Prostaglandin F2α treatment does not hasten ovulation in weaned sows.

This study evaluated the efficiency of prostaglandin F2α (PGF) to hasten ovulation in weaned sows. In experiment I, weaned sows detected in estrus (0 h) received: no hormone (Control; n = 56); 0.5 mg PGF IM at 0 h and 2 h (PGF0; n = 56); or 0.5 mg PGF IM at 24 h and 26 h (PGF24; n = 55). In experiment II, weaned sows that did not express estrus signs until 72 h after weaning (0 h) were assigned to: no hormone (Control; n = 45); 10 µg buserelin acetate IM at 0 h (Buserelin; n = 43); 0.5 mg PGF IM at 34 h and 36 h (PGF; n = 44); or 10 µg buserelin acetate IM at 0 h plus 0.5 mg PGF IM at 34 h and 36 h (Buserelin + PGF; n = 45). In experiment I, no effect of PGF on the interval treatment onset to ovulation was observed (P > 0.05), and no treatment effect was observed on the relative or cumulative proportion of females that ovulated post-treatment onset (P > 0.05). In experiment II, treatment onset to ovulation interval was shorter for Buserelin group than for PGF group (P < 0.05), and a higher cumulative percentage of Buserelin treated sows ovulated up to 48 h compared to PGF and Control groups (P < 0.01), with no differences from Buserelin + PGF. Treatments did not affect total number of piglets born in both experiments (P > 0.05). In conclusion, PGF did not hasten ovulation timing or affect litter size in weaned sows.

Prevalence of enteroparasitic infections and related hormonal and immunological repercussions that may compromise students' physical performance.

The aim of this study was to evaluate the prevalence of enteroparasitic infections in students and their hormonal and immunological repercussions on physical development. Students of basic education of both sexes were evaluated. Parasitological stool tests were performed using the Hoffman and Kato-Katz methods. The students were divided into two groups: a control group (negative parasitological examination, N=25) and an infected group (positive parasitological test, N=25). Anthropometric variables (height, weight, and BMI), concentrations of hormones (melatonin and cortisol), cytokine/chemokine levels (IL-1ß, IL-6, IL-8, IL-10, IL-12, IL-17 and TNF-α) and physical performance (aerobic capacity, upper- and lower-limb muscle strength and abdominal performance) were evaluated. The prevalence of parasitic infection among the students was 7.98%. No anthropometric differences were observed among the groups. IL-2 and TNF-α levels were higher and IL-8 levels were lower in serum from students who were positive for parasitic infection. Serum from students who were positive for parasitic infection showed higher levels of melatonin than that from parasitenegative students. No differences were observed in cortisol levels. Students who were positive for parasitic infection presented greater lower-limb strength and lower abdominal performance than parasite-negative students. In the parasitic infection group, IL-12 was positively correlated with melatonin. In the parasitic infection group, IL-8 showed a positive correlation with aerobic capacity, while IL-17 and TNF-α showed a positive correlation with abdominal performance. These data suggest that parasitic infections determine the profile of inflammatory cytokines and that melatonin may be involved in the control of this process to minimize tissue damage. Additionally, students' difficulty in practising physical exercises can be an indication of enteroparasitic infection.

Prevalence of enteroparasitic infections and related hormonal and immunological repercussions that may compromise students’ physical performance

@#The aim of this study was to evaluate the prevalence of enteroparasitic infections in students and their hormonal and immunological repercussions on physical development. Students of basic education of both sexes were evaluated. Parasitological stool tests were performed using the Hoffman and Kato-Katz methods. The students were divided into two groups: a control group (negative parasitological examination, N=25) and an infected group (positive parasitological test, N=25). Anthropometric variables (height, weight, and BMI), concentrations of hormones (melatonin and cortisol), cytokine/chemokine levels (IL-1β, IL-6, IL-8, IL-10, IL-12, IL-17 and TNF-α) and physical performance (aerobic capacity, upper- and lower-limb muscle strength and abdominal performance) were evaluated. The prevalence of parasitic infection among the students was 7.98%. No anthropometric differences were observed among the groups. IL-2 and TNF-α levels were higher and IL-8 levels were lower in serum from students who were positive for parasitic infection. Serum from students who were positive for parasitic infection showed higher levels of melatonin than that from parasitenegative students. No differences were observed in cortisol levels. Students who were positive for parasitic infection presented greater lower-limb strength and lower abdominal performance than parasite-negative students. In the parasitic infection group, IL-12 was positively correlated with melatonin. In the parasitic infection group, IL-8 showed a positive correlation with aerobic capacity, while IL-17 and TNF-α showed a positive correlation with abdominal performance. These data suggest that parasitic infections determine the profile of inflammatory cytokines and that melatonin may be involved in the control of this process to minimize tissue damage. Additionally, students’ difficulty in practising physical exercises can be an indication of enteroparasitic infection.

GILP family: a stress-responsive group of plant proteins containing a LITAF motif.

Lipopolysaccharide-induced tumor necrosis factor-α (LITAF) is a membrane protein that is highly dependent on correct location to exert transcription factor activity and protein quality control. In humans, LITAF, PIG7 (p53-inducible gene 7), and SIMPLE (small integral membrane protein of the lysosome/late endosome) refer to the same gene, which acts as a tumor suppressor. Several studies have shown that the transcription factor activity and nuclear translocation of LITAF protein are critical for the induction of several immune cells via classical pathways. In plants, LITAF protein corresponds to the plasma membrane protein AtGILP (Arabidopsis thaliana GSH-induced LITAF domain protein). The conservation of LITAF proteins across species and their putative role is still unclear. In this study, we investigate the LITAF-containing proteins, which we call GILP proteins, in Viridiplantae. We identified a total of 59 genes in 46 species, whose gene copies range from one to three. Phylogenetic analysis showed that multiple copies were originated via block duplication posteriorly to monocot and eudicot separation. Analysis of the LITAF domain of GILP proteins allowed the identification of a putative domain signature in Viridiplantae, containing a CXXCX41HXCPXC motif. The subcellular location for the majority of GILP proteins was predicted to be in the plasma membrane, based on a transmembrane domain positioned within the LITAF domain. In silico analysis showed that the GILP genes are neither tissue-specific nor ubiquitously expressed, being responsive to stress conditions. Finally, investigation of the GILP protein network resulted in the identification of genes whose families are known to be involved with biotic and/or abiotic stress responses. Together, the expression modulation of GILP genes associated with their plasma membrane location suggests that they could act in the signaling of biotic/abiotic stress response in plants.

Maternal-Foetal Diabetes Modifies Neonatal Fc Receptor Expression on Human Leucocytes.

This study investigated the expression of the neonatal Fc receptor (FcRn) in maternal blood, cord blood and placental cells and determined IgG levels in maternal blood and cord blood from diabetic mothers. Peripheral blood, cord blood and placenta samples were collected from 26 mothers with normoglycaemia (non-diabetic, ND group) and 52 with hyperglycaemia (26 with mild gestational hyperglycaemia, MGH group, and 26 with type 2 diabetes mellitus, DM-2 group). Cells expressing CD19(+) and FcRn were identified by flow cytometry. Total IgG and its subclasses were quantified by ELISA. Maternal blood from DM-2 and cord blood from MGH exhibited a higher proportion of CD19(+) expression by B cells. DM-2 showed a lower proportion of CD19(+) cells in placenta. FcRn expression increased in cells from cord blood and placenta from MGH. Maternal blood, cord blood and placenta cells from DM-2 showed lower FcRn expression. Blood IgG levels were lower in DM-2, and cord blood IgG levels were higher in MGH. The highest levels of IgG4 were detected in the blood of hyperglycaemic mothers. The highest IgG3 and IgG4 levels in cord blood were detected in MGH, and the lowest IgG2 and IgG3 levels in DM-2. Maternal hyperglycaemia compromised placental transfer of IgG1, IgG3 and IgG4. The results suggest that regardless of hyperglycaemia degree, it decreases FcRn expression in placenta and blood cells and compromises the production and transfer of antibodies from maternal blood to newborns.

L-Arginine Modulates Intestinal Inflammation in Rats Submitted to Mesenteric Ischemia-Reperfusion Injury.

BACKGROUND: The goal of this study was to investigate whether exogenous offer of L-arginine (LARG) modulates the gene expression of intestinal dysfunction caused by ischemia and reperfusion. METHODS: Eighteen Wistar-EPM1 male rats (250-300 g) were anesthetized and subjected to laparotomy. The superior mesenteric vessels were exposed, and the rats were randomized into 3 groups (n = 6): the control group (CG), with no superior mesenteric artery interruption; the ischemia/reperfusion group (IRG), with 60 minutes of ischemia and 120 minutes of reperfusion and saline injections; and the L-arginine group (IRG + LARG), with L-arginine injected in the femoral vein 5 minutes before ischemia, 5 minutes after reperfusion, and after 55 minutes of reperfusion. The total RNA was extracted and purified from samples of the small intestine. The concentration of each total RNA sample was determined by using spectrophotometry. The first-strand complementary DNA (cDNA) was synthesized in equal amounts of cDNA and the Master Mix SYBR Green qPCR Mastermix (SABiosciences, a Qiagen Company, Frederick, Md). Amounts of cDNA and Master Mix SYBR Green qPCR Mastermix were distributed to each well of the polymerase chain reaction microarray plate containing the predispensed gene-specific primer sets for Bax and Bcl2. Each sample was evaluated in triplicate, and the Student t test was applied to validate the homogeneity of each gene expression reaction (P < .05). RESULTS: The gene expression of Bax in IRG (+1.48) was significantly higher than in IRG-LARG (+9.69); the expression of Bcl2L1 in IRG (+1.01) was significantly higher than IRG-LARG (+22.89). CONCLUSIONS: The apoptotic cell pathway of 2 protagonists showed that LARG improves the gene expression of anti-apoptotic Bcl2l1 (Bcl2-like 1) more than the pro-apoptotic Bax (Bcl2-associated X protein).

Period of Hyperbaric Oxygen Delivery Leads to Different Degrees of Hepatic Ischemia/Reperfusion Injury in Rats.

BACKGROUND: This study evaluated the morphology of the rat liver when hyperbaric oxygen (HBO) was used at various stages of ischemia and reperfusion. METHODS: Thirty-two male Wistar rats, subjected to 30 minutes of hepatic ischemia and 30 minutes of reperfusion, were randomly assigned as follows: GIR (n = 8), control without HBO; GHBO/I (n = 8), in which HBO was applied only during ischemia; GHBO/R (n = 8), HBO only during reperfusion; and GHBO/IR (n = 8), HBO during both ischemia and reperfusion. Feasibility scores of hepatocytes were determined by assessing 8 items related to liver injury. RESULTS: The histologic injury score of the hepatic specimens was significantly lower in the GHBO/I group (79.0 ± 0.1) compared with the GIR group (135.0 ± 0.1). HBO was not effective when applied during reperfusion (GHBO/R, 151.3 ± 0.1) or during the ischemia plus reperfusion period (GHBO/IR, 131.0 ± 0.1). The sum was significantly higher (P < .05) in HBO-treated animals during the reperfusion period (ie, in the GHBO/R group compared with any of the other groups). CONCLUSIONS: A favorable effect was obtained when HBO was administered early during ischemia. HBO given in later periods of reperfusion was associated with a more severe sum index percentage of liver damage.

Síndrome de bridas amnióticas. Relato de un caso de tratamiento quirúrgico y revisión de la literatura / Constriction ring syndrome. Case report of surgical treatment and review of literature

El síndrome de bridas amnióticas (SBA) abarca un amplio espectro de alteraciones congénitas. La fisiopatología de esta dolencia está relacionada con períodos críticos de la embriogénesis y la organogénesis. Se considera un error de la morfogénesis de tipo disruptivo. Diversos estudios intentan mediante diferentes teorías explicar la fisiopatología de esta entidad. El presente trabajo tiene como objetivo presentar el relato del tratamiento quirúrgico seguido en un paciente de 1 año y 9 meses de edad que padecía deformidad debida a SBA y de paso, hacer una revisión de las teorías etiopatogénicas conocidas sobre esta alteración congénita (AU)

The syndrome of amniotic brides (SAB) covers a wide spectrum of congenital changes. The pathophysiology of this disease is related there critical periods of embryogenesis and organogenesis. It is considered an error in the morphogenesis of such disruption. Many scholars try to explain theories in the pathophysiology of this disease. This work aims reports of surgical treatment of a 1 year and 9 months patient suffered deformation due to SAB, as well as a review of etiopathogenic theories (AU)

Mechanism of action of Trolox on duodenal contractility.

Trolox is a hydrophilic analogue of vitamin E. The aim of this work was to study the mechanism of action of Trolox on rabbit duodenal spontaneous motility and contractility. The duodenal contractility studies in vitro were carried out in an organ bath. Trolox (12 mM) reduced the amplitude and frequency of spontaneous contractions and the acetylcholine-induced contractions in the longitudinal and circular smooth muscle of rabbit duodenum. Quinine reverted the Trolox-induced (12 mM) reduction on the amplitude and frequency of spontaneous contractions in the longitudinal and circular muscle. Charibdotoxin and glibenclamide reverted only the amplitude of spontaneous contractions in circular muscle of the duodenum. The decrease of ACh-induced contractions evoked by Trolox 12 mM in the longitudinal and circular smooth muscle of the duodenum was antagonized by quinine in longitudinal and circular muscle and by Bay K8644, 1H-[1,2,4]oxadiazolo [4, 3-α]quinoxalin-1-one (ODQ) and nimesulide in circular muscle. We conclude that in the decrease of duodenal contractility induced by Trolox participate K(+) and Ca(2+) channels, adenylyl cyclase, guanylyl cyclase and cyclooxygenase-2.

Study of heparin in intestinal ischemia and reperfusion in rats: morphologic and functional evaluation.

To study whether treatment with heparin (HEP) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with HEP (100 U/kg intravenously) or saline solution (SS) before I (60 min), which was produced by occlusion of the superior mesenteric artery, and R (120 min). After I or I/R, we mounted 2-cm jejunal segment in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl, using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the I + HEP and the I/R + HEP groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS, but not in the I + HEP and the I/R + HEP cohorts. These results suggested that HEP attenuated intestinal dysfunction caused by I and I/R.

Effect of ischemic preconditioning on injuries caused by ischemia and reperfusion in rat intestine.

To study whether ischemic preconditioning (IPC) attenuated intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were underwent 60 minutes of I which was produced by occlusion of the superior mesenteric artery, and/or 120 minutes R. The IPC group had the I procedure previously stimulated for 5 minutes and the R for 10 minutes. IPC and sham groups were injected with saline solution (SS) via the femoral vein 5 minutes before the I and R, and for R. After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the IPC + I and the IPC + I/R groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the IPC groups. These results suggested that ischemic preconditioning attenuated intestinal dysfunction caused by I and I/R.

Study of L-arginine in intestinal lesions caused by ischemia-reperfusion in rats.

To examine whether treatment with L-arginine (ARG), a substrate of nitric oxide biosynthesis, attenuated intestinal dysfunction caused by ischemia (I) and reperfusion (R), we treated rats with ARG (100 mg/kg intravenously) or saline solution (SS) before 60 minutes of I produced by occlusion of the superior mesenteric artery and/or during 120 minutes of R. After I or I/R, we isolated 2-cm jejunal segments for mounting in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl with the use of a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Jejunal contractions were similar in the sham and I+ARG, but reduced in I+SS, I/R+SS, and I/R+ARG groups. Jejunal enteric nerves were damaged in I+SS, IR+SS, and IR+ARG, but not in the I+ARG group, suggesting that ARG attenuate intestinal dysfunctions due to I but not to R.

Effect of adenosine on injury caused by ischemia and reperfusion in rats: functional and morphologic study.

To study whether treatment with adenosine (ADO), an agonist of adenosine receptors, attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), we treated rats with ADO (15 mg/kg or saline solution (SS) intravenously before 60 minutes occlusion of the superior mesenteric artery (I) and/or 120 minutes after its release (R). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCI with the use of a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were reduced in I+SS and IR+SS but similar after treatment with ADO (I+ADO and IR+ADO groups). We concluded that rat jejunal enteric nerves were damaged in I+SS and IR+SS but not in the I+ADO and IR+ADO groups. These results suggested that ADO attenuated intestinal dysfunction due to I and R.

Atenolol to treat intestinal ischemia and reperfusion in rats.

To study whether treatment with the beta-blocker atenolol (AT) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with AT (1.5 mg · kg(-1), intravenously) or saline solution (SS) prior to I (60 minutes), which was produced by occlusion of the superior mesenteric artery, and/or R (120 minutes). After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy analysis. Compared to the sham group, jejunal contractions were similar in the I + AT and the I/R + AT groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the I + AT and the I/R + AT. These results suggest that AT may attenuate intestinal dysfunction caused by I and I/R.

Efeito do composto "mais vida" na ativação de macrófagos de ratos diabéticos / Effects of "mais vida", a commercial natural mix, on the activation of macrophages from diabetic rats

O objetivo deste trabalho foi avaliar a atividade funcional de macrófagos de ratos diabéticos, através da liberação do ânion superóxido, na presença do composto "mais vida". Os animais foram divididos em dois grupos, controle (N=20) e diabético (N=20). Avaliou-se a glicemia, massa corpórea e a liberação de superóxido pelos macrófagos de baço de ratos. O composto "mais vida" foi obtido através da mistura de extratos de sete plantas, sendo Orbignia martiana Rodr., Tabebuia avellanedae L.G., Arctium lappa L., Rosa centifolia L., Maytenus ilicifolia Mart., Vernonia condensata Baker e Thuja occidentalis L. Observou-se que glicemia foi maior no grupo diabético. A liberação espontânea do ânion superóxido pelos macrófagos foi menor no grupo diabético. O composto "mais vida", independente dos níveis glicêmicos, aumentou a liberação de superóxido dos macrófagos. Quando as células foram estimuladas pelos extratos vegetais isolados, também houve aumento na liberação do ânion superóxido pelos macrófagos em ambos os grupos. As maiores liberações de superóxido ocorreram quando os macrófagos foram estimulados pela Thuja occidentalis L., Rosa centifolia L., Tabebuia avellanedae L.G. e Maytenus ilicifolia Mart. Estes dados sugerem que a ativação de macrófagos pelo composto "mais vida" pode representar um mecanismo alternativo de defesa para infecções em indivíduos diabéticos.

This study investigated the effects of "mais vida", a commercial natural mix, on macrophages functional activity as evaluated by the superoxide release in diabetic rats. The animals were divided into two groups, control (N = 20) and diabetic (N = 20). This was achieved by determining blood glucose weight and the superoxide released by spleen macrophages. The "mais vida" mix was obtained by the combination of extracts from seven medicinal species, which were: Orbignia martiana Rodr., Tabebuia avellanedae L.G., Arctium lappa L., Rosa centifolia L., Maytenus ilicifolia Mart., Vernonia condensata Baker and Thuja occidentalis L. Blood glucose levels were significantly higher (p<0.05) in the diabetic group, as compared to blood glucose levels in the control group. Superoxide levels in macrophages isolated from normoglycemic rats were higher than those obtained from diabetic animals. The "mais vida" mix, independently of glycemic status, increased significantly the superoxide release in the macrophages. Each extract by itself also increased the superoxide release by phagocytes in the macrophages in both groups. The largest superoxide release occurred when the phagocytes were stimulated by Thuja occidentalis L., Rosa centifolia L., Tabebuia avellanedae L.G. and Maytenus ilicifolia Mart. In addition, the activation of macrophages by the "mais vida" mix may represent an additional protection mechanism for diabetic individuals against infections.

Shrinkage evaluation of heavyweight and lightweight polypropylene meshes in inguinal hernia repair: a randomized controlled trial.

BACKGROUND: One of the current complications in inguinal repair is shrinkage following the use of mesh. The selected mesh material, heavyweight (HWM) mesh or lightweight (LWM) mesh, is associated with the frequency of shrinkage. The aim of this study was to investigate shrinkage of these two types of mesh in a controlled trial of male inguinal hernia repair. METHODS: Thirty-two healthy men with primary unilateral inguinal hernias (Nyhus classification), who presented at São José Hospital of Criciúma, Brazil, underwent the Lichtenstein procedure. In total, 16 polypropylene HWM (105 g/m(2)) and 16 partially absorbable LWM (28 g/m(2)) were implanted into randomly selected patients. On post-operative days 1, 30, 60 and 90, the area of the mesh was evaluated by digital radiography. RESULTS: The study randomized 32 patients and analyzed 30 patients--15 for each type of mesh. At baseline, there were no differences between groups. There were significant differences between the two meshes when comparing the total area initially and on postoperative day 90 (P = 0.001). The HWM had significantly less area initial area, as compared with 90 days postoperatively (P = 0.04). CONCLUSION: Shrinkage was significantly higher for HWM, although the difference was not large.

Tratamiento quirúrgico de la falange distalbífida por traumatismo de mano en la infancia / Surgical treatment of distal bifid phalanx post of hand trauma in childhood

La extremidad distal de los dedos es la parte de la mano que más frecuentemente se lesiona. Las principales complicaciones que pueden derivar de ese tipo de lesiones traumáticas incluyen: infecciones, retracciones de la piel, deformidades óseas y amputaciones. El presente artículo tiene como objetivo presentar el tratamiento quirúrgico seguido en un pacientes de 16 años que sufrió traumatismo sobre la falange distal del segundo dedo de la mano derecha a los 2 años de edad, a consecuencia del cual se produjo deformidad ósea y falangebífida asociada a retracción de la piel en el punto dela lesión (AU)

The distal extremity of the fingers of the hand is the most frequently injured. The main complications that can occur as a result of these traumatic injuries include: infections, retraction of the skin, bone deformities and amputations. This article aims to report the surgical treatment of a 16 years old patient who suffered a trauma in the distal phalanx of the second finger of right hand when he was 2 years old, resulting in bone deformity and distal phalanx bifid associated with retraction of the skin at the site where the injury occurred (AU)

Role of potassium channels in rabbit intestinal motility disorders induced by 2, 2'-azobis (2-amidinopropane) dihydrochloride (AAPH).

Oxidative stress appears to play a role in the pathogenesis of several inflammatory gastrointestinal diseases. Changes in intestinal motility have been reported in different models of intestinal inflammation. The initiating factor of altered motility could be an alteration of gut redox status. The aim of this study was to investigate the effect of oxidative stress evoked by 2, 2'-azobis (2-amidinopropane) dihydrochloride (AAPH) on the intestinal motility of rabbit duodenum and the possible contribution of different K(+) channels in mediating this response. Whole thickness segments of rabbit duodenum were suspended in the direction of the longitudinal or circular smooth muscle fibres in an organ bath to study the effects of AAPH alone, or in the presence of different K(+) channel blockers on the amplitude, frequency and tone of spontaneous contractions. In circular muscle, AAPH 20 mM induced a reduction of the amplitude, the frequency and tone of the spontaneous contractions. In longitudinal muscle, AAPH 10 mM induced a reduction of the amplitude and tone of the spontaneous contractions. The reduction of the amplitude and tone induced by AAPH was reverted by BaCl2 (1 mM) and TEA (5 mM). Charybdotoxin (100 nM) and iberiotoxin (100 nM) only reverted the reduction of the tone induced by AAPH. In conclusion, our results show that the peroxyl radicals released by AAPH reduced the amplitude and the tone of the spontaneous contractions of the longitudinal smooth muscle from rabbit small intestine. Inward rectifier and intermediate and large-conductance Ca(2+)-activated K(+) channels could be involved in these effects.

Effects of L-nitro-arginine methyl ester, an inhibitor of nitric oxide biosynthesis, on intestinal ischemia/reperfusion injury in rabbits.

To study whether treatment with L-nitro-arginine methyl ester (L-NAME), an inhibitor of nitric oxide biosynthesis, attenuates intestinal dysfunction caused by ischemia (I) and/or reperfusion (R), rabbits were treated with L-NAME (15 mgxkg(-1), intervenously) or saline olution (SS) prior to I (60 minutes) induced by occlusion of superior mesenteric artery and/or R (120 minutes). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCI using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared with a sham group, the jejunal contractions were similar in the I/R + L-NAME, but reduced in I + SS, I/R + SS, and I + L-NAME groups. The jejunal enteric nerves were damaged in the I + SS, I/R + SS, and I + L-NAME cohorts, but not among the I/R + L-NAME cohort. These results suggested that L-NAME attenuated intestinal dysfunction caused by R but not by I.