Genetic profile of Brazilian patients with LAMA2-related dystrophies.

LAMA2-related dystrophies (LAMA2-RD) constitute a rare neuromuscular disorder with a broad spectrum of phenotypic severity. Our understanding of the genotype-phenotype correlations in this condition remains incomplete, and reliable clinical data for clinical trial readiness is limited. In this retrospective study, we reviewed the genetic data and medical records of 114 LAMA2-RD patients enrolled at seven research centers in Brazil. We identified 58 different pathogenic variants, including 21 novel ones. Six variants were more prevalent and were present in 81.5% of the patients. Notably, the c.1255del, c.2049_2050del, c.3976 C>T, c.5234+1G>A, and c.4739dup variants were found in patients unable to walk and without cortical malformation. In contrast, the c.2461A>C variant was present in patients who could walk unassisted. Among ambulatory patients, missense variants were more prevalent (p < 0.0001). Although no specific hotspot regions existed in the LAMA2, 51% of point mutations were in the LN domain, and 88% of the missense variants were found within this domain. Functional analysis was performed in one intronic variant (c.4960-17C>A) and revealed an out-of-frame transcript, indicating that the variant creates a cryptic splicing site (AG). Our study has shed light on crucial phenotype-genotype correlations and provided valuable insights, particularly regarding the Latin American population.

SARS-CoV-2 infection causes intestinal cell damage: Role of interferon's imbalance.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of the newly emerging lung disease pandemic COVID-19. This viral infection causes a series of respiratory disorders, and although this virus mainly infects respiratory cells, the small intestine can also be an important site of entry or interaction, as enterocytes highly express in angiotensin-2 converting enzyme (ACE) receptors. There are countless reports pointing to the importance of interferons (IFNs) with regard to the mediation of the immune system in viral infection by SARS-CoV-2. Thus, this review will focus on the main cells that make up the large intestine, their specific immunology, as well as the function of IFNs in the intestinal mucosa after the invasion of coronavirus-2.

Bromazepam increases the error of the time interval judgments and modulates the EEG alpha asymmetry during time estimation.

AIM: This study investigated the bromazepam effects in male subjects during the time estimation performance and EEG alpha asymmetry in electrodes associated with the frontal and motor cortex. MATERIAL AND METHODS: This is a double-blind, crossover study with a sample of 32 healthy adults under control (placebo) vs. experimental (bromazepam) during visual time-estimation task in combination with electroencephalographic analysis. RESULTS: The results demonstrated that the bromazepam increased the relative error in the 4 s, 7 s, and 9 s intervals (p = 0.001). In addition, oral bromazepam modulated the EEG alpha asymmetry in cortical areas during the time judgment (p ≤ 0.025). CONCLUSION: The bromazepam decreases the precision of time estimation judgments and modulates the EEG alpha asymmetry, with greater left hemispheric dominance during time perception. Our findings suggest that bromazepam influences internal clock synchronization via the modulation of GABAergic receptors, strongly relating to attention, conscious perception, and behavioral performance.

Temperature and pressure dependent rate constants of the reactions of OH• with cyclopentene from variational TST and SS-QRRK methods.

In this work, the pressure- and temperature-dependent reaction rate constants for the hydrogen abstraction and addition of hydroxyl radicals to the unsaturated cyclopentene were studied. Geometries and vibrational frequencies of reactants, products, and transition states were calculated using density functional theory, with single-point energy corrections determined at the domain-based local pair natural orbital-coupled-cluster single double triple/cc-pVTZ-F12 level. The high-pressure limit rate constants were calculated using the canonical variational transition state theory with the small-curvature tunneling approximation. The vibrational partition functions were corrected by the effects of torsional and ring-puckering anharmonicities of the transition states and cyclopentene, respectively. Variational effects are shown to be relevant for all the hydrogen abstraction reactions. The increasing of the rate constants by tunneling is significant at temperatures below 500 K. The pressure dependence on the rate constants of the addition of OH• to cyclopentene was calculated using the system-specific quantum Rice-Ramsperger-Kassel model. The high-pressure limit rate constants decrease with increasing temperature in the range 250-1000 K. The falloff behavior was studied at several temperatures with pressures varying between 10-3 and 103 bar. At temperatures below 500 K, the effect of the pressure on the addition rate constant is very modest. However, at temperatures around and above 1000 K, taking pressure into account is mandatory for an accurate rate constant calculation. Branching ratio analyses reveal that the addition reaction dominates at temperatures below 500 K, decreasing rapidly at higher temperatures. Arrhenius parameters are provided for all reactions and pressure dependent Arrhenius parameters are given for the addition of OH• to cyclopentene.

Photobiomodulation exerts anti-inflammatory effects on the vascular and cellular phases of experimental inflammatory models.

Photobiomodulation therapy (PBMT) is a non-thermal therapeutic procedure widely used in clinical practice. It is considered an effective modality of treatment for the control of various inflammatory conditions with fewer adverse effects as compared to conventional therapy. However, despite the clinical effects, the mechanisms of action and dosimetric parameters of PBMT are not fully understood. This study was performed to describe the effects of two different doses of PBMT on experimental models of inflammation. Male Swiss mice were administered with 0.9% of saline or phlogistic agents (carrageenan, dextran, serotonin, histamine, or bradykinin) by intra-plantar injection and were treated with PBMT at a dose of 1 or 5 J/cm2; right after, the variation of the paw volume was made, and histopathological analysis and myeloperoxidase assay of the carrageenan-induced edematous paw tissues were performed. The action of PBMT on carrageenan-induced vascular permeability was further evaluated. Our results showed that PBMT (1 J/cm2) led to an improvement in paw edema induced by the phlogistic agents and further reduced the histological scores. Inhibition of neutrophil migration was observed following the administration of 1 and 5 J/cm2 of PBMT. However, only 1 J/cm2 of PBMT showed beneficial effects on carrageenan-induced edema. Laser at a dose of 1 J/cm2 showed cellular and vascular effects since it was able to reverse all the inflammatory parameters, and laser at a dose of 5 J/cm2 probably has only cellular effects in the presence of acute inflammation.

The transposable element-rich genome of the cereal pest Sitophilus oryzae.

BACKGROUND: The rice weevil Sitophilus oryzae is one of the most important agricultural pests, causing extensive damage to cereal in fields and to stored grains. S. oryzae has an intracellular symbiotic relationship (endosymbiosis) with the Gram-negative bacterium Sodalis pierantonius and is a valuable model to decipher host-symbiont molecular interactions. RESULTS: We sequenced the Sitophilus oryzae genome using a combination of short and long reads to produce the best assembly for a Curculionidae species to date. We show that S. oryzae has undergone successive bursts of transposable element (TE) amplification, representing 72% of the genome. In addition, we show that many TE families are transcriptionally active, and changes in their expression are associated with insect endosymbiotic state. S. oryzae has undergone a high gene expansion rate, when compared to other beetles. Reconstruction of host-symbiont metabolic networks revealed that, despite its recent association with cereal weevils (30 kyear), S. pierantonius relies on the host for several amino acids and nucleotides to survive and to produce vitamins and essential amino acids required for insect development and cuticle biosynthesis. CONCLUSIONS: Here we present the genome of an agricultural pest beetle, which may act as a foundation for pest control. In addition, S. oryzae may be a useful model for endosymbiosis, and studying TE evolution and regulation, along with the impact of TEs on eukaryotic genomes.

Renal alterations caused by ligature-induced periodontitis persist after ligature removal in rats.

BACKGROUND AND OBJECTIVE: Periodontitis may crosstalk with renal diseases, yet that remains unclear. We investigated whether the renal alterations caused by induced periodontitis are reversible after removal of the ligatures in experimental ligature-induced periodontitis. MATERIAL AND METHODS: Twenty-four female rats were divided into three groups: control (without periodontitis), periodontitis (20 days of ligature-induced periodontitis), and P20-20 (20 days of ligature-induced periodontitis and 20 days after ligature removal). The following periodontal parameters were assessed: gingival bleeding index, probing pocket depth, myeloperoxidase activity, and alveolar bone height. For renal tissues, histopathology, malonaldehyde (MDA) levels, glutathione (GSH) content, and renal weight were evaluated. In the blood, creatinine, uric acid, albumin, total cholesterol, total protein, and glucose levels were assessed. Total protein and creatinine levels in urine were also investigated. RESULTS: Rat renal tissues did not demonstrate reversal of periodontitis-related changes in the P20-20 group in terms of MDA, GSH, and histopathological evaluations when compared to the periodontitis group. Accordingly, only total cholesterol levels were reversible in the P20-20. CONCLUSION: Renal alterations caused by ligature-induced periodontitis persisted even after removal of ligatures in rats.

Euterpe oleracea Mart. (Açaí) attenuates experimental colitis in rats: involvement of TLR4/COX-2/NF-ĸB.

Euterpe oleracea Mart., commonly known as açaí, has been demonstrated to exhibit significantly antioxidant and inflammatory activities in experimental models. These effects of the hydroalcoholic extract from the açaí seed (ASE) were investigated in TNBS-induced (2,4,6-trinitrobenzenesulfonic acid) acute colitis model in rats. Wistar rats (180-220 g) were orally pretreated with saline (0.3 mL), ASE (10, 30 and 100 mg/kg) and dexamethasone (control group, 1 mg/kg) once daily for 3 days starting before TNBS instillation. On day 3 after TNBS, the animals were euthanized, the portion of distal colon was collected and washed with 0.9% saline for macroscopy and histological evaluation, glutathione (GSH) and malonyldialdehyde (MDA) levels, myeloperoxidase (MPO) and catalase (CAT) activity, nitrate and nitrite (NO3/NO2) concentration, pro-inflammatory cytokines levels and intestinal barrier integrity. We also evaluated Toll-like Receptor 4/cyclooxygenase-2/nuclear factor kappa B expression as a possible mechanism related to the ASE effects. Treatment with ASE 100 mg/kg decreased significantly macroscopic and microscopic damage induced by TNBS. In addition, MPO activity, TNF-α (tumor necrosis factor-alpha) and IL-1ß (interleukin 1) levels were reduced in rats with colitis. ASE 100 mg/kg restored GSH and MDA levels, CAT activity, NO3/NO2 concentration and improved the intestinal barrier integrity in the TNBS group. ASE 100 mg/kg significantly reduced TNBS-induced expression of the TLR4, COX-2 and NF-κB p65. ASE 100 mg/kg improved macroscopy and histological parameters, inflammation, intestinal barrier integrity and nitric and oxidative stress through the TLR-4/COX-2/NF-κB pathway.

Modulation of 5-fluorouracil activation of toll-like/MyD88/NF-κB/MAPK pathway by Saccharomyces boulardii CNCM I-745 probiotic.

BACKGROUND AND AIM: Chemotherapy drugs that act via Toll-like receptors (TLRs) can exacerbate mucosal injury through the production of cytokines. Intestinal mucositis can activate TLR2 and TLR4, resulting in the activation of NF-κB. Intestinal mucositis characterized by intense inflammation is the main side effect associated with 5-fluorouracil (5-FU) treatment. Saccharomyces boulardii CNCM I-745 (S.b) is a probiotic yeast used in the treatment of gastrointestinal disorders. The main objective of the study was to evaluate the effect of S.b treatment on the Toll-like/MyD88/NF-κB/MAPK pathway activated during intestinal mucositis and in Caco-2 cells treated with 5-FU. METHODS: The mice were divided into three groups: saline (control), saline + 5-FU, and 5-FU + S.b (1.6 × 1010 colony forming units/kg). After 3 days of S.b administration by gavage, the mice were euthanized and the jejunum and ileum were removed. In vitro, Caco2 cells were treated with 5-FU (1 mM) alone or in the presence of lipopolysaccharide (1 ng/ml). When indicated, cells were exposed to S.b. The jejunum/ileum samples and Caco2 cells were examined for the expression or concentration of the inflammatory components. RESULTS: Treatment with S.b modulated the expressions of TLR2, TLR4, MyD88, NF-κB, ERK1/2, phospho-p38, phospho-JNK, TNF-α, IL-1ß, and CXCL-1 in the jejunum/ileum and Caco2 cells following treatment with 5-FU. CONCLUSION: Toll-like/MyD88/NF-κB/MAPK pathway are activated during intestinal mucositis and their modulation by S.b suggests a novel and valuable therapeutic strategy for intestinal inflammation.

Probiotic mixture containing Lactobacillus spp. and Bifidobacterium spp. attenuates 5-fluorouracil-induced intestinal mucositis in mice.

Lactobacillus spp. and Bifidobacterium spp. was used to protect against gastrointestinal disorders. The present study evaluated the effects of probiotic mixture (PM) containing Lactobacillus spp. and Bifidobacterium spp. on intestinal mucositis induced by 5-fluorouracil (5-FU). Swiss male mice (25-30 g) were treated with 5-FU (450 mg/kg, ip) and were orally administered (PM). Probiotic mixture 1 (PM-1) is a mixture of two probiotics (Lactobacillus acidophilus and Bifidobacterium lactis) and probiotic mixture 2 (PM-2) is a mixture of four probiotics (Lactobacillus acidophilus, Lactobacillus paracasei, Lactobacillus rhamnosus, and Bifidobacterium lactis). PM-1 and PM-2 decreased histopathological scores in the duodenum and jejunum after mucositis. PM-2 attenuated 5-FU-induced weight loss. On the other hand, PM-1 did not exert a significant effect on weight loss. Both probiotics mixture increased the villus/crypt ratio in all intestinal segments, increased GSH levels in the duodenum and jejunum, and reduced the MDA, MPO, TNF-α, and IL-6 levels in the duodenum, jejunum, and ileum. PM-2 attenuated the delay in gastric emptying. PM-1 and PM-2 prevented epithelial injury in intestinal mucositis by 5-FU, demonstrating the potential use of these probiotics as therapeutic agents against intestinal mucositis.

Alpha-terpineol complexed with beta-cyclodextrin reduces damages caused by periodontitis in rats.

BACKGROUND AND OBJECTIVE: This study aimed to assess the effectiveness of the treatment with alpha-terpineol (αTPN) complexed with beta-cyclodextrin (ßCD) on oral, blood, and hepatic parameters in ligature-induced periodontitis. MATERIAL AND METHODS: Forty female rats were distributed among the following groups: control (vehicle solution), periodontitis (ligature + vehicle solution), 5 mg/kg of αTPN-ßCD (ligature), and 25 mg/kg of αTPN-ßCD (ligature). Compounds were administered daily via intraperitoneal injection over a 20-day period. Periodontitis was induced with the bilateral insertion of ligatures around the first lower molars of each rat. Oral parameters, as well as blood biomarkers, were measured: histopathological assessment of the hepatic tissue was carried out using light and transmission electron microscopy. RESULTS: The treatment with αTPN-ßCD significantly improved several oral parameters and blood biomarkers in comparison with rats with periodontitis. In addition, the treatment with αTPN-ßCD significantly ameliorated the steatosis score and reduced the number of lipid droplets and the amount of foamy cytoplasm in the hepatocytes of rats with periodontitis. CONCLUSION: The results obtained suggest that the treatment with αTPN-ßCD improves several oral and blood parameters in rats with experimental periodontitis. In addition, hepatic alterations caused by periodontitis were ameliorated in the rats treated with αTPN-ßCD.

Putative contributions of the sex chromosome proteins SOX3 and SRY to neurodevelopmental disorders.

The male-biased prevalence of certain neurodevelopmental disorders and the sex-biased outcomes associated with stress exposure during gestation have been previously described. Here, we hypothesized that genes distinctively targeted by only one or both homologous proteins highly conserved across therian mammals, SOX3 and SRY, could induce sexual adaptive changes that result in a differential risk for neurodevelopmental disorders. ChIP-seq/chip data showed that SOX3/SRY gene targets were expressed in different brain cell types in mice. We used orthologous human genes in rodent genomes to extend the number of SOX3/SRY set (1,721). These genes were later found to be enriched in five modules of coexpressed genes during the early and mid-gestation periods (FDR < 0.05), independent of sexual hormones. Genes with differential expression (24, p < 0.0001) and methylation (40, p < 0.047) between sexes were overrepresented in this set. Exclusive SOX3 or SRY target genes were more associated with the late gestational and postnatal periods. Using autism as a model sex-biased disorder, the SOX3/SRY set was enriched in autism gene databases (FDR ≤ 0.05), and there were more de novo variations from the male autism spectrum disorder (ASD) samples under the SRY peaks compared to the random peaks (p < 0.024). The comparison of coexpressed networks of SOX3/SRY target genes between male autism and control samples revealed low preservation in gene modules related to stress response (99 genes) and neurogenesis (78 genes). This study provides evidence that while SOX3 is a regulatory mechanism for both sexes, the male-exclusive SRY also plays a role in gene regulation, suggesting a potential mechanism for sex bias in ASD.

Assessing the Molecular Basis of the Fuel Octane Scale: A Detailed Investigation on the Rate Controlling Steps of the Autoignition of Heptane and Isooctane.

N-Heptane and 2,2,4-trimethylpentane (isooctane) are the key species in the modeling of ignition of hydrocarbon-based fuel formulations. Isooctane is knock-resistant whereas n-heptane is a very knock-prone hydrocarbon. It has been suggested that interconversion of their associated alkylperoxy and hydroperoxyalkyl species via hydrogen-transfer isomerization reaction is the key step to understand their different knocking behavior. In this work, the kinetics of unimolecular hydrogen-transfer reactions of n-heptylperoxy and isooctylperoxy are determined using canonical variational transition-state theory and multidimensional small curvature tunneling. Internal rotation of involved molecules is taken explicitly into account in the molecular partition function. The rate coefficients are calculated in the temperature range 300-900 K, relevant to low-temperature autoignition. The concerted HO2 elimination is an important reaction that competes with some H-transfer and is associated with chain termination. Thus, the branching ratio between these reaction channels is analyzed. We show that variational and multidimensional tunneling effects cannot be neglected for the H-transfer reaction. In particular, the pre-exponential Arrhenius fitting parameter derived from our rate constants shows a strong dependence on the temperature, because tunneling increases quickly at temperatures below 500 K. On the basis of our results, the existing qualitative model for the reasons for different knock behavior observed for n-heptane and isooctane is quantitatively validated at the molecular level.

Photobiomodulation reduces neutrophil migration and oxidative stress in mice with carrageenan-induced peritonitis.

The purpose of the study is to investigate the effects of two doses of photobiomodulation (PBM) on inflammatory parameters including cell migration and oxidative stress in carrageenan-induced peritonitis models. Twenty-eight mice were divided into four groups: saline; untreated carrageenan (Cg; inflammation induced); and PMB treatment groups L1 and L5 (inflammation induced with carrageenan followed by laser irradiation at 1 and 5 J/cm2, respectively). After 30 min of inducing inflammation, laser irradiation was administered every hour, for 4 h. Peritoneal fluid was collected for analyses. The total leukocyte number in the peritoneal fluid in L1 (4.33 ± 2.34) and L5 (4.95 ± 2.86) after PBM was lower than that in Cg (10.93 ± 5.15 cells/ml). The average differential count of neutrophils in the Cg was 9.46 ± 4.31 cells/ml, which was higher than that in L1 (3.7 ± 2.08) and L5 (4.94 ± 2.57). Myeloperoxidase activity was also lower in L1 (1.89 ± 0.43) and L5 (4.84 ± 2.62) than in Cg (22.92 ± 4.52 UMPO/ml). Malondialdehyde content was lower in L1 (137.5 ± 12.33) and L5 (169.6 ± 22.77) than in Cg (345.7 ± 65.67 nmol/ml). Glutathione peroxidase concentration was significantly higher in L1 (155.2 ± 12.43) and L5 (145.9 ± 9.585) than in Cg (79.75 ± 9.567 µ/ml). Nitrite concentration was lower in L1 (0.3317 µM ± 0.0669) and L5 (0.2429 µM ± 0.0232) than in Cg (0.8380 µM ± 0.01615). Laser irradiation at 1 and 5 J/cm2 reversed the inflammation (as indicated by neutrophil infiltration and oxidative stress).

Periodontitis changes renal structures by oxidative stress and lipid peroxidation.

OBJECTIVE: The aim of this study was to investigate whether experimental periodontitis cause changes to the renal tissues and imbalance in oxidative stress in kidneys. METHODS: Twenty-two female Wistar rats were separated into two groups: control and periodontitis. We assessed the following parameters: gingival bleeding index (GBI), tooth mobility, gum malondialdehyde (MDA), myeloperoxidase (MPO) activity, probing pocket depth (PPD), alveolar bone loss (ABL) for periodontal tissues; histomorphometric measures associated with renal corpuscle and histopathological aspects (evaluation of brush border) for kidneys; as also blood and urine biomarkers. Finally, we evaluated renal oxidative stress through glutathione (GSH) and MDA respectively. RESULTS: With regard to renal histomorphometry, significant differences were observed in all parameters assessed. In relation periodic acid Schiff (PAS) staining, disruption was observed of brush border in the periodontitis group in the renal tubules in comparison with the control group. The periodontitis group presented significantly higher MDA and lower GSH concentrations in the kidneys compared with animals without periodontitis. CONCLUSION: The induced periodontitis caused histomorphometric changes in renal tissues as well as disruption of the brush border in renal tubules, alterations associated with increase in oxidative stress in kidneys. However, these alterations were not sufficient to cause differences in the renal function markers.

Antimicrobial resistance, integron carriage, and gyrA and gyrB mutations in Pseudomonas aeruginosa isolated from dogs with otitis externa and pyoderma in Brazil.

BACKGROUND: Pseudomonas aeruginosa is associated with otitis and pyoderma in dogs and is frequently resistant to several antimicrobial drugs. Resistance genes can be carried by integrons with quinolone resistance mainly due to mutations in DNA topoisomerases II and IV. OBJECTIVE: To evaluate the antimicrobial susceptibility, integron carriage, and gyrA and gyrB mutations in P. aeruginosa isolates from canine otitis and pyoderma. ANIMALS: One hundred and four P. aeruginosa strains isolated from dogs with otitis externa (n = 93) and pyoderma (n = 11). METHODS: Antimicrobial susceptibility against 16 antibacterial agents was evaluated through agar diffusion tests. Integron carriage, class and gyrA and gyrB mutations were analysed by PCR, restriction fragment length polymorphism (RFLP)-PCR and genetic sequencing assays. RESULTS: Isolates were mostly resistant to enrofloxacin (72.2%) and ticarcillin (59.7%). Lower resistance to ciprofloxacin (7.7%), tobramycin (3.8%) and polymixin B (0.0%) was detected. Ten (9.6%) multidrug-resistant (MDR) strains were detected. Eight (7.7%) strains carried class 1 integrons and this was associated with MDR (three isolates, P ≤ 0.05). Five of the integron-carrying strains exhibited aminoglycoside resistance genes. Mutations of gyrA and gyrB were observed in 10 isolates, seven of them resistant to all fluoroquinolones tested. CONCLUSIONS AND CLINICAL IMPORTANCE: Enrofloxacin and ticarcilin resistance was widespread in P. aeruginosa isolated from dogs in Brazil. Pseudomonas aeruginosa carrying integrons may present a significant challenge for treatment.

Gastroprotective properties of cashew gum, a complex heteropolysaccharide of Anacardium occidentale, in naproxen-induced gastrointestinal damage in rats.

Long-term use nonsteroidal anti-inflammatory drug is associated with gastrointestinal (GI) lesion formation. The aim of this study was to investigate the protective activity of cashew gum (CG), a complex heteropolysaccharide extracted from Anacardium occidentale on naproxen (NAP)-induced GI damage. Male Wistar rats were pretreated with vehicle or CG (1, 3, 10, and 30 mg/kg, p.o.) twice daily for 2 days; after 1 h, NAP (80 mg/kg, p.o.) was administered. The rats were euthanized on the 2nd day of treatment, 4 h after NAP administration. Stomach lesions were measured using digital calipers. The medial small intestine was used for the evaluation of macroscopic lesion scores. Samples of the stomach and the intestine were used for histological evaluation, and assays for glutathione (GSH), malonyldialdehyde (MDA), and myeloperoxidase (MPO). Additional rats were used to measure gastric mucus and secretion. Pretreatment with CG reduced the macroscopic and microscopic damage induced by NAP. CG significantly attenuated NAP-induced alterations in MPO, GSH, and MDA levels. Furthermore, CG returned adherent mucus levels to normal values. These results suggest that CG has a protective effect against GI damage via mechanisms that involve the inhibition of inflammation and increasing the amount of adherent mucus in mucosa.

Alendronate induces gastric damage by reducing nitric oxide synthase expression and NO/cGMP/K(ATP) signaling pathway.

Chronic use of alendronate has been linked to gastrointestinal tract problems. Our objective was to evaluate the role of the NO/cGMP/KATP signaling pathway and nitric oxide synthase expression in alendronate-induced gastric damage. Rats were either treated with the NO donor, sodium nitroprusside (SNP; 1, 3, and 10 mg/kg), or the NO synthase (NOS) substrate, L-arginine (L-Arg; 50, 100, and 200 mg/kg). Some rats were pretreated with either ODQ (a guanylate cyclase inhibitor; 10 mg/kg) or glibenclamide (KATP channels blocker; 10 mg/kg). In other experiments, rats were pretreated with L-NAME (non-selective NOS inhibitor; 10 mg/kg), 1400 W (selective inducible NOS [iNOS] inhibitor; 10 mg/kg), or L-NIO (a selective endothelial NOS [eNOS] inhibitor; 30 mg/kg). After 1 h, the rats were treated with alendronate (30 mg/kg) by gavage for 4 days. SNP and L-Arg prevented alendronate-induced gastric damage in a dose-dependent manner. Alendronate reduced nitrite/nitrate levels, an effect that was reversed with SNP or L-Arg treatment. Pretreatment with ODQ or glibenclamide reversed the protective effects of SNP and L-Arg. L-NAME, 1400 W, or L-NIO aggravated the severity of alendronate-induced lesions. In addition, alendronate reduced the expression of iNOS and eNOS in the gastric mucosa. Gastric ulcerogenic responses induced by alendronate were mediated by a decrease in NO derived from both eNOS and iNOS. In addition, our findings support the hypothesis that activation of the NO/cGMP/KATP pathway is of primary importance for protection against alendronate-induced gastric damage.

Colitis generates remote antinociception in rats: the role of the L-arginine/NO/cGMP/PKG/KATP pathway and involvement of cannabinoid and opioid systems.

OBJECTIVE AND DESIGN: The aim of this study was to investigate the possible involvement of the NO/cGMP/PKG/KATP+ pathway, cannabinoids and opioids in remote antinociception associated with 2,4,6-trinitrobenzene sulph onic acid (TNBS)-induced colitis. METHODS: TNBS-induced colitis was induced by intracolonic administration of 20 mg of TNBS in 50% ethanol. After induction, carrageenan (500 µg/paw) or prostaglandin (PG) E2 (100 ng/paw) was injected in the rat's plantar surface and hypersensitivity was evaluated by the electronic von Frey test. Rats were pre-treated with L-Noarg one hour before carrageenan injection. L-Arginine was given 10 min before L-Noarg injections. ODQ, KT 5823, glibenclamide (Glib), naloxone and AM 251 or AM 630 were administered 30 min prior to carrageenan or PGE2 treatments. RESULTS: Colitis induction by TNBS reduced PGE2 or carrageenan-induced hypersensitivity. Antinociception produced by TNBS-induced colitis was reversed significantly (P<0.05) by L-Noarg, ODQ, KT 5823, glibenclamide, naloxone, AM251 and AM630 treatments. CONCLUSIONS: TNBS-induced colitis causes antinociception in the rat paw. This disorder appears to be mediated by activation of the NO/cGMP/PKG/KATP pathway, endocannabinoids and endogenous opioids. This information may contribute to a better understanding of peripheral neurological dysfunctions occurring in Crohn's disease.