This study was conducted to investigate the effects of oxytocin (OT) on visceral hypersensitivity/pain and mast cell degranulation and the underlying mechanisms. We found that oxytocin receptor (OTR) was expressed in colonic mast cells in humans and rats, as well as in human mast cell line-1 (HMC-1), rat basophilic leukemia cell line (RBL-2H3) and mouse mastocytoma cell line (P815). OT decreased 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced visceral hypersensitivity, colonic mast cell degranulation and histamine release after mast cell degranulation in rats. Also, OT attenuated the compound 48/80 (C48/80)-evoked histamine release in P815 cells and inward currents, responsible for the mast cell degranulation, in HMC-1, RBL-2H3 and P815 cells. Moreover, these protective effects of OT against visceral hypersensitivity and mast cell degranulation were eliminated by coadministration of OTR antagonist atosiban or a nonselective inhibitor of nitric oxide synthase (NOS), NG-Methyl-L-arginine acetate salt (L-NMMA). Notably, OT evoked a concentration-dependent increase of intracellular Ca 2+ in HMC-1, RBL-2H3 and P815 cells, which was responsible for the activation of neuronal NOS (NOS1) and endothelial NOS (NOS3). Our findings strongly suggest that OT might exert the antinociception on colonic hypersensitivity through inhibition of mast cell degranulation via Ca 2+ -NOS pathway.

Abstract Objective: Activation of mitochondrial (MitoKATP) channels was found to protect against anoxic and chemical stress in brain. This present study sought to investigate the ability of diazoxide and cyclosporin A to antagonize cytotoxicity induced by beta-amyloid peptide (A-beta1-42) in cultured rat primary basal forebrain cholinergic neurons. Methods: Cytotoxicity was induced by A-beta1-42 (2 μM) in the presence of either diazoxide (500 μM), a selective opener of the mitochondrial ATP-sensitive potassium channel (MitoKATP), or cyclosporin A (20 μM), an inhibitor of the mitochondrial permeability transition pore (MTP), or the combination of both the reagents. We determined cell morphology and cell viability using MTT assay and expression levels of anti-apoptotic protein (Bcl-2), pro-apoptotic proteins (Bax, cytochrome C, caspase-3 and cleaved caspase-3) using Western blotting at 24 hours and 72 hours. Results: Cell viability decreased markedly after exposure to A-beta1-42 for 72 hours with a decrease in the expression of Bcl-2 protein and cytochrome C and an increase in the caspase-3 and cleaved caspase-3 levels. Both diazoxide and cyclosporin A exerted significant protective effects on cell viability by ameliorating the decrease in Bcl-2 and the increase in cytochrome c and caspase-3 activity induced by A-beta1-42. The combination of both the reagents had a greater protective effect than either one alone. Conclusions: The present research demonstrates that activation of MitoKATP channels independently or in combination with inhibitors of the MTP can elicit a protective effect against primary cholinergic neuron cytotoxicity induced by A-beta1-42. These findings suggest new mitochondrial targets for the development of therapeutic agents against A-beta-induced cytotoxicity.

Enhanced neurogenesis in the dentate gyrus of the hippocampus following seizure activity, especially status epilepticus, is associated with ectopic residence and aberrant integration of newborn granule cells. Hilar ectopic granule cells may be detrimental to the stability of dentate circuitry by means of their electrophysiological properties and synaptic connectivity. We hypothesized that status epilepticus also increases ectopic granule cells in the molecular layer. Status epilepticus was induced in male Sprague-Dawley rats by intraperitoneal injection of pilocarpine. Immunostaining showed that many doublecortin-positive cells were present in the molecular layer and the hilus 7 days after the induction of status epilepticus. At least 10 weeks after status epilepticus, the estimated number of cells positive for both prospero homeobox protein 1 and neuron-specific nuclear protein in the hilus was significantly increased. A similar trend was also found in the molecular layer. These findings indicate that status epilepticus can increase the numbers of mature and ectopic newborn granule cells in the molecular layer.

Background and PurposeH2S induces vasodilatation by opening KATP channels but it may also affect other ion channels. The aim of this study was to investigate the effect of H2S on intestinal motility in rats and its underlying mechanism.Experimental ApproachThe tension of intestinal muscle strips, afferent firing of intestinal mesenteric nerves, length of duodenal smooth muscle cells and whole‐cell membrane potential of dorsal root ganglion (DRG) neurons were monitored. H2S‐producing enzymes were located by immunofluorescence staining.Key resultsNaHS exerted early transient excitation and late long‐lasting inhibition on the intestinal contraction. The excitation was attenuated by TRPV1 antagonists capsazepine, A784168, SB‐366791 and NK1 receptor antagonist L703606, while the inhibition was attenuated by glibenclamide. NaHS increased duodenal afferent nerve firing and depolarized DRG neurons. These effects were reduced by capsazepine and A784168. NaHS relaxed isolated duodenal smooth muscle cells. The KATP channels were expressed in smooth muscle cells. Cystathionine β‐synthase and cystathionine γ‐lyase were expressed in rat duodenal myenteric neurons. L‐cysteine and S‐adenosyl‐L‐methionine increased the contraction of duodenal muscle strips, an effect attenuated by capsazepine and L703606.Conclusions and ImplicationsNaHS induces biphasic effects on intestinal motility in rats while endogenous H2S only exerts an excitatory effect. This transient excitatory effect might be mediated by activation of TRPV1 channels in sensory nerve terminals with the consequent release of substance P. The long‐lasting inhibitory effect might be mediated by activation of KATP channels in the smooth muscle cells. These findings reveal a novel mechanism for the excitatory effect of H2S on gastrointestinal motility.

The mechanism underlying visceral pain is still largely unclear. Recently, much attention has focused on a potential modulatory role of brain-derived neurotrophic factor (BDNF) in visceral pain. In the present study, we investigated the expression of BDNF in dorsal root ganglia (DRG) primary sensory neurons and its role in a colorectal distention (CRD)-induced model of visceral pain. Results obtained from enzyme-linked immunosorbant assay (ELISA) revealed that BDNF protein was upregulated after CRD. An abdominal withdrawal reflex (AWR) assay confirmed that BDNF played an antinociceptive role in this model. Application of BDNF directly to DRG neurons decreased their hypersensitivity when evoked by CRD. Pretreatment with k252a partially blocked the effect of BDNF. These findings suggest that BDNF might be a novel analgesic agent for the treatment of visceral pain. (c) 2012 Wiley Periodicals, Inc.

J. Neurochem. (2012) 121, 516–525.AbstractOxytocin (OT) is clinically important in gut motility and constitutively reduces duodenum contractility. Intrinsic primary afferent neurons (IPANs), whose physiological classification is as AH cells, are the 1st neurons of the peristaltic reflex pathway. We set out to investigate if this inhibitory effect is mediated by IPANs and to identify the ion channel(s) and intracellular signal transduction pathway that are involved in this effect. Myenteric neurons were isolated from the longitudinal muscle myenteric plexus (LMMP) preparation of rat duodenum and cultured for 16–24 h before electrophysiological recording in whole cell mode and AH cells identified by their electrophysiological characteristics. The cytoplasmic Ca2+ concentration ([Ca2+]i) of isolated neurons was measured using calcium imaging. The concentration of IP3 in the LMMP and the OT secreted from the LMMP were measured using ELISA. The oxytocin receptor (OTR) and large‐conductance calcium‐activated potassium (BKCa) channels, as well as the expression of OT and the IPAN marker calbindin 28 K, on the myenteric plexus neurons were localized using double‐immunostaining techniques. We found that administration of OT (10−7 to 10−5 M) dose dependently hyperpolarized the resting membrane potential and increased the total outward current. The OTR antagonist atosiban or the BKCa channel blocker iberiotoxin (IbTX) blocked the effects of OT suggesting that the increased outward current resulted from BKCa channel opening. OTR and the BKCaα subunit were co‐expressed on a subset of myenteric neurons at the LMMP. NS1619 (10−5 M, a BKCa channel activator) increased the outward current similar to the effect of OT. OT administration also increased [Ca2+]i and the OT‐evoked outward current was significantly attenuated by thapsigargin (10−6 M) or CdCl2. The effect of OT on the BKCa current was also blocked by pre‐treatment with the IP3 receptor antagonist 2‐APB (10−4 M) or the PLC inhibitor U73122 (10−5 M). OT (10−6 M) also increased the IP3 concentration within the LMMP. Both of the spontaneous and KCl‐induced secretion of OT was enhanced by atosiban. Most of OT‐immunoreactive cells are also immunoreactive for calbindin 28 K. In summary, we concluded that OT hyperpolarized myenteric IPANs by activating BKCa channels via the OTR‐PLC‐IP3‐Ca2+ signal pathway. OT might modulate IPANs mediated ENS reflex by an autocrine and negative feedback manner.

Objective: To interview the role of CGRP to hepatic microcirculation in acute liver injury induced by coneanavalin A(Con A). Methods: Sixty Kunming rats were divided into three groups randomly(n=20), acute liver injury was established by injection with 20 mg/kg Con A through the tail vein. A saline control group was established by injection with saline. In CGRP-administered group, CGRP was given to rats 30 min before Con A injected. Ten mice in each group were used to observe the average liver blood flow volume and concentration by laser-doppler flow-instrument, and the other ten rats were observed the hepatic microcirculation velocity in vivo by an inverted microscope. Liver damage was assessed by histological evaluation after the rat had been killed. Results: Compared to the injury group, the average liver blood flow volume and velocity were significantly increased in CGRP-administered group, meanwhile, the pathological injury was markedly alleviated, whereas the blood concentration was almost the same. Conclusion: CGRP can decrease the dysfunction of hepatic microcirculation by means of improving the tissue perfusion, and alleviate the pathological damage during acute liver injury.

3'-Methoxypuerarin (3'-MOP) is an isoflavone extracted from radix puerariae. The aim of this study was to investigate the role and the mechanism of 3'-MOP in the protection of hippocampal neurons against cerebral ischemia/reperfusion (I/R) injury in rats. I/R injury was induced by a modified four-vessel occlusion model. Rats were randomly divided into an I/R group, an I/R + 3'-MOP group and a control group. Histological changes in the neurons of the hippocampal CA1 region were observed with hematoxylin and eosine (H&E) staining. The apoptotic neurons in the hippocampal CA1 area were counted with the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. The results showed that compared with the I/R group, 3'-MOP increased the number of surviving neurons in the hippocampal CA1 region (P < 0.001) and markedly reduced the number of apoptotic pyramidal neurons (P < 0.001) after I/R injury. In conclusion, 3'-MOP can protect hippocampal neurons against I/R injury by inhibiting apoptosis.

Objective To investigate the effects and mechanism of Pioglitazone on traumatic brain injury(TBI)-induced deficits of learning memory ability and damage of hippocampus neurons in rats.Methods Left lobus parietalis damage models were made in 24 SD rats which were randomly divided into four groups: the Sham group,the Vehicle group,the Pio group and the Pio +Ant group.A Morris water maze was used to observe the changes of their learning memory behavior.On the 15th day the rats were sacrificed to take brain coronal frozen sections.NeuN,OX-42 and GFAP immunohistochemistry were used to stain neurons,microglia and astrocyte,and their numbers in hippocampus CA1,CA2 and CA3 areas were counted.Results The Morris water maze test indicated that compared with the Sham group the learning ability of the Vehicle group significantly dropped which was manifested as extension of latency(P0.01)and distance(P0.01);the number of neurons was decreased(P0.01) and NeuN stain was light;and the numbers of microglias(P0.01) and astrocytes(P0.01) were increased.The Pio group had shorter latency and distance than the Vehicle group(both P0.05);the number of surviving neurons was increased(P0.05) and expression of NeuN wasstrengthened;and the numbers of microglias(P0.05) and astrocytes were decreased(P0.05).Conclusion According to the PPARγ pathway,Pioglitazone can alleviate the TBI-induced inflammatory reaction in the hippocampus and plays an important role in neuron protection and learning memory ability.

The aim of this study was to determine changes of PAR-2 expression in distal colon and the sensitivity of colonic muscle to SLIGRL-NH2, the PAR-2-activating peptide (PAR-2-AP) following bacillary dysentery. Shigella flexneri was administrated intragastrically in healthy male rats to induce bacillary dysentery. The effect of SLIGRL-NH2 on the motility of colonic muscle strips were examined. The expression of PAR-2 was determined by immunohistochemistry and Western blotting. Intragastric administration of S. flexneri induced acute inflammation at the mucosa of the distal colon at 4–11days, and the inflammation disappeared 18days later. PAR-2-AP-induced TTX insensitive relaxation of the colonic muscle strips. This inhibitory effect on colonic circular muscle strips was reduced on days 11–35, but the carbachol-induced contraction did not change. PAR-2 was located at the colon smooth muscles cells and myenteric nerve plexus. The amount of PAR-2 expression in distal colon was down regulated on days 11–35. These data indicated that bacillary dysentery exerted a long-term downregulation on the expression of PAR-2 in distal colon. This might be the reason of the low sensitivity of the colon circular muscle strips to the PAR-2-AP-induced relaxation following intragastric administration of S. flexneri.

Based on discrete density evolution (DDE), we develop closed form expressions to predict the error floor of LDGM codes. The first, rougher, approximation is obtained by assuming perfect message passing between systematic and parity bit nodes in DDE. The second, finer, expression leads to a more involved formulation. While the rougher approximation matches well to simulation results and DDE analysis for high signal to noise ratio (additive white Gaussian noise, AWGN, channel) or low crossover probability (binary symmetric channel, BSC), the finer approximation shows a good match for a wider range in the channel quality.

BACKGROUND:Arginine vasopressin (AVP) is widely used in the treatment of critical diseases with hypotension, but the reports about its effect on gastrointestinal motility are controversial. The purpose of this study was to characterize the role of AVP in the regulation of colonic motility and the underlying mechanism. METHODS:The contraction of the circular muscle strips (CM) of colon in male rats was monitored by a polygraph. The expressions of cytoplasmic inducible nitric oxide synthase (iNOS), I-κB, and the nuclear P65 in proximal colon were measured by Western blot. The V(1) receptors (V(1) Rs) and iNOS were localized by immunohistochemistry. The content of nitric oxide (NO) in the colon was measured by Griess reagent at the absorbance of 560 nm. KEY RESULTS:Arginine vasopressin (10(-10) -10(-6) mol L(-1)) caused a concentration-dependent inhibition on CM contraction. Pretreatment with one of the following chemicals, including V-1880 (10(-7) mol L(-1)), TTX (10(-5) mol L(-1)), L-NAME (10(-4) mol L(-1)), NPLA (10(-7) mol L(-1)), SMT (10(-3) mol L(-1)), and PDTC (10(-3) mol L(-1)), attenuated the inhibitory effect of AVP on CM contraction. Arginine vasopressin increased the expression of iNOS and the content of NO in proximal colon. These effects were attenuated by pretreatment with PDTC (10(-3) mol L(-1)). Following AVP administration, the amount of cytoplasmic I-κB decreased, but that of nuclear P65 increased. Double immunofluorescence labeling revealed that V(1) Rs and iNOS were co-localized on the cells of myenteric plexus in proximal colon. CONCLUSIONS & INFERENCES:Arginine vasopressin inhibited the contraction of CM in proximal colon. This effect was mediated by NO produced from NF-κB-iNOS pathway and neuronal NOS activation in myenteric plexus.

Mechanisms underlying delayed selective neuronal death after global cerebral ischemia remain to be clarified. Here, we report a critical role for tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in the pathogenesis of cerebral ischemia. C57BL/6j mice were subjected to transient global brain ischemia. RT-PCR and immunohistochemistry showed that the expression of TRAIL and DR5 was upregulated following transient ischemia–reperfusion. Dual immunofluorescence analysis indicated that TRAIL expression was significantly more pronounced in astrocytes and activated microglia/macrophages, whereas DR5 expression was more pronounced in neurons, which had a good correlation with the distribution of apoptotic cells. Treatment with soluble DR5 reduced ischemic cell death after transient global ischemia through blocking the interaction of endogenous TRAIL with DR5. These results indicate that TRAIL plays a deleterious role in the pathogenesis of delayed neuronal damage after global cerebral ischemia and inhibition of TRAIL function in the brain may represent a novel neuroprotective strategy to treat ischemic stroke.

We introduce the use of Discrete Density Evolution (DDE) to optimize LDGM-based quantum codes. These are Calderbank-Shor-Steane (CSS) codes based on the generator and parity-check matrices of an LDGM code, which is designed with a specific structure inspired in the parallel concatenation of LDGM codes. The proposed codes allow greater flexibility and are easier to design than existing sparse-graph CSS quantum codes, while leading to better performance.

Objective To establish Alzheimer disease(AD) models in Wistar rats using β-amyloid1-42(Aβ1-42) and study the effect of diazoxide on the change of apoptotic factors and the ethology of rat AD models.Methods Aβ1-42 was injected into the bilateral ventricles of all the rats,and two weeks later the AD models were established.Diazoxide was injected into some rats at the same time.Y maze electric stimulation was used to evaluate the capability of study and memory of the rats,and protein electrophoresis was used to detect expressions of Bcl-2 and Caspase-3 in the cortical layer and hippocampus of the rats.Results The capability of study and memory decreased expression of Bcl-2 decreased and expression of Caspase-3 increased in the rats injected with Aβ1-42 compared with the normal rats and those injected with NS(P 0.05).The capability of study and memory increased expression of Bcl-2 increased and expres-sion of Caspase-3 decreased in the rats injected with Aβ1-42 and diazoxide compared with the rats injected with Aβ1-42 a-lone(P 0.05).Conclusions The AD models were established by the injection of Aβ1-42 into the bilateral ventricles of the rats.Diazoxide can improve the capability of study and memory,increase Bcl-2 expression and decrease Caspase-3 expression.It is likely that diazoxide can resist neurons apoptosis induced by Aβ1-42.

The aim of the present study was to investigate the effect of oxytocin (OT) on duodenum motility in rats and the possibility that cholecystokinin (CCK) was involved in this process. The isometric contraction of longitudinal muscle strips of duodenum was monitored by polygraph. ELISA was used to measure the concentration of CCK and OT in duodenum. CCK mRNA was assayed by RT-PCR. Oxytocin receptor (OTR) and CCK in duodenum were located by immunohistochemistry and immunofluorescence staining. OT (10−5 and 10−6 M) inhibited the spontaneous contraction of the muscle strips. On the contrary, atosiban (OT receptor antagonist), lorglumide (CCK1 receptor antagonist), and tetrodotoxin (TTX, blocker of voltage-dependent Na+ channel on nerve fiber) excited the contraction. The inhibitory effect of OT on duodenal motility was reversed by pretreatment of atosiban, lorglumide, or TTX. Exogenous OT did not influence the expression of OT mRNA in duodenum but increased the concentration of CCK in the culture medium of the cells isolated from longitudinal muscle myenteric plexus. The OTR and CCK were co-expressed in the neurons of the myenteric plexus in duodenum. We concluded that OT inhibited the contraction of the LD spontaneous contraction of rats in vitro. This effect was mediated by the CCK released from the neurons of the myenteric plexus in duodenum.

The purpose of this study was to localize vasopressin (VP) V-1a receptor in stomach and to characterize the role of VP in the regulation of gastric motility in rats. Double staining was used to locate the V,a receptor in the gastric body of the rat The contraction of the circular muscle strips of gastric body was monitored by a polygraph. V-1a receptor was expressed on the neurons of myenteric plexus of the gastric body. VP (10(-10)-10(-6) M) caused a concentration-dependent contractile effect on the circular muscle strips of gastric body in vitro. V-1880 ([deamino-Pen(1), O-Me-Tyr(2), Arg(8)]-Vasopressin, 10(-7) M), a V-1 receptor antagonist, inhibited the spontaneous contraction of the strips. Tetradotoxin (TTY, 10(-6) M) and V-1880 (10(-7) M) abolished the excitatory effect of VP Atropine (10-6 M) partially inhibited VP-induced excitatory effect on the muscle strips but hexamethonium (10(-4) M) did not influence it These results suggest that V-1a receptor was expressed on the neurons of myenteric nerves. The cholinergic nerve was involved in the excitatory effect of VP on the contraction of gastric body. (c) 2009 Elsevier B.V. All rights reserved.

Action research is advocated as a tool for teachers' Professional development. This study is to examine whether action research will help teacher candidates gain insight into inquiring teaching and increase their teaching self-efficacy beliefs. Result shows that there is a closely correlation between research-based teaching and high teaching self-efficacy, and that action research inserts strong impact on teacher candidates' self-efficacy growth.

Objective To investigate the effects of diazoxide(ATP-sensitive potassium channel opener) and cyclosporine A and their combination on apoptosis induced by beta-Amyloid protein(Aβ1-42) on cultured primitive rat basal forebrain cholinergic neurons.Methods The cell apoptosis model was induced by Aβ1-42(2 μmmol/L),and then 500 μmol/L diazoxide,20 μmol/L cyclosporine A and their combination were used to interfere with it.Cell morphology was observed by an inverted microscope,changes of cell apoptosis were determined by MTT,and expressions of target proteins(bcl-2,bax,cytochrome C,caspasce-3 and Cleaved Caspase-3) were determined by Western blot when the neurons were interfered with by the drugs for different times(24,72 h).Results ① Being exposed to Aβ1-42 for 72 h,cell activity remarkably decreased(P0.001),expression of Bcl-2 decreased(P0.01) and expressions of cytochrome C,caspasce-3 and Cleaved Caspase3 increased(P0.01,P0.001,P0.01).Expression of Bax had no change but the value of Bcl-2/Bax decreased(P0.01).② Expression of Bcl-2 increased when the cell apoptosis model was exposed to diazoxide,cyclosporine A and their combination for 24 h(P0.05,P0.01,P0.01).When the cell apoptosis model was exposed to diazoxide,cyclosporine A and their combination for 72 h, expression of Bcl-2 obviously increased(P0.05,P0.01,P0.001), expressions of Cytochrome C,Caspasce-3 and Cleaved Caspase-3 decreased(P0.05,P0.01,P0.001),and cell activity increased(P0.01,P0.001).Conclusion Being exposed to Aβ1-42 for 72 h,neuron apoptosis occurs.Diazoxide and cyclosporine A and their combination could protect neurons from apoptosis induced by Aβ1-42.