions were induced by discretely ligating peritoneal sidewall. An IL-1β-induced HMrSV5 cell model was also performed to explore possible functional mechanism. ResultsThe results indicated that the incidence and severity of peritoneal adhesions were significantly lower in the AESS-treated groups than that in the vehicle and positive control group. AESS-treated groups showed that the secretion, activity, and expression of tPA in rat peritoneum were notably increased. The FIB levels in rat plasma were decreased. The immunohistochemical staining analysis demonstrated that collagen I and α-SMA deposition were significantly attenuated in AESS-treated peritoneal tissues. Besides, we found that AESS treatment reduced the protein levels of p-MYPT1. To further explore the mechanisms of AESS, both activator and inhibitors of RhoA/ROCK pathway were employed in this study. It was found that AESS-induced up-regulation of tPA was reversed by activator of ROCK, but the effects of ROCK inhibitors were consistent with AESS. ConclusionTaken together, the findings of in vivo and in vitro experiments proved that AESS could significantly suppress postoperative peritoneal adhesion formation through inhibiting the RhoA/ROCK signaling pathway. Our researches provide important pharmacological basis for AESS development as a potential therapeutic agent on peritoneal adhesions.

The Ethanol Extract of Avocado (Persea americana Mill. (Lauraceae)) Seeds Successfully Induces Implant Regression and Restores Ovarian Dynamic in a Rat Model of Endometriosis.

Endometriosis is an estrogen-dependent disease with conventional therapies which do not have desirable effectiveness and possess many side effects. Scientific evidences suggest that medicinal plants with antioxidant, anti-inflammatory, and/or antiproliferative properties are potential alternatives for the treatment of endometriosis. The ethanol extract of Persea americana Mill. (Lauraceae) seeds was found exhibiting antiproliferative properties in vitro and in vivo. This study therefore is aimed at investigating the effects of such an extract on an experimental model of endometriosis. Endometriosis was induced by grafting uterine fragments onto the peritoneum of female Wistar rats. After checking the success of the transplantation surgery, animals with endometriosis were orally treated with the ethanol extract of P. americana seeds at the doses of 12.5, 25, and 50 mg/kg. The positive control was treated with letrozole (10 mg/kg) while the negative control received the vehicle. Treatments lasted 7 days and animals were sacrificed thereafter. Endometrial implant volume was determined. Estradiol and progesterone levels were measured in serum samples and endometriosis lesions. The oxidative status of endometriosis lesions was evaluated. Histological analysis of endometriosis lesions, uterus, and ovaries was also performed. Results showed that the ethanol extract of P. americana seeds decreased endometrial implant volume (p < 0.001) and serum levels of estradiol and progesterone (p < 0.01). The levels of estradiol also decreased in endometriosis lesions at doses of 12.5 and 50 mg/kg (p < 0.001). Both malondialdehyde and glutathione levels increased in endometriosis lesions (p < 0.001). The ectopic endometrium height decreased and the number of antral follicles and corpora lutea (p < 0.05) increased while that of luteinized unruptured follicles decreased (p < 0.001). In conclusion, the ethanol extract of P. americana seeds displayed an antiendometriosis effect suggesting that it could be a potential alternative for the treatment of endometriosis.

NPPB prevents postoperative peritoneal adhesion formation by blocking volume-activated Cl- current.

5-Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) is a non-specific chloride channel blocker. Peritoneal adhesion is an inevitable complication of abdominal surgery and remains an important clinical problem, leading to chronic pain, intestinal obstruction, and female infertility. The aim of this study is to observe the effects of NPPB on peritoneal adhesions and uncover the underlying mechanism. The formation of postoperative peritoneal adhesions was induced by mechanical injury to the peritoneum of rats. MTT assay and wound-healing assay were used to evaluate proliferation and migration of primary cultured adhesion fibroblasts (AFB) respectively. Whole-cell chloride currents were measured using a fully automated patch-clamp workstation. Cell volume changes were monitored by light microscopy and video imaging. Our results demonstrated that NPPB could significantly prevent the formation of peritoneal adhesion in rats and inhibit the proliferation of AFB in a concentration-dependent manner. NPPB also reduced the migration of AFB cells with an IC50 of 53.09 μM. A 47% hypotonic solution successfully activated the ICl,vol in AFB cells. The current could be blocked by extracellular treatment with NPPB. Moreover, 100 μM NPPB almost completely eliminated the capacity of regulatory volume decrease (RVD) in these cells. These data indicate that NPPB could prevent the formation of postoperative peritoneal adhesions. The possible mechanism may be through the inhibition of the proliferation and migration of AFB cells by modulating ICl,vol and cell volume. These results suggest a potential clinical use of NPPB for preventing the formation of peritoneal adhesions.

Curcumin ameliorates peritoneal fibrosis via inhibition of transforming growth factor-activated kinase 1 (TAK1) pathway in a rat model of peritoneal dialysis

BackgroundPeritoneal fibrosis (PF) remains a serious complication of long-term peritoneal dialysis (PD). The goal of this study was to investigate the anti-fibrotic effects of curcumin on the PF response to PD and its’ mechanism.MethodsMale Sprague–Dawley rats were infused with 20 mL of 4.25% glucose-based standard PD fluid for 8 consecutive weeks to establish PF model and then divided into five groups: Control, received sham operation and 0.9% physiological saline; PD, received 4.25% standard PD fluid; Curcumin, PD rats injected intraperitoeally with curcumin for 8 weeks at doses of 10, 20 or 40 mg/kg. Masson’s staining was performed to evaluate the extent of PF. Peritoneal Equilibration Test (PET) was conducted to assess ultrafiltration volume (UFV) and mass transfer of glucose (MTG), quantitative RT-PCR, and immunohistochemistry or western blotting were performed to measure the expression levels of inflammation and fibrosis-associated factors. We also detected the TGF-β1 in peritoneal fluid by ELISA.ResultsCompared with the control group, the PD rats showed decreased UFV (2.54 ± 0.48 to 9.87 ± 0.78 mL, p < 0.05] and increased MTG (18.99 ± 0.86 to 10.85 ± 0.65 mmol/kg, p < 0.05) as well as obvious fibroproliferative response, with markedly increased peritoneal thickness (178.33 ± 4.42 to 25.26 ± 0.32um, p < 0.05) and higher expression of a-SMA, collagen I and TGF-β1. Treatment with curcumin significantly increased UFV, reduced MTG and peritoneal thickness of PD rats. The elevated TGF-β1 in peritoneal fluid of PD rats was significantly decreased by curcumin. It attenuated the increase in protein and mRNA of TGF-β1, α-SMA and collagen I in peritoneum of PD rats. The mRNA expressions of TAK1, JNK and p38, as well as the protein expressions of p-TAK1, p-JNK and p-p38 in peritoneum of PD rats were reduced by curcumin.ConclusionsPresent results demonstrate that curcumin showed a protective effect on PD-related PF and suggest an implication of TAK1, p38 and JNK pathway in mediating the benefical effects of curcumin.