The antinociception of oxytocin on colonic hypersensitivity in rats was mediated by inhibition of mast cell degranulation via Ca(2+)-NOS pathway.

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.

Chloroquine impairs visual transduction via modulation of acid sensing ion channel 1a.

Acid-sensing ion channels (ASICs) are extracellular pH sensors activated by protons, which influence retinal activity and phototransduction. Among all ASICs, ASIC1a is abundantly expressed in the retina and involved in normal retinal activity. Chloroquine, which has been used in the treatment of malaria, rheumatoid arthritis and systemic lupus erythematosus, has been shown to be toxic to the retina.

H2 S modulates duodenal motility in male rats via activating TRPV1 and K(ATP) channels.

Background And Purpose: H2 S 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 H2 S on intestinal motility in rats and its underlying mechanism.

Experimental Approach: The 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.

Diazoxide and cyclosporin A protect primary cholinergic neurons against beta-amyloid (1-42)-induced cytotoxicity.

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.

Status epilepticus increases mature granule cells in the molecular layer of the dentate gyrus in rats.

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.

Brain-derived neurotrophic factor exerts antinociceptive effects by reducing excitability of colon-projecting dorsal root ganglion neurons in the colorectal distention-evoked visceral pain model.

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.

Oxytocin hyperpolarizes cultured duodenum myenteric intrinsic primary afferent neurons by opening BK(Ca) channels through IP₃ pathway.

Oxytocin (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.

CCK mediated the inhibitory effect of oxytocin on the contraction of longitudinal muscle strips of duodenum in male rats.

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.

Protection by 3'-methoxypuerarin of rat hippocampal neurons against ischemia/reperfusion 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.

Blocking TRAIL-DR5 signaling with soluble DR5 reduces delayed neuronal damage after transient global cerebral ischemia.

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.

Long-term downregulation of protease-activated receptor-2 expression in distal colon in rats following bacillary dysentery.

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.

V1 receptor in ENS mediates the excitatory effect of vasopressin on circular muscle strips of gastric body in vitro in rats.

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(1a) receptor in the gastric body of the rat. The contraction of the circular muscle strips of gastric body was monitored by a polygraph.

Diazoxide reverses the enhanced expression of KATP subunits in cholinergic neurons caused by exposure to Aβ₁₋₄₂.

The ATP-sensitive potassium channel (KATP) play a crucial role in coupling metabolic energy to the cell membrane potential, β-amyloid peptide (Aβ) neurotoxicity has been associated with cellular oxidative stress and metabolic impairment. Whether there is an interaction between KATP and Aβ or not? The expression of KATP subunits was to be investigated after the cultured primary rat basal forebrain cholinergic neurons being exposed to Aβ₁₋₄₂. The subunits of KATP: Kir6.

Effects of Abeta1-42 on the subunits of KATP expression in cultured primary rat basal forebrain neurons.

ATP-sensitive potassium channels (KATP) play a crucial role in coupling metabolic energy to the membrane potential of cells, thereby functioning as cellular "metabolic sensors." Recent evidence has showed a connection between the amyloid neurotoxic cascade and metabolic impairment. With regard to their neuroprotection in other neuronal preparations, KATP channels may mediate a potential neuroprotective role in Alzheimer's disease (AD).

Inhibition of caspase-9 activation and apoptosis is involved in ischemic preconditioning-induced neuroprotection in rat brain.

Objectives: Cerebral ischemic pre-conditioning (IPC) is capable of protecting hippocampal neurons from ischemia/reperfusion (I/R) injury. In the current study, we investigated the role of activated caspase-9 in the protective process induced by IPC and related it to cytochrome c release and apoptosis.

Methods: I/R injury was induced by a four-vessel occlusion model in Wistar rats which were randomly divided into ischemia/reperfusion group (I/R), ischemic pre-conditioning + I/R group (IPC + I/R) and control group.

Ghrelin reduces injury of hippocampal neurons in a rat model of cerebral ischemia/reperfusion.

Ghrelin, an acyl-peptide gastric hormone and an endogenous ligand for growth hormone secretagogue (GHS) receptor 1a (GHS-R 1a) exerts multiple functions. It has been reported that synthetic GHS-hexarelin reduces injury of cerebral cortex and hippocampus after brain hypoxia-ischemia in neonatal rats. However, the effect of ghrelin in tolerance of the brain tissues to cerebral ischemia/reperfusion (I/R) injury has not been studied.

Sexual differences of the inhibitory effect of ethanol on gastrointestinal motility: in vivo and in vitro studies.

Female brain is more sensitive to the acute exposure of ethanol. This study aimed to investigate the sexual difference of the ethanol-induced inhibition of gastrointestinal motility. Wistar rats were fasted and allowed drinking water only 12 - 18 h before the experiments.

[Caspase-3 plays a required role in PC12 cell apoptotic death induced by roscovitine].

Roscovitine is a specific inhibitor of cyclin-dependent kinases (cdks) cdc2/cyclin B, cdk2/cyclin A, cdk2/cyclin E and cdk5/p35. The studies on the enzyme inhibitory properties and cellular effects of roscovitine revealed that it arrests cells in G(2)/M and G(1)/S phase, inhibits the proliferation of mammalian cells and induces cell death. However, the characteristics of cell death and exact mechanism by which this cdk inhibitor kills transformed cells are unknown.

Arecoline excites the colonic smooth muscle motility via M3 receptor in rabbits.

Arecoline is an effective component of areca (betel nuts, a Chinese medicine named pinang or binglang). The purpose of this study was to investigate the effect of arecoline on the motility of distal colon in rabbits and its mechanisms involved. Strips of colonic smooth muscle were suspended in organ baths containing Krebs solution, and their isometric contractions were examined.

Effect of oxytocin on contraction of rabbit proximal colon in vitro.

Aim: To investigate the effects of oxytocin (OT) on isolated rabbit proximal colon and its mechanism.

Methods: Both longitudinal muscle (LM) and circular muscle (CM) were suspended in a tissue chamber containing 5 mL Krebs solution (37 degrees ), bubbled continuously with 950 mL x L(-1) O(2) and 50 mL x L(-1) CO(2). Isometric spontaneous contractile responses to oxytocin or other drugs were recorded in circular and longitudinal muscle strips.

Effects of octreotide on gallbladder pressure and myoelectric activity of Oddi sphincter in rabbits.

AIM:To observe the effect of octreotide (OT) and somatostatin (SS) on gallbladder pressure and myoelectric activity of SO in rabbits.METHODS:Male rabbits fasted for 15h-18h and anesthetized with urethane. The mean gallbladder pressure (GP) and myoelectric activity of SO were simutaneously measured with a frog bladder connected to a transducer and a pair of copper electrodes.

TRH microinjection into DVC enhances motility of rabbits gallbladder via vagus nerve.

AIM:To investigate the effects of TRH in DVC on motility of the gallbladder in rabbits.METHODS:fter fasted for 15h-18h, rabbits were anesthetized with urethane (1.0g/kg).