Changes in spontaneous contractions of rat ileum by aflatoxin in vitro

2008 ◽  
Vol 46 (6) ◽  
pp. 2124-2127 ◽  
Author(s):  
Nevcihan Gursoy ◽  
Bulent Sarac ◽  
Nedim Durmus ◽  
Ahmet Parlak ◽  
Sahin Yildirim ◽  
...  
Keyword(s):  
Rat Ileum ◽  
Spontaneous Contractions

scholarly journals Antispasmodic Effect of Blackcurrant (Ribes nigrum L.) Juice and Its Potential Use as Functional Food in Gastrointestinal Disorders

2018 ◽  
Vol 27 (2) ◽  
pp. 179-185 ◽  
Author(s):  
Bojana Miladinovic ◽  
Suzana  Brankovic ◽  
Milica Kostic ◽  
Milica Milutinovic ◽  
Nemanja Kitic ◽  
...  
Keyword(s):  
Functional Food ◽  
Statistical Significance ◽  
Barium Chloride ◽  
Gastrointestinal Disorders ◽  
Spasmolytic Activity ◽  
Rat Ileum ◽  
Antispasmodic Effect ◽  
Spontaneous Contractions ◽  
Isolated Rat

Objective: The purpose of this study was to investigate the relaxative effects of blackcurrant juice on the gastrointestinal smooth muscle in vitro. Materials and Methods: Berries of the blackcurrant cultivar Ometa were used for the preparation of the juice used. The spasmolytic activity of blackcurrant juice was tested on rat ileum isolated from male Wistar rats by monitoring its influence on spontaneous contractions, as well as contractions induced by potassium chloride (KCl), barium chloride (BaCl2), calcium chloride (CaCl2), and acetylcholine (Ach). The results are expressed as the mean ± standard deviation obtained in 6 measurements and statistical significance was determined by the Student t test, with p < 0.05 taken as significant. Results: The blackcurrant cultivar Ometa significantly reduced the frequency and the amplitude of spontaneous contractions (57.94 ± 3.44%) and Ach-induced contractions (42.74 ± 5.36%; p < 0.05) of the isolated rat ileum. Cumulative concentrations (0.01–3 mg/mL) of the Ometa juice also reduced contractions of the isolated rat ileum stimulated by KCl (51.46 ± 6.87%), CaCl2 (57.54 ± 6.47%), and BaCl2 (58.54 ± 10.55%). The inhibitory effects of the juice were proportional to the applied concentration. Conclusion: The antispasmodic effect of Ometa cultivar shows that common gastrointestinal disorders could be treated by the functional food.

scholarly journals SPONTANEOUS CONTRACTIONS OF THE HUMAN OVARY IN VITRO

Reproduction ◽  
1972 ◽  
Vol 28 (1) ◽  
pp. 113-115 ◽  
Author(s):  
Z. PALTI ◽  
M. FREUND
Keyword(s):  
Human Ovary ◽  
Spontaneous Contractions

scholarly journals Contractile activity is required for the expression of neonatal myosin heavy chain in embryonic chick pectoral muscle cultures.

1986 ◽  
Vol 103 (6) ◽  
pp. 2153-2161 ◽  
Author(s):  
L C Cerny ◽  
E Bandman
Keyword(s):  
Monoclonal Antibody ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Contractile Activity ◽  
Pectoral Muscle ◽  
Chicken Muscle ◽  
High K ◽  
Muscle Cultures ◽  
Spontaneous Contractions

The expression of neonatal myosin heavy chain (MHC) was examined in developing embryonic chicken muscle cultures using a monoclonal antibody (2E9) that has been shown to be specific for that isoform (Bandman, E., 1985, Science (Wash. DC), 227: 780-782). After 1 wk in vitro some myotubes could be stained with the antibody, and the number of cells that reacted with 2E9 increased with time in culture. All myotubes always stained with a second monoclonal antibody that reacted with all MHC isoforms (AG19) or with a third monoclonal antibody that reacted with the embryonic but not the neonatal MHC (EB165). Quantitation by ELISA of an extract from 2-wk cultures demonstrated that the neonatal MHC represented between 10 and 15% of the total myosin. The appearance of the neonatal isoform was inhibited by switching young cultures to medium with a higher [K+] which has been shown to block spontaneous contractions of myotubes in culture. Furthermore, if mature cultures that reacted with the neonatal antibody were placed into high [K+] medium, neonatal MHC disappeared from virtually all myotubes within 3 d. The effect of high [K+] medium was reversible. When cultures maintained in high [K+] medium for 2 wk were placed in standard medium, which permitted the resumption of contractile activity, within 24 h cells began to react with the neonatal specific antibody, and by 72 h many myotubes were strongly positive. Since similar results were also obtained by inhibiting spontaneous contractions with tetrodotoxin, we suggest that the development of contractile activity is not only associated with the maturation of myotubes in culture, but may also be the signal that induces the expression of the neonatal MHC.

Seminal vesicle response to androgen with adrenaline, noradrenaline and acetylcholine

1960 ◽  
Vol 198 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Jerome A. Grunt ◽  
James T. Higgins
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Seminal Vesicle ◽  
Testosterone Propionate ◽  
Water Soluble ◽  
Muscle System ◽  
Motor End Plate ◽  
Organ Response ◽  
Spontaneous Contractions

In a study of the end-organ response to androgen, use has been made of the seminal vesicle of the rat. Observations were made of the in vitro spontaneous contractions and responses to autonomic stimulating drugs. Vesicles of castrated rats contract spontaneously in vitro. Testosterone propionate given to the rat before sacrifice inhibits contractions, as does injection of water-soluble androgen into the in vitro chamber. Vesicles of castrates have lower thresholds to adrenaline and possibly to acetylcholine, but not to noradrenaline. The thresholds to acetylcholine but not to noradrenaline are elevated after injection of water-soluble androgen into the in vitro chamber. Several interpretations are discussed. Androgen and the autonomic nervous system probably interact at or near the cell membrane of the vesicle musculature. The three drugs tested most likely act at different loci along the nerve—motor end plate—muscle system, and noradrenaline is probably not a primary mediating agent of spontaneous contractions of the vesicle of the castrated rat.

Neural regulation of in vitro giant contractions in the rat colon

2001 ◽  
Vol 281 (1) ◽  
pp. G275-G282 ◽  
Author(s):  
Asensio Gonzalez ◽  
Sushil K. Sarna
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Sch 23390 ◽  
Circular Muscle ◽  
Electrical Field Stimulation ◽  
Muscle Cells ◽  
Enteric Neurons ◽  
Rat Colon ◽  
Spontaneous Contractions

The rat middle colon spontaneously generates regularly occurring giant contractions (GCs) in vitro. We investigated the neurohumoral and intracellular regulation of these contractions in a standard muscle bath. cGMP content was measured in strips and single smooth muscle cells. The circular muscle strips generated spontaneous GCs. Their amplitude and frequency were significantly increased by tetrodotoxin (TTX), ω-conotoxin, N ω-nitro-l-arginine (l-NNA), and the dopamine D1 receptor antagonist Sch-23390. The GCs were unaffected by hexamethonium, atropine, and antagonists of serotonergic (5-HT1–4), histaminergic (H1–2), and tachykininergic (NK1–2) receptors but enhanced by NK3receptor antagonism. The guanylate cyclase inhibitor 1H-[1,2,4]oxidiazolo[4,3-a]quinoxalin-1-one (ODQ) also enhanced GCs to the same extent as TTX and l-NNA, and each of the three agents prevented the effects of the others. GCs were abolished by electrical field stimulation, S-nitroso- N-acetyl-penicillamine, and 8-bromo-cGMP. BAY-K-8644 and apamin enhanced the GCs, but they were abolished by D-600. Basal cGMP content in strips was decreased by TTX,l-NNA, or ODQ, but these treatments had no effect on cGMP content of enzymatically dissociated single smooth muscle cells. We conclude that spontaneous contractions in the rat colonic muscle strips are not generated by cholinergic, serotonergic, or histaminergic input. Constitutive release of nitric oxide from enteric neurons sustains cGMP synthesis in the colonic smooth muscle to suppress spontaneous in vitro GCs.

Sources and implications of basal nitric oxide in spontaneous contractions of guinea pig taenia caeci

2003 ◽  
Vol 285 (4) ◽  
pp. G747-G753 ◽  
Author(s):  
Catalina Caballero-Alomar ◽  
Carmen Santos ◽  
Diego Lopez ◽  
M. Teresa Mitjavila ◽  
Pere Puig-Parellada
Keyword(s):  
Nitric Oxide ◽  
Guinea Pig ◽  
Inhibitory Effect ◽  
No Production ◽  
Paramagnetic Resonance ◽  
Synthase Inhibitor ◽  
Spontaneous Contractions ◽  
Electron Paramagnetic

We examined in vitro the source and role of basal nitric oxide (NO) in proximal segments of guinea pig taenia caeci in nonadrenergic, noncholinergic (NANC) conditions. Using electron paramagnetic resonance (EPR), we measured the effect of the NO synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME, 10–4 M), the neuronal blocker tetrodotoxin (TTX, 10–6 M), or both on spontaneous contractions and on the production of basal NO. Both l-NAME and TTX, when tested alone, increased the amplitude and frequency of contractions. NO production was abolished by l-NAME and was inhibited by 38% by TTX. When tested together, l-NAME in the presence of TTX or TTX in the presence of l-NAME had no further effect on the amplitude or frequency of spontaneous contractions, and the NO production was inhibited. These findings suggest that basal NO consists of TTX-sensitive and TTX-resistant components. The TTX-sensitive NO has an inhibitory effect on spontaneous contractions; the role of TTX-resistant NO is unknown.

Functional and structural alterations of epithelial barrier properties of rat ileum following X-irradiation

2004 ◽  
Vol 82 (2) ◽  
pp. 84-93 ◽  
Author(s):  
I Dublineau ◽  
F Lebrun ◽  
S Grison ◽  
N M Griffiths
Keyword(s):  
Intestinal Permeability ◽  
Intestinal Barrier ◽  
Barrier Properties ◽  
Epithelial Tissue ◽  
Barrier Integrity ◽  
Rat Ileum ◽  
Ussing Chambers ◽  
Junctional Proteins ◽  
X Irradiation

Irradiation of the digestive system leads to alterations of the small intestine. We have characterized the disruption of the barrier integrity in rat ileum from 1 to 14 days following irradiation ranging from 6 to 12 Gy. The intestinal permeability to 14C-mannitol and 3H-dextran 70 000 was measured in vitro in Ussing chambers. In parallel to these functional studies, immunohistochemical analyses of junctional proteins (ZO-1 and β-catenin) of ileal epithelium were performed by confocal microscopy. Irradiation with 10 Gy induced a marked decrease in epithelial tissue resistance at three days and a fivefold increase in mannitol permeability, without modifications of dextran permeability. A disorganization of the localization for ZO-1 and β-catenin was also observed. At 7 days after irradiation, we observed a recovery of the organization of junctional proteins in parallel to a return of intestinal permeability to control value. In addition to these time-dependent effects, a gradual effect on epithelial integrity of the radiation doses was observed 3 days after irradiation. This study shows a disruption of the integrity of the intestinal barrier in rat ileum following abdominal X-irradiation, depending on the time postirradiation and on the delivered dose. The loss of barrier integrity was characterized by a disorganization of proteins of tight and adherent junctions, leading to increased intestinal permeability to mannitol.Key words: intestinal permeability, ZO-1, β-catenin, tight and adherent junctions.

The α2-isoform of Na-K-ATPase mediates ouabain-induced hypertension in mice and increased vascular contractility in vitro

2005 ◽  
Vol 288 (2) ◽  
pp. H477-H485 ◽  
Author(s):  
Iva Dostanic ◽  
Richard J. Paul ◽  
John N. Lorenz ◽  
Steven Theriault ◽  
James W. Van Huysse ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Left Ventricular ◽  
Genetically Engineered ◽  
Wild Type ◽  
Vascular Contractility ◽  
Genetically Engineered Mice ◽  
Basal Tone ◽  
Induced Hypertension ◽  
Spontaneous Contractions

Although ouabain is known to induce hypertension, the mechanism of how this cardiac glycoside affects blood pressure is uncertain. The present study demonstrates that the α2-isoform of the Na-K-ATPase mediates the pressor effects of ouabain in mice. To accomplish this, we analyzed the effect of ouabain on blood pressure in wild-type mice, where the α2-isoform is sensitive to ouabain, and genetically engineered mice expressing a ouabain-insensitive α2-isoform of the Na-K-ATPase. Thus differences in the response to ouabain between these two genotypes can only be attributed to the α2-isoform of Na-K-ATPase. As the α1-isoform is naturally resistant to ouabain in rodents, it will not be inhibited by ouabain in either genotype. Whereas prolonged administration of ouabain increased levels of ouabain in serum from both wild-type and targeted animals, hypertension developed only in wild-type mice. In addition, bolus intravenous infusion of ouabain increased the systolic, mean arterial, and left ventricular blood pressure in only wild-type anesthetized mice. In vitro, ouabain increased vascular tone and thereby phenylephrine-induced contraction of the aorta in intact and endothelium-denuded wild-type mice but in α2-resistant mice. Ouabain also increased the magnitude of the spontaneous contractions of portal vein and the basal tone of the intact aorta from only wild-type mice. The increase in aortic basal tone was dependent on the presence of endothelium. Our studies also demonstrate that the α2-isoform of Na-K-ATPase mediates the ouabain-induced increase in vascular contractility. This could play a role in the development and maintenance of ouabain-induced hypertension.

scholarly journals Reversal by relaxin of altered ileal spontaneous contractions in dystrophic (mdx) mice through a nitric oxide-mediated mechanism

2007 ◽  
Vol 293 (2) ◽  
pp. R662-R668 ◽  
Author(s):  
M. C. Baccari ◽  
S. Nistri ◽  
M. G. Vannucchi ◽  
F. Calamai ◽  
D. Bani
Keyword(s):  
Nitric Oxide ◽  
Mdx Mice ◽  
No Production ◽  
Mechanical Responses ◽  
Spontaneous Motility ◽  
Gastrointestinal Motor ◽  
Displacement Transducers ◽  
Spontaneous Contractions ◽  
Nos Isoforms

Altered nitric oxide (NO) production/release is involved in gastrointestinal motor disorders occurring in dystrophic (mdx) mice. Since the hormone relaxin (RLX) can upregulate NO biosynthesis, its effects on spontaneous motility and NO synthase (NOS) expression in the ileum of dystrophic (mdx) mice were investigated. Mechanical responses of ileal preparations were recorded in vitro via force-displacement transducers. Evaluation of the expression of NOS isoforms was performed by immunohistochemistry and Western blot. Normal and mdx mice were distributed into three groups: untreated, RLX pretreated, and vehicle pretreated. Ileal preparations from the untreated animals showed spontaneous muscular contractions whose amplitude was significantly higher in mdx than in normal mice. Addition of RLX, alone or together with l-arginine, to the bath medium depressed the amplitude of the contractions in the mdx mice, thus reestablishing a motility pattern typical of the normal mice. The NOS inhibitor NG-nitro-l-arginine (l-NNA) or the guanylate cyclase inhibitor ODQ reversed the effects of RLX. In RLX-pretreated mdx mice, the amplitude of spontaneous motility was reduced, thus resembling that of the normal mice, and NOS II expression in the muscle coat was increased in respect to the vehicle-pretreated mdx animals. These results indicate that RLX can reverse the altered ileal motility of mdx mice to a normal pattern, likely by upregulating NOS II expression and NO biosynthesis in the ileal smooth muscle.

Reversal of nerve damage in streptozotocin-diabetic rats by acute application of insulin in vitro

1988 ◽  
Vol 75 (6) ◽  
pp. 629-635 ◽  
Author(s):  
Geoffrey Burnstock ◽  
Rhona Mirsky ◽  
Abebech Belai
Keyword(s):  
Vasoactive Intestinal Polypeptide ◽  
Calcitonin Gene Related Peptide ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Rat Ileum ◽  
Related Peptide ◽  
Calcitonin Gene ◽  
Enteric Nerves ◽  
Intestinal Polypeptide

1. Immunohistochemical, immunoblotting and release experiments were performed on ileum from control rats, from 8-week streptozotocin-diabetic rats and from diabetic rats after acute application of insulin in vitro. 2. There was an increase in vasoactive-intestinal-polypeptide-like and a decrease in calcitonin-gene-related-peptide-like immunoreactivity in the myenteric plexus of the diabetic rat ileum, although electrically evoked release of both peptides from enteric nerves was defective. Acute application of insulin in vitro reversed the defective release and changes in immunoreactivity of vasoactive intestinal polypeptide and calcitonin-gene-related peptide seen in the enteric nerves of streptozotocin-diabetic rat ileum. 3. In addition, using a monoclonal neurofilament antibody RT 97 that recognizes a phosphorylated neurofilament epitope present in normal enteric nerves, it was shown that this phosphorylated neurofilament epitope was absent in diabetic nerves, even though a polyclonal neurofilament antibody revealed that neurofilaments were present in both axons and cell bodies of the myenteric plexus of diabetic rat ileum. After only 2 h of insulin incubation in vitro, the phosphorylated neurofilament epitope was again present in the nerves. 4. It is suggested that the abnormal distribution of phosphorylated neurofilaments and defective storage and release of vasoactive intestinal polypeptide and calcitonin-gene-related peptide in the present study may be a more general feature of diabetes. The restoration of these abnormalities by continuous acute insulin application in vitro shown here suggests that the availability of a steady level of insulin might prevent some of the changes which occur in early stages of diabetes. If so, this could influence the use of insulin in the treatment of diabetes, particularly in view of the recent report that short-term continuous subcutaneous insulin infusion restores the function of the autonomic and peripheral nerves in type I diabetic patients [Krönert, K., Hülsen, J., Luft, D., Stetter, T. & Eggstein, M. (1987) Journal of Clinical Endocrinology and Metabolism, 64, 1219–1223].

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