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Pig Ileum (pig + ileum)
Kinds of Pig Ileum Selected AbstractsTwo tachykinin-like peptides from skin secretions of Danio rerioJOURNAL OF PEPTIDE SCIENCE, Issue 2 2010Xuhua Mi Abstract Tachykinin perform multiple physiological functions such as smoothing muscle contraction, vasodilation, inflammation, the processing of nerve signal, neuroprotection and neurodegeneration. Two novel tachykinin-like peptides named tachykinin-DR1 and -DR2 were identified from skin secretions of Danio rerio in current work. Their amino acid sequences were determined as SKSQHFHGLM-NH2 and NKGEIFVGLM-NH2, respectively. They share a conserved FXGLM-NH2C -terminal consensus motif. By cDNA cloning, the precursor encoding both tachykinin-DR1 and -DR2 was screened from the skin cDNA library of D. rerio. Tachykinin-DR1 and -DR2 share the same precursor, which is composed of 108 amino acid (aa) residues. Regarding the biological activity, tachykinin-DRs could induce the contraction of isolated strips of guinea pig ileum just like other tackykinins. To our best knowledge, this is the first report of tachykinin from fish skin. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd. [source] Highly potent side-chain to side-chain cyclized enkephalin analogues containing a carbonyl bridge: synthesis, biology and conformationJOURNAL OF PEPTIDE SCIENCE, Issue 3 2001Danuta Pawlak Abstract Six novel cyclic enkephalin analogues have been synthesized. Cyclization of the linear peptides containing basic amino acid residues in position 2 and 5 was achieved by treatment with bis(4-nitrophenyl)carbonate. It was found that some of the compounds exibit unusually high µ -opioid activity in the guinea pig ileum (GPI) assay. The 18-membered analogue cyclo(N,,N,, -carbonyl-,,-Lys2,Dap5)enkephalinamide turned out to be one of the most potent µ-agonists reported so far. NMR spectra of the peptides were recorded and structural parameters were determined. The conformational space was exhaustively examined for each of them using the electrostatically driven Monte Carlo method. Each peptide was finally described as an ensemble of conformations. A model of the bioactive conformation of this class of opioid peptides was proposed. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd. [source] Spasmolytic and antidiarrhoeal properties of the Yucatec Mayan medicinal plant Casimiroa tetrameriaJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2005Michael Heinrich The Maya of the Yucatán peninsula commonly use the leaves of Casimiroa tetrameria for treating gastrointestinal disorders, notably diarrhoea and dysentery, as well as gastrointestinal cramps. The phytochemical investigation resulted in the isolation of 13 compounds: eight polymethoxylated flavonoids (two as minor components with a main constituent), four flavonoid glycosides and one furanocoumarin. In this study we used two well-established models in order to assess the gastrointestinal effects of C. tetrameria extracts and isolated compounds: the USSING-chamber, a pharmacological model for diarrhoea, and the isolated guinea pig ileum, a model for modulatory effects on ileum contraction. Extracts and the class of polymethoxylated flavonoids showed strong inhibitory effects in both models, which provides ex-vivo evidence for the use of this botanical drug in the treatment of several gastrointestinal problems, most notably diarrhoea. The crude extract, polymethoxylated flavonoid-rich fractions and the polymethoxylated flavonoids tested showed prominent antisecretory activity. Polymethoxylated flavonoid-rich fractions also inhibited the histamine-induced contractions in the guinea pig model. The effects are not due to a single compound, but to a large number of structurally related compounds that all contribute to the effect. [source] Postnatal downregulation of inhibitory neuromuscular transmission to the longitudinal muscle of the guinea pig ileumNEUROGASTROENTEROLOGY & MOTILITY, Issue 9 2009X. Bian Abstract, Neuromuscular transmission is crucial for normal gut motility but little is known about its postnatal maturation. This study investigated excitatory/inhibitory neuromuscular transmission in vitro using ileal nerve-muscle preparations made from neonatal (,48 h postnatal) and adult (,4 months postnatal) guinea pigs. In tissues from neonates and adults, nicotine (0.3,30 ,mol L,1) contracted longitudinal muscle preparations in a tetrodotoxin (TTX) (0.3 ,mol L,1)-sensitive manner. The muscarinic receptor antagonist, scopolamine (1 ,mol L,1), reduced substantially nicotine-induced contractions in neonatal tissues but not adult tissues. In the presence of N, -nitro- l -arginine (NLA, 100 ,mol L,1) to block nitric oxide (NO) mediated inhibitory neuromuscular transmission, scopolamine-resistant nicotine-induced contractions were revealed in neonatal tissues. NLA enhanced the nicotine-induced contractions in neonatal but not in adult tissues. Electrical field stimulation (20 V; 0.3 ms; 5,25 Hz, scopolamine 1 ,mol L,1 present) caused NLA and TTX-sensitive longitudinal muscle relaxations. Frequency,response curves in neonatal tissues were left-shifted compared with those obtained in adult tissues. Immunohistochemical studies revealed that NO synthase (NOS)-immunoreactivity (ir) was present in nerve fibres supplying the longitudinal muscle in neonatal and adult tissues. However, quantitative studies demonstrated that fluorescence intensity of NOS-ir nerve fibres was higher in neonatal than adult tissues. Nerve fibres containing substance P were abundant in longitudinal muscle in adult but not in neonatal tissues. Inhibitory neuromuscular transmission is relatively more effective in the neonatal guinea pig small intestine. Delayed maturation of excitatory motor pathways might contribute to paediatric motility disturbances. [source] Presynaptic modulation of cholinergic and non-cholinergic fast synaptic transmission in the myenteric plexus of guinea pig ileumNEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2004K. J. LePard Abstract, These studies investigated receptors modulating release of mediators of fast excitatory postsynaptic potentials (fEPSPs) in guinea pig ileum myenteric plexus using electrophysiological methods. Fast EPSPs inhibited by >95% by hexamethonium (100 ,mol L,1) were cholinergic; mixed fEPSPs were inhibited <95% by hexamethonium. Non-cholinergic fEPSPs were studied in the presence of hexamethonium. The ,2-adrenergic receptor agonist UK 14304 inhibited cholinergic (maximum inhibition = 76%, EC50 = 18 nmol L,1), mixed (81%, 21 nmol L,1) and non-cholinergic (76%, 44 nmol L,1) fEPSPs equally. The 5-HT1 receptor agonist 5-carboxamidotryptamine inhibited cholinergic, mixed and non-cholinergic fEPSPs equally. Renzapride, increased non-cholinergic (33%) less than mixed (97%, 13 ,mol L,1) fEPSPs. Renzapride inhibited the purely cholinergic fEPSPs (,29%) but potentiated the cholinergic component of mixed fEPSPs (39%). Prucalopride potentiated all fEPSPs equally (30,33%). 5-HT (0.1 ,mol L,1) induced potentiation of cholinergic (75%), mixed (97%) and non-cholinergic (84%) fEPSPs was not statistically different. The potentiating effects of renzapride and 5-HT on fEPSPs were inhibited by the 5-HT4 receptor antagonist, SB 204070 (10 nmol L,1). Renzapride (0.3 ,mol L,1) blocked 5-HT-induced increases in cholinergic fEPSPs. ,2-Adrenergic and 5-HT1 receptors mediate inhibition of transmitter release from cholinergic and mixed terminals. 5-HT and prucalopride, acting at 5-HT4 receptors, facilitate all fEPSPs; renzapride facilitates the cholinergic and non-cholinergic components of mixed fEPSPs but not purely cholinergic fEPSPs. Cholinergic synapses may express few 5-HT4 receptors or a renzapride-insensitive 5-HT4 receptor isoform. [source] Oligophrenin-1, a Rho GTPase-activating protein (RhoGAP) involved in X-linked mental retardation, is expressed in the enteric nervous systemTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 2 2003Junhua Xiao Abstract Oligophrenin-1 is a RhoGTPase-activating protein (RhoGAP) that is involved in the regulation of shape changes in dendritic spines, and outgrowth of axons and dendrites in the brain. These changes in neuronal morphology are central to the mechanisms of plasticity, learning, and memory. Although the enteric nervous system also exhibits long-term changes in neuronal function, the expression and involvement of oligophrenin-1 has not previously been investigated. We show by RT-PCR analysis that oligophrenin-1 mRNA is expressed in the myenteric plexus (MP) of the guinea pig ileum. Sequencing of RT-PCR products showed that guinea pig oligophrenin-1 mRNA is 98% and 87% homologous to human and mouse oligophrenin-1, respectively, except that a 42 bp sequence is absent from the guinea pig mRNA. This 42 bp sequence codes for a sequence of 14 amino acids located near the carboxy-terminal end of the RhoGAP domain in the human sequence. An antibody that recognizes human oligophrenin-1 identified a 91 kDa protein band in rat and mouse brain lysates and in guinea pig sciatic nerve, and a 36 kDa protein band in both purified enteric ganglion cell and brain lysate from guinea pig. Oligophrenin-1 is localized specifically to neurons and varicose axons in the MPs and submucosal plexuses (SMPs) of the guinea pig and rat, but is not detectable in glial cells, smooth muscle, or other cell types. These findings indicate that oligophrenin-1 is expressed in the enteric nervous system, where it may regulate morphological changes in axons and dendrites, and thus modulate neuronal connectivity. Anat Rec Part A 273A:671,676, 2003. © 2003 Wiley-Liss, Inc. [source] Correlated morphological and chemical phenotyping in myenteric type V neurons of porcine ileumTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2002Axel Brehmer Abstract The study was aimed at the immunohistochemical characterization of myenteric Stach type V neurons of the pig ileum that were not included in the widely used Dogiel classification. So far, this conspicuous population has been defined morphologically on the basis of silver-impregnated specimens only. By using neurofilament immunohistochemistry, type V neurons that occur singly or in aggregates could be identified unequivocally and could be distinguished from other smoothly contoured myenteric neurons, i.e., type II and type IV. Double-labeling immunohistochemistry revealed a number of potentially neuroactive substances or their synthesizing enzymes to be present in type V neurons. Choline acetyltransferase immunoreactivity (-ir) was found in all type V neurons, whereas neuronal nitric oxide synthase was detected in none. Leu-enkephalin-ir was found within 92.3%, somatostatin (SOM)-ir within 91.1%, calcitonin gene-related peptide (CGRP)-ir within 80.6% and met-enkephalin-ir within 74.7% of type V neurons. Triple-labeling immunohistochemistry was applied to address the question of a specific chemical coding for myenteric type V neurons. In contrast to other combinations of neuroactive substances/enzymes that were found in both type V and other, nontype V neurons, SOM/CGRP-ir was the only combination observed exclusively within type V neurons. Both substances were colocalized in 79.3% of type V neurons. This colocalization discriminates four-fifths of the type V neurons chemically from both type II neurons (CGRP positive, SOM negative) and type IV neurons (CGRP negative, SOM positive), which both share, at first glance, a similar morphology with type V neurons. These results further support the concept of a close correlation between morphologically defined neuronal type and chemical coding and, it is likely, also function in the enteric nervous system of larger mammals. J. Comp. Neurol. 453:1,9, 2002. © 2002 Wiley-Liss, Inc. [source] Excitatory synaptic inputs on myenteric Dogiel type II neurones of the pig ileumTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 2 2001Wim Cornelissen Abstract The synaptic input on myenteric Dogiel type II neurones (n = 63) obtained from the ileum of 17 pigs was studied by intracellular recording. In 77% of the neurones, electrical stimulation of a fibre tract evoked fast excitatory postsynaptic potentials (fEPSPs) with an amplitude of 6 ± 5 mV (mean ± S.D.) and lasting 49 ± 29 ms. The nicotinic nature of the fEPSPs was demonstrated by superfusing hexamethonium (20 ,M). High-frequency stimulation (up to 20 Hz, 3 seconds) did not result in a rundown of the fEPSPs, and did not evoke slow excitatory or inhibitory postsynaptic potentials. The effects of neurotransmitters, possibly involved in these excitatory responses, were investigated. Pressure microejection of acetylcholine (10 mM in pipette) resulted in a fast nicotinic depolarisation in 67%(18/27) of the neurones (13 ± 9 mV, duration 7.0 ± 7.2 seconds) as did 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP) application (10 mM; 14 ± 10 mV, duration 4.1 ± 2.8 seconds) in 76%of the cells. The fast nicotinic response to acetylcholine was sometimes (6/27) followed by a slow muscarinic depolarisation (8 ± 4 mV; duration 38.7 ± 10.8 seconds). Immunostaining revealed 5-hydroxytryptamine hydrochloride (5-HT)- and calcitonin gene-related peptide (CGRP)-positive neuronal baskets distributed around and in close vicinity to Dogiel type II neuronal cell bodies. Microejection of 5-HT (10 mM) resulted in a fast nicotinic-like depolarisation (12 ± 6 mV, duration 3.0 ± 1.3 seconds) in 4 of 8 neurones tested, whereas microejection of CGRP (20 mM) gave rise to a slow muscarinic-like depolarisation (6 ± 2 mV, duration 56.0 ± 27.5 seconds) in 8 of 12 neurones tested. In conclusion, myenteric Dogiel type II neurones in the porcine ileum receive diverse synaptic input. Mainly with regard to the prominent presence of nicotinic responses, these neurones behave contrary to their guinea pig counterparts. J. Comp. Neurol. 432:137,154, 2001. © 2001 Wiley-Liss, Inc. [source] Real-time measurement of serotonin release and motility in guinea pig ileumTHE JOURNAL OF PHYSIOLOGY, Issue 2 2006Paul P. Bertrand Enterochromaffin (EC) cells are sensors that detect chemical or mechanical stimuli and respond with release of serotonin (5-HT). 5-HT activates local motor reflexes, but whether local motor reflexes also evoke 5-HT release is unknown. The aim of the present study was to establish the relationship between the release of 5-HT and the enteric neural circuits controlling the movements of the intestine. Recordings were made from full-thickness preparations of guinea pig ileum using electrochemical techniques with carbon fibre electrodes to measure local concentrations of 5-HT. The tension in the circular muscle (CM) and longitudinal muscle (LM) was recorded with force transducers. The release of 5-HT from the EC cells was detected selectively and the timing of the events quantified. Pressure-evoked peristalsis caused detectable 5-HT release only when the recording site was invaded by a ring of CM contraction. Spontaneous and stretch-evoked reflex contraction of the CM and LM occurred simultaneously with 5-HT release. Paralysis of the smooth muscle significantly reduced the stretch-evoked release. Muscarinic agonists evoked reflexes that were associated with increases in tension in CM and LM simultaneous with 5-HT release. Tetrodotoxin abolished the coordination between the CM contraction and 5-HT release but not the direct activation of the CM and EC cells by the agonists. In conclusion, the correlation between local motor reflexes and 5-HT release observed in the present study is caused primarily by the contraction of the smooth muscle and subsequent deformation of the mucosa. The EC cell is, thus, a site of convergence for mechanical forces that contribute to the release of 5-HT during motor reflexes. [source] Molecular Structure and QSAR Study on Antispasmodic Activity of some Xanthoxyline DerivativesARCHIV DER PHARMAZIE, Issue 5 2006Rodrigo dos Santos Abstract Semi-empirical molecular orbital calculations at AM1 level were done with the aim to investigate the structure-activity relationships of antispasmodic activities of ten 2-(X-benzyloxy)-4,6-dimethoxyacetophenones with X = H, 4,-F, 4,-NO2, 4,-CH3, 4,-Cl, 3,,4,-(CH3)2, 4,-OCH3, 4,-Br, 4,-OCH2C6H5, and 4,-C(CH3)3, against acetylcholine-induced contraction of the guinea pig ileum. The most significant quantum chemical descriptors for this series of compounds were the net atomic charges, nucleophilic and electrophilic frontier electron density, HOMO and LUMO orbitals, and reactivity indices. While no significant correlations were found employing molecular parameters such as heat of formation, dipole moment, molecular polarizability, and so on, good correlations were obtained using the reactivity indices of HOMO and LUMO orbitals at specific atoms of the molecules. These results indicate that the spatial distribution of HOMO and LUMO orbitals over these specific atoms play an important role for an increase of biological activity. [source] | ||||||||||||||||