The impact of subdermal adipose derived stem cell injections and early excision on systemic oxidative stress and wound healing in rats with severe scald burns.

AIM: This study aims to develop an experimental treatment model effective against oxidative stress in the acute period of severe burns and to analyze the mechanisms of healing large wound defects. METHODS: Five rats, including 2 females and 3 males, were used as donors to obtain adipose-derived stem cells (ADSC) from the inguinal fat pad. The stem cells were labeled with green fluorescent protein. The study included four groups of 17 rats, each with grade 3 scalding burns on 30 % of their body surface, and a control group of 10 rats with an equal number of males and females. After early excision, 106 ADSC-derived stem cells were administered subdermally to the burned wound and autografted to the stem cell group (n = 17). The early excision group (n = 17) received early excision and autograft, with 2 ml of normal saline injected subdermally into the burn wound edge. The PLM group (n = 17) was treated with a polylactic membrane (PLM) dressing after the burn. No treatment was given to the burn group (n = 17). Ten rats from all groups were sacrificed on the 4th day post-burn for oxidative stress evaluation. The control group (n = 10) was sacrificed on day 4. Blood and tissue samples were collected post-sacrifice. Oxidative stress and inflammation in the blood, as well as cell damage in the skin, liver, kidneys, and lungs, were investigated histopathologically and biochemically on the 4th day post-burn. On the 70th day after burn, wound healing was examined macroscopically and histopathologically. RESULTS: On the 4th day, oxidative stress results showed that the levels of Total Oxidative Capacity (TOC) in the blood were lowest in the stem cell (7.4 [6-8.8]), control (6.7 [5.9-7.6]), and early excision (7.5 [6.6-8.5]) groups, with no significant difference between them. The burn group (14.7 [12.5-16.9]) had the highest TOC levels. The PLM group (9.7 [8.6-10.7]) had lower TOC levels than the burn group but higher levels than the other groups. Histopathological examination on the 4th day revealed low liver caspase-3 immunoreactivity in the stem cell and early excision groups among the burn groups. Caspase-3 immunoreactivity levels were as follows: stem cell group (20 [10-30]), early excision group (25 [15-50]), PLM group (70 [50-100]), control group (0), and burn group (80 [60-120]). Other oxidative stress and end-organ damage outcomes were consistent with these results. All rats in the stem cell group had burn wounds that healed completely by the 70th day. Examination of the skin and its appendages from the stem cell group with an immunofluorescence microscope demonstrated green coloration, indicating incorporation of stem cells. CONCLUSION: Stem cells may have the potential to form new skin and its appendages, providing better healing for large skin defects. Early excision treatment, by removing local necrotic tissues after extensive and deep burns, can prevent end-organ damage due to systemic oxidative stress and inflammation. We also believe that when these two treatments are used together, they can achieve the best results.

Efficacy and safety of Hyadex for treatment of vesicoureteral reflux: a multicenter experience.

OBJECTIVE: This study was performed to evaluate the efficacy and safety of dextranomer/cross-linked hyaluronic acid (Hyadex) in patients with a clinical diagnosis of vesicoureteral reflux (VUR). METHODS: In this cross-sectional multicenter observational study, Hyadex was used in four different centers for the endoscopic treatment of VUR from 2020 to 2022. The study involved 74 patients (93 renal units) who were diagnosed with VUR according to voiding cystourethrography (VCUG) findings and were considered suitable for subureteric endoscopic treatment. The follow-up time (control VCUG time) was 3 months. RESULTS: In the VCUG evaluation, grade I VUR was found in 13 renal units, grade II in 23 renal units, grade III in 42 renal units, and grade IV in 12 renal units. The success rates of Hyadex treatment according to the degree of VUR were as follows: 84.6% for grade I, 82.6% for grade II, 71.4% for grade III, and 66.0% for grade IV. No major complications were observed. CONCLUSION: Endoscopic subureteric Hyadex injection had high success rates in appropriately selected patients with VUR and may be used as the first-line treatment for children with VUR.

Impact of COVID-19 pandemic on pediatric appendicitis hospital admission time and length of hospital stay.

BACKGROUND: Appendicitis is one of the most common surgical emergencies among children. In this retrospective clinical study, we attempted to determine the effects of the COVID-19 pandemic period on hospital admission time and length of hospital stay (LOS) in pediatric appendicitis cases. METHODS: We retrospectively compared pediatric appendectomies from the date of the first reported COVID-19 case to June 1, 2020, which is considered as the start of the normalization process, with pre-pandemic pediatric appendectomies of the same number of days in terms of age, gender, hospital admission time, LOS, parental educational level, laboratory values, and histopathological findings. RESULTS: There was an average increase of 2 days in the time from the onset of symptoms to hospital admission in pediatric appen-dicitis patients in the COVID-19 period (p=0.001). Furthermore, C-reactive protein value was statistically significantly higher in the COVID-19 period (p=0.018). Given the LOS, it was calculated as an average of 5 days in the pre-pandemic period and 4 days in the COVID-19 period, and this difference was statistically insignificant (p=0.273). There was no significant difference between the groups in terms of histopathological findings (p=0.176). The parental educational level had no effect on the admission time. CONCLUSION: The hospital admission time of pediatric appendicitis patients is significantly prolonged in the COVID-19 pandemic, but this prolongation had no histopathological effect. During the pandemic, the recovery of patients who required urgent treatment during the 'stay-at-home' period was also negatively affected. Notwithstanding, we are of the opinion that the absence of an increase in the LOS may be due to the willingness of both families and physicians to keep the LOS as short as possible. Despite the increase in hospital admission time in pediatric appendicitis during the Covid 19 pandemic process, the lack of increase in the rate of complicated appendicitis may be an indicator of the importance of other factors in the development of complicated appendicitis.

Comparison of Urinary Tract Dilatation and Society of Fetal Urology systems in the detection of vesicourethral reflux and renal scar.

PURPOSE: The presence and degree of hydronephrosis is very important in the management of many diseases of the urinary tract. In this study, we aim to compare the sensitivity and specificity of 2 classification systems that are used for hydro-nephrosis grading in ultrasound, for reflux and scar detection. The classification systems were the Society of Fetal Urology (SFU) and Urinary Tract Dilatation (UTD). MATERIAL AND METHODS: Ultrasounds and dimercaptosuccinic acid scintigraphies (DMSA) of all patients who underwent voiding cystourethrogram (VCUG) due to urinary tract infection were examined retrospectively. DMSA was accepted for scar detection and VCUG for reflux detection as reference methods. SFU classification was used for hydronephrosis in ultrasound reports, and UTD classification was made over the reports. Sensitivity, specificity, and positive and negative predictive values of UTD and SFU classification systems for reflux and scar detection were calculated, and these 2 systems were compared. RESULTS: 103 (39%) of the patients were male and 162 (61%) were female. Pathologies were detected in 192 (35%) of 530 kidneys in ultrasound. In 110 (42%) of the children, reflux was detected in VCUG. Scars in DMSA were detected in only 16% (44) of 266 kidneys. Sensitivity, positive and negative predictive values of the UTD classification system were statistically significantly higher than the SFU system for scar and reflux detection (p < 0.01). CONCLUSIONS: If we use the UTD system in ultrasounds of patients with urinary tract infections, children reported as UTD 0 may not need VCUG, which reduces radiation exposure to children and the cost of the diagnostic interventions.

Glial Cell Line-Derived Neurotrophic Factor, S-100 Protein and Synaptophysin Expression in Biliary Atresia Gallbladder Tissue.

PURPOSE: Biliary atresia (BA) is a disease that manifests as jaundice after birth and leads to progressive destruction of the ductal system in the liver. The aim of this study was to investigate histopathological changes and immunohistochemically examine the expression of glial cell line-derived neurotrophic factor (GDNF), synaptophysin, and S-100 protein in the gallbladder of BA patients. METHODS: The study included a BA group of 29 patients and a control group of 41 children with cholecystectomy. Gallbladder tissue removed during surgery was obtained and examined immunohistochemically and histopathologically. Tissue samples of both groups were immunohistochemically assessed in terms of GDNF, S-100 protein, and synaptophysin expression. Expression was classified as present or absent. Inflammatory activity assessment with hematoxylin and eosin staining and fibrosis assessment with Masson's trichrome staining were performed for tissue sample sections of both groups. RESULTS: Ganglion cells were not present in gallbladder tissue samples of the BA group. Immunohistochemically, GDNF, synaptophysin, and S-100 expression was not detected in the BA group. Histopathological examination revealed more frequent fibrosis and slightly higher inflammatory activity in the BA than in the control group. CONCLUSION: We speculate that GDNF expression will no longer continue in this region, when the damage caused by inflammation of the extrahepatic bile ducts reaches a critical threshold. The study's findings may represent a missing link in the chain of events forming the etiology of BA and may be helpful in its diagnosis.

Management of anesthesia and complications in children with Tracheobronchial Foreign Body Aspiration.

OBJECTIVES: Delayed diagnosis and treatment of tracheobronchial foreign body aspiration (FBA) in children may lead to morbidity and mortality. Our objective was to evaluate the anesthetic management, peri- and post-operative complications, and predisposing factors for postoperative intensive care unit (ICU) admission in children undergoing rigid bronchoscopy due to tracheobronchial FBA. METHODS: This retrospective study included 81 children who underwent rigid bronchoscopy between January 2010 to July 2018 at Inonu University, Department of Pediatric Surgery, Turkey. Data regarding demographic characteristics, anesthetic management, length of ICU and hospital stays, and peri- and post-operative complications were retrieved from the hospital database. RESULTS: The patients included 54 (66.7%) boys and 27 (33.3%) girls with a mean age of 29.6 ± 31.2 months. The most common presenting symptom was the suspicion of FBA, followed by acute-onset cough, cyanosis, wheezing and respiratory distress. Mean duration of anesthesia was 44.40 ± 14.72 min. Of the 81 patients, 18 (22.2%) were transferred to ICU and 63 (77.8%) patients were transferred to the ward postoperatively. Of the patients transferred to the ICU, 5 of them required mechanical ventilation. Some peri and postoperative complications, desaturation (n=16; 19.7%; p=0.001), mucosal bleeding (n=6; 7.4%; p=0.02), laryngeal edema (n=11; 13.6%; p<0.001), laryngospasm (n=13; 16.3%; p<0.001), were affected the frequency of intensive care transfer. CONCLUSION: Bronchoscopy with general anesthesia remains the golden standard for the management of tracheobronchial FBA. In such patients, a combination consisting of a detailed preoperative clinical evaluation of the patient, selection of short-acting anesthetic agents with minimal side effects for the induction and maintenance of anesthesia, and the administration of controlled ventilation can be recommended. Additionally, early diagnosis of peri- and post-operative complications, prediction of postoperative ICU requirement, and a close cooperation of anesthesiologists and surgeons are highly important.

External hemorrhoidal disease in child and teenage: Clinical presentations and risk factors.

OBJECTIVE: Hemorrhoidal disease (HD), though mostly seen in adults, has recently emerged as a common problem among children. However, the diagnosis and treatment of HD in children is mostly based on the data obtained in adult studies. In this study, we aimed to evaluate risk factors, diagnostic and treatment modalities in the children diagnosed with external HD. METHODS: The study was conducted at Sakarya University Medical School Pediatric Surgery Department between January 2012 and July 2018. We reviewed children who were diagnosed as having HD at Pediatric Surgery clinic. Age, gender, presenting symptoms, physical examination findings, risk factors, and treatment outcomes were evaluated for each patient. RESULTS: The study included 56 patients with a mean age of 140.8±45.2 months. The patients comprised 48 (85.7%) boys and 8 (14.3%) girls. Constipation and a positive family history were the most common risk factor (n=33; 58.9%, n=29; 51.8%, respectively). Conservative treatment was performed in 53 (94.6%) patients. Recurrence was observed in 5 (8.9%) and skin tag was detected in 6 (10.7%) patients. CONCLUSIONS: External HD mostly occurs in boys in their second decade of life. Positive family history and constipation were the most common risk factors in our patients. Conservative treatment is sufficient for the management of external HD in children because of its low recurrence rates.

Use of angiographic embolization in trauma-induced pediatric abdominal solid organ injuries.

BACKGROUND: Knowledge of the utility of angiographic embolization (AE) in pediatric cases of blunt abdominal solid organ trauma injuries is limited. The current study is an examination of AE as an effective and reliable method to control bleeding in patients with persistent bleeding due to blunt trauma-induced abdominal solid organ injury. METHODS: This was a retrospective examination of patients <17 years of age who had experienced blunt abdominal solid organ injury and who presented at a single institution within 4 years. A statistical analysis of the data was performed. RESULTS: The mean length of intensive care unit stay was 4 days for those who underwent embolization (n=11), and the mean length of hospital stay was 12 days. The average pre-AE blood loss, as measured by the decrease in hematocrit (%) from admission to embolization, was -7.33+-5.3% (p<0.001). The average post-AE blood loss, as measured by the change in hematocrit 72 hours post AE, was 2+-0.97% (p>0.05). All of the patients were discharged with a full recovery. CONCLUSION: AE was a safe and effective method to control solid organ hemorrhage in pediatric patients with blunt abdominal injuries.

Risk Factors for Pilonidal Sinus Disease in Teenagers.

OBJECTIVE: To investigate the risk factors for pilonidal sinus in teenagers. METHODS: Between January 2013 and September 2015, 55 teenage patients who underwent surgery due to pilonidal sinus disease (PSD) in the Department of Pediatric Surgery, Sakarya University Teaching and Research Hospital were included in this study. Age, gender, body mass index (BMI), number of baths taken per week, time spent sitting per day, family history, and skin color were examined as risk factors. The control group comprised of healthy teenagers without pilonidal sinus disease. RESULTS: Out of the total 42 teenagers, 23 (54.8 %) were girls and 19 (45.2 %) were boys. Patients were classified as obese, overweight, or normal according to their BMI (14.3 %, 31 %, and 54.8 %, respectively). The number of baths taken per week in the PSD group was lower than that in the control group [odds ratio (OR): 3.690; p = 0.004]. The family history of PSD was significantly higher in teenagers with PSD, compared to the control group (OR: 8.652; p = 0.005). No differences were detected between the PSD and control groups with respect to sitting for ≥ 6 h per day (OR: 3.212; p = 0.028). Skin color was not found to be affected by PSD in teenagers (OR: 1.294; p = 0.392). CONCLUSIONS: Heredity and the number of baths taken per week were found to significantly affect the incidence of PSD, whereas other variables (gender, age, BMI, skin color, and time spent sitting per day) did not exhibit any significant influence on the rate of incidence.

A rare cause of acute abdomen: tumor rupture of nonpalpable testis.

Undescended testicle is the most common congenital anomaly among males. Testicular tumor develops in 3-5% of the boys with a complaint of undescended testicle. The clinical presentation of malignant intra-abdominal testicular tumors ranges from asymptomatic cases to acute abdomen. In this study, we present a child with testicular tumor rupture which is observed very rarely. A 16-year-old boy presented 24 hours after the sudden onset of right lower quadrant pain, nausea, vomiting and fever. On physical examination, extensive tenderness in the abdomen and abdominal guarding were found. The right testicle was not palpable. The serum white blood cell count was elevated. Ultrasonography and abdominal computerized tomography scan demonstrated a perforated, hyperdense mass with free fluid in the abdomen. The preoperative alpha fetoprotein level was found to be increased. We performed surgery with laparoscopy and a perforated right intraabdominal testicle was found in the right iliac fossa. The mass was excised. Histopathological examination revealed a yolk sac tumor. Ruptured nonpalpable testicular tumors are very rare. To our knowledge, this is the first adolescent case reported so far. Testicular tumor rupture should be considered in patients with nonpalpable testicle and acute abdomen. Laparoscopy may be performed in differential diagnosis and treatment of these patients.

Comparison of Polypropylene Mesh and Primary Repair in the Treatment of Blunt Testicular Rupture.

PURPOSE: This study aimed to show the applicability of Polypropylene mesh (PM) grafting in blunt testicular ruptures. MATERIALS AND METHODS: Data of 16 patients treated for testicular rupture following blunt scrotal trauma between March 2007 and April 2015 were analyzed retrospectively. Eight primary repairs and eight PM graftings were performed to repair the tunica albuginea (TA). Postoperatively, patients underwent Doppler ultrasonography at 3 weeks and then at 3, 6, and 12 months, followed by annual scans. The measurement of plasma testosterone levels was performed 12 months after the surgery. RESULTS: The average follow-up time was 24.8 (range 12-48) and 42.8 (range 14-75) months for patients treated with PM grafting and primary repair, respectively. Differences in testicular size between treatment groups were only significant at 12 months postoperatively with the value of 26.5 mL (range 24-28) and 22.8 mL (range 13-27) in patients treated with a PM graft and primary repair, respectively (P = .045). There were no complications for those patients treated with the PM graft. Two patients who underwent primary repair developed testicular atrophy within 1 year postoperatively. CONCLUSION: PM grafting is a safe alternative to primary closure of a TA defect following blunt testicular trauma. .

Antienflamatuar and antiadhesive effect of clioquinol.

BACKGROUNDS/AIMS: The aim of this study is to investigate the expected adhesion-modifying effect of clinoquinol which has metal-chelating feature that limits the inflammation and fibroblastic activity. METHODS: A total of 40 Wistar Albino rats were included, which were divided into 5 groups. Group-1 constituted the sham group. Other groups, adhesions were induced by performing cecal abrasion on the rats. For treatment, saline solution was added to Group-2, carboxymethylcellulose was added to Group-3, methylene blue was added to Group-4, and clioquinol was added to Group-5. Blood samples were obtained from the heart to measure IL-10 and TNF α-levels. Adhesions were evaluated both macroscopically and histopathologically. RESULTS: Clioquinol reduced adhesions at significant level via decreasing the inflammation and fibroblastic activity in the adhesion-induced rats. At macroscopic level, carboxymethylcellulose and clioquinol were the most potent agents in reducing adhesions. Nonetheless, significant foreign body-reaction was observed in the carboxymethylcellulose-treated group. CONCLUSIONS: Clioquinol could reduce the formation of intra-abdominal adhesions. It exerts this activity by limiting the inflammation and fibroblastic activity between the intestines and serous surfaces. Furthermore, it does not induce a foreign body reaction. Due to these properties, we conclude that clioquinol can be used as an alternative agent to prevent adhesions.

Prevention of cyclophosphamide-induced hemorrhagic cystitis by resveratrol: a comparative experimental study with mesna.

PURPOSE: Hemorrhagic cystitis (HC) is the most common urotoxic side effect of cyclophosphamide (CP). The aim of this study was to compare the classical efficacy of mesna (2-mercaptoethane sulfonate sodium) with three different doses of resveratrol (RES) on cyclophosphamide-induced HC in rats. METHODS: Forty-six male Sprague-Dawley rats were divided into six groups. Group 1 served as a negative control (sham). Five groups received a single dose of cyclophosphamide (150 mg/kg) intraperitoneally at the same time. Groups 2, 3, 4, 5, and 6 received only CP, CP + 20 mg/kg RES, CP + 40 mg/kg RES, CP + 80 mg/kg RES, and CP + classical protocol of three doses of mesna (30 mg/kg three times), respectively. Antioxidants, cytokines, and malondialdehyde levels were measured in all groups. In addition, histopathological alterations in tissues were examined. RESULTS: CP administration induced severe HC with marked edema, hemorrhage, and inflammation in group 2. RES 20 mg/kg showed meaningful protection against bladder damage compared to the control group. It was seen that RES 40 mg/kg gave weaker protection but RES 80 mg/kg was not found to be effective. CONCLUSION: In conclusion, marked bladder protection was found in 20 and 40 mg/kg RES applications compared to the control group, but this protection was weaker than with mesna.

Simple patch closure for perforated peptic ulcer in children followed by helicobacter pylori eradication.

OBJECTIVE: Peptic ulcer disease in children is rare. Therefore, the diagnosis can be missed until complications such as perforation or hemorrhage occur. Few reports have investigated the procedures and outcomes of children who have undergone operations for perforated duodenal ulcers. We report our experience with the modified Graham technique for perforated duodenal ulcers in nine children and review the literature. Methods : The records of patients operated on for a perforated duodenal ulcer in the last 8 years in two pediatric surgery centers were evaluated retrospectively. Patient demographics, symptoms, time to admission to hospital, operative findings, and postoperative clinical course were evaluated. Results : Nine children (mean age 13.2 years, range 6-170 years) were included. All patients were admitted in the first six hours after their abdominal pain started. In three patients, there was free air on plain x-rays, while the x-rays were normal in six. All perforations were located on the anterior surface of the first part of the duodenum and repaired with primary suturing and Graham patch omentoplasty. The recovery was uneventful in all patients. In five patients, urea breath tests were performed postoperatively for Helicobacter Pylori, and the results were positive. All patients underwent triple therapy with lansoprazole, amoxicillin, and clarithromycin. The mean follow-up time was 58 (range 3-94) months. Conclusions : Peptic ulcer perforation should be suspected in children who have acute abdominal pain and peritoneal signs, especially when their suffering is intense. The simple patch repair and postoperative triple therapy for Helicobacter Pylori are safe and satisfactory for treating peptic ulcer perforation in children.

[Analysis of risk factors for the development of pediatric appendicitis]. / Çocuk apandisitlerinde risk faktörlerinin analizi.

BACKGROUND: Appendicitis is the most common form of abdominal pain requiring surgery among children. This study evaluates the association of age, sex, seasonal, and familial factors with the histopathology of appendectomies. METHODS: 588 patients who underwent operations for acute appendicitis between 2009 and 2011 were included in this study. The patients were classified in one of three groups based on histopathological results: acute, perforated, and negative appendectomy. This study evaluates the association between age, sex, seasonal, and familial factors and the histopathological classification. RESULTS: The mean age of the patients was 11.8±3.26 years (range 1 to 16 years). Among these patients, appendicitis was 2.41 times more common in children greater than 10 years old. Appendicitis occurred 4.63 times more often among males than in females. Negative appendectomy occurred more often in children greater than 10 years of age. Appendicitis was associated with both seasonal factors and family history; however this association did not meet the threshold for statistical significance (p>0.05). DISCUSSION: The age and sex of the patient should be taken into account when considering appendicitis surgery to improve the accuracy of the diagnosis. In addition, the histopathology of appendicitis is influenced by familial and environmental factors.

Age of patient is a risk factor for urethrocutaneous fistula in hypospadias surgery.

OBJECTIVE: There is still much debate regarding the effect that age at hypospadias operation has on the rate of complications. The aim of this study was to evaluate whether patient age is a risk factor for surgical complications when using the tubularized incised plate (TIP) urethroplasty technique. METHODS: Between 2005 and 2011, 307 pediatric patients with distal or mid-penile hypospadias underwent the TIP procedure. Demographic and surgical data were evaluated. RESULTS: The complications recorded across all age groups were: fistula, meatal stenosis, glans dehiscence and urethral stenosis. Fistula was the most frequent complication in 10-14 year olds compared to the younger patient groups, and this difference was statistically significant. CONCLUSION: Age and surgical technique should be taken into consideration when planning hypospadias surgery, since the complication rate increases with patient age. The TIP technique is a safe procedure with a low rate of fistula formation in distal and mid-penile hypospadias repair for patients of any age during the prepubertal period.

Alterations in spontaneous contractions of rat proximal and distal colon after peritonitis.

BACKGROUND/PURPOSE: The aim of this study was to investigate the effect of peritonitis on spontaneous contractions of distal and proximal colon smooth muscle isolated from rats. METHODS: Peritonitis was induced by cecal ligation and puncture in 8 rats. Another group of 8 rats underwent a sham operation and acted as controls. Twenty-four hours after the operation, the rats were killed; and their distal and proximal colon smooth muscle was excised and placed in circular muscle direction in a 10-mL organ bath. Changes in the amplitude and frequency of contractions were analyzed before and after the addition of antagonists. RESULTS: Peritonitis induced the increase in the amplitude and frequency of spontaneous contractions. In both distal and proximal colon of the control group, the amplitude of spontaneous contractions was elevated by N(G)-nitro-L-arginine and tetrodotoxin; but the frequency of spontaneous contractions was significantly elevated only in the presence of N(G)-nitro-L-arginine. In both distal and proximal colon of the peritonitis group, the enhanced amplitude and frequency were significantly decreased and returned to control values in the presence of celecoxib. CONCLUSIONS: Peritonitis induces the increase in the amplitude and frequency of spontaneous contractions of distal and proximal colon, which can be attributed to a loss of inhibitor nitrergic and other neural control or rise of cyclooxygenase-2 levels.

Effect of L-NAME on decreased ileal muscle contractility induced by peritonitis in rats.

BACKGROUND/PURPOSE: It is now well established that intestinal inflammation is associated with disturbed contractility. The aim of this study was to determine the effects of peritonitis on longitudinal ileum smooth muscle responses to KCl, carbachol and substance P (SP) and to examine the role of nitric oxide (NO) and N(omega)-nitro-L-arginine methylester (L-NAME) on ileal contractility in this peritonitis model. METHODS: Peritonitis was induced by cecal ligation and puncture (CLP) in 20 rats. While 10 of these received 1 mL distilled water as placebo, the other 10 received 5 mg/kg (subcutaneously) L-NAME before the operation. Another group of 10 rats underwent a sham operation. Twenty-four hours after the operation, the rats were killed, and their ileum was excised. Ileum segments were placed in longitudinal direction in a 10-mL organ bath; concentration-response relationship for KCl, carbachol, and SP were obtained by adding the reagent cumulatively to the bath. RESULTS: The KCl-, carbachol-, and SP-induced contractions were decreased markedly, with no change in the pD(2) values in the peritonitis group compared with controls. Peritonitis-induced changes in the contractile responses were restored significantly by in vivo L-NAME pretreatment. CONCLUSIONS: The model of CLP-induced peritonitis in rats showed that KCl-induced nonreceptor-mediated, carbachol- and SP-induced receptor-mediated contractions are significantly decreased by inflammation in the longitudinal ileum muscle. Increased synthesis of NO may be responsible for these decreases in contractile responses because they were restored significantly by in vivo L-NAME injection. Inhibition of NOS with L-NAME injection may afford a new therapeutic approach to the treatment of gastrointestinal stasis in septic patients.