Effect of somatostatin on myoelectrical activity of small bowel.

1978 ◽  
Vol 235 (3) ◽  
pp. E249 ◽  
Author(s):  
P Thor ◽  
R Król ◽  
S J Konturek ◽  
D H Coy ◽  
A V Schally
Keyword(s):  
Small Bowel ◽  
Spike Activity ◽  
Digestive System ◽  
Hormone Release ◽  
Myoelectrical Activity ◽  
Meat Meal ◽  
Type Pattern ◽  
Dose Dependent Decrease ◽  
Dose Dependent ◽  
Higher Doses

Somatostatin, a growth hormone-release inhibiting hormone, has been found to be a powerful inhibitor of gastric and pancreatic secretion as well as of hormone release in the digestive system. This study was undertaken to determine the influence of somatostatin on the myoelectrical activity pattern of the small bowel. Three conscious dogs were prepared with electrodes spaced 25 cm apart along the entire small intestine. Intravenous infusions of somatostatin were administered in various doses (0.6--5.0 microgram/kg.h) while spike activity and slow waves were recorded under fasting conditions, after a meat meal, or during intravenous infusion of gastrin, caerulein, or insulin. Somatostatin at a dose of 0.6 microgram/kg.h almost doubled the frequency of the interdigestive myoelectric complex. Somatostatin in fed dogs caused a dose-dependent decrease of the normal fed spike activity, and at higher doses it induced a pattern like that seen in fasting animals. The slow-wave frequency in both fasted and fed conditions was not changed significantly. We conclude that somatostatin given under basal conditions increases the frequency of the interdigestive complex and, when administered after feeding, converts the fed-type pattern to the fasted-type pattern. It may therefore play a promoting role in initiating the interdigestive myoelectric complex.

Role of prostaglandins in control of intestinal motility

1985 ◽  
Vol 248 (3) ◽  
pp. G353-G359 ◽  
Author(s):  
P. Thor ◽  
J. W. Konturek ◽  
S. J. Konturek ◽  
J. H. Anderson
Keyword(s):  
Spike Activity ◽  
Intestinal Motility ◽  
Myoelectric Activity ◽  
Physiological Control ◽  
Dependent Inhibition ◽  
Constant Dose ◽  
Dose Dependent Inhibition ◽  
Monopolar Electrodes ◽  
Dose Dependent Decrease ◽  
Dose Dependent

Intestinal myoelectric activity was measured in four conscious dogs with implanted monopolar electrodes after administration of prostaglandins (PG) and indomethacin (Indo), a potent inhibitor of PG biosynthesis. PGE2 and PGI2 given intravenously caused a dose-dependent decrease in the frequency of the migrating myoelectric complex (MMC) in fasted dogs and in postprandial spike activity in fed animals. In contrast, PGF2 alpha interrupted the MMC and caused a fedlike pattern in fasted dogs and did not affect the postprandial spike activity. Similar effects were observed after intra-arterial infusion of PGs. PGE2 and PGI2 infused into the superior mesenteric artery caused a dose-dependent inhibition of the fasted and postprandial pattern of myoelectric activity of the small bowel, whereas PGF2 alpha blocked the MMC and increased spike activity. Indo injected in a single intravenous dose caused a significant reduction in the MMC interval, and Indo infused intravenously in a constant dose induced fedlike motility pattern in fasted dogs but had little effect on the postprandial activity in these animals. This study demonstrates that exogenous PGs of E and I series administered intravenously or intra-arterially inhibit intestinal motility, whereas PGF2 alpha has opposite effects. The finding that Indo increases intestinal motility indicates that endogenous PGs are important in the physiological control of intestinal motility.

Effect of bethanechol, gastrin I, or cholecystokinin on myoelectrical activity.

1979 ◽  
Vol 236 (4) ◽  
pp. E458
Author(s):  
W J Snape ◽  
S Cohen
Keyword(s):  
Smooth Muscle ◽  
Slow Wave ◽  
Spike Activity ◽  
Control Period ◽  
Threshold Concentration ◽  
Slow Waves ◽  
Wave Frequency ◽  
Myoelectrical Activity ◽  
Dose Dependent Increase ◽  
Dose Dependent

The purpose of this study was to determine the effect of bethanechol, gastrin I, or the octapeptide of cholecystokinin (CCK-OP) on the smooth muscle of the isolated cat colon. Myoelectrical activity was recorded with monopolar glass-pore electrodes. Slow-wave frequency was 5.9 +/- 0.2 cycles/min during the basal period. Slow waves were generally coupled during the control period and the apparent propagation velocity was predominantly aborad at a velocity of 3.8 +/- 0.4 mm/s. Spike activity was superimposed on 11.9 +/- 1.5% of the slow waves during the control period. Bethanechol stimulated a dose-dependent increase in colonic spike activity, with a threshold concentration of 10(-7) M. Bethanechol did not alter the congruence of the colonic slow-wave frequency at any concentration. Gastrin I or CCK-OP increased colonic spike activity. The threshold concentrations for gastrin I and CCK-OP were 2 X 10(-11) M and 4 x 10(-11) M, respectively. Unlike bethanechol, gastrin I (2 X 10(-9) M - 2 X 10(-8) M) and CCK-OP (4 X 10(-9) - 4 X 10(-8) M) altered slow-wave frequency and decreased slow-wave congruence. These studies suggest that 1) bethanechol, gastrin I, or CCK-OP increases colonic spike activity, and 2) only gastrin I or CCK-OP alters the slow-wave frequency of colonic muscle. Thus neurohumoral substances may act independently on colonic spike activity and colonic slow-wave frequency.

lmmunotoxicological Investigation of SCMF, a New Pyrethroid Pesticide in Mice

1994 ◽  
Vol 13 (5) ◽  
pp. 337-343 ◽  
Author(s):  
Olga Siroki ◽  
L. Institoris ◽  
E. Tatar ◽  
I. Desi
Keyword(s):  
Oral Treatment ◽  
Dose Range ◽  
High Dose ◽  
Experimental Conditions ◽  
Cell Content ◽  
Pyrethroid Pesticide ◽  
Dose Dependent Decrease ◽  
Dose Dependent ◽  
Higher Doses ◽  
Femoral Bone Marrow

The toxicity of a new pyrethroid pesticide Supercypermethrin Forte (SCMF) was studied in male CFLP mice using classic toxicological (body weight, organ weights) and haematological (white blood cell count, haematocrit, nucleated cell content of femoral bone marrow) methods and immune function tests (PFC assay, DTH reaction). Four weeks of oral treatment in a 5 days per week system at doses of 1/10, 1/20, or 1/40 x LD50 did not cause evaluable changes in the measured parameters. When single calculated LD20, LD10, or LD5 doses of SCMF were administered on different days before termination to different groups of mice the two higher doses caused a time- and dose-dependent decrease in the splenic PCF number, Apart from some temporary toxic signs and an increase of haematocrit at the top dose the other examined parameters did not show evaluable changes. Under these experimental conditions toxic changes appeared only at the high dose range and, of those applied, the PFC assay proved to be the most sensitive method for detecting the toxicity of SCMF.

Influence of methionine-enkephalin and morphine on myoelectric activity of small bowel

1980 ◽  
Vol 238 (4) ◽  
pp. G384-G389 ◽  
Author(s):  
S. J. Konturek ◽  
P. Thor ◽  
R. Krol ◽  
A. Dembinski ◽  
A. V. Schally
Keyword(s):  
Small Bowel ◽  
Spike Activity ◽  
Intravenous Infusion ◽  
Alimentary Tract ◽  
Opioid Antagonist ◽  
Myoelectric Activity ◽  
Methionine Enkephalin ◽  
Naturally Occurring ◽  
Entire Small Intestine ◽  
Meat Meal

Enkephalins, naturally occurring peptides with powerful opiatelike effects, have recently been detected throughout the tissues of the alimentary tract, but their role is unknown. This study was designed to compare the effects of methionine-enkephalin (met-enkephalin) and morphine on the myoelectrical pattern of the small bowel. Five conscious dogs were prepared with electrodes spaced 25 cm apart along the entire small intestine. Spike activity and slow waves were recorded with a Beckman Dynograph. Records were obtained in fasted conditions and following a meat meal or intravenous infusion of caerulein while animals received intravenous infusion of either met-enkephalin or morphine in various doses (range 10-160 microgram/kg . h). Met-enkephalin at a dose of 40 microgram/kg . h caused a significant decrease in spike activity and in the frequency of bursts of the interdigestive myoelectric complexes (IMC), whereas morphine almost doubled the frequency of the IMC. Met-enkephalin in dogs given food or infused with caerulein significantly decreased the fed-type spike activity of the small bowel, whereas morphine did not affect it. The effects of met-enkephalin and morphine on the intestinal myoelectrical pattern can be reversed by naloxone, an opioid antagonist, suggesting that they are mediated by separate opioid receptors.

scholarly journals Effect of Caffeine at Different Concentrations on Behavior and Motor Activity in Mice

2020 ◽  
pp. 1-11
Author(s):  
Sakina S. Saadawi ◽  
Khairi A. Alennabi ◽  
Sumaya Baayo ◽  
Amera Fares ◽  
Najwa Alosta ◽  
...  
Keyword(s):  
Motor Activity ◽  
Spontaneous Motor Activity ◽  
Antidepressant Effect ◽  
Plus Maze ◽  
Dose Dependent Decrease ◽  
Post Hoc ◽  
Dose Dependent ◽  
Cns Depression ◽  
Higher Doses ◽  
Dose Dependent Effect

Aims: This article aimed to study the effect of different caffeine concentrations on behaviour and motor activity of mice. Place and Duration of Study: This study took place in Faculty of Pharmacy, University of Tripoli, and was conducted between 2017 to 2018. Methodology: The experiment was carried out using 24 male mice (25-30 gm). Plus maze was used for screening antianxiety effect of caffeine. While swimming maze was used to test the antidepressant effect. Descriptive statistics was performed using SPSS (version 22), followed by one sample Kolmogorov-Simirnov test. One-Way ANOVA was applied to compare between groups and Post Hoc test (LSD).  Results: At a dose of 100 mg/kg, caffeine produce significant decrease in the duration of immobility using forced swimming maze; while the lower (25 mg/kg) and the higher (200 mg/kg) doses did not produce any changes compared to the control. In plus maze, Caffeine decreases the anxiety measure at the dose used of 100 mg/kg; but did not change the anxiety measure when lower (25 mg/kg) or higher (200 mg/kg) doses used compared to the control. The spontaneous motor activity was decreased significantly after administration of the higher dose of 200 mg/kg; the lower dose (25 mg/kg) showed insignificant increase, while the dose of 100 mg/kg produce insignificant decrease in the spontaneous motor activity. Conclusion: Caffeine has dose dependent effect, in a dose 100 mg/kg it produce anxiolytic and antidepressant like action, while lower (25 mg/kg) and higher (200 mg/kg) doses did not show any changes. Caffeine also produce dose dependent decrease in the spontaneous motor activity, this indicate that caffeine produce CNS depression with higher doses.

Involvement of 5-Hydroxytryptamine in Platelet Aggregation In Vivo in Rats and Guinea Pigs

1989 ◽  
Vol 61 (03) ◽  
pp. 463-467 ◽  
Author(s):  
G M Smith
Keyword(s):  
Platelet Count ◽  
Guinea Pigs ◽  
Platelet Adhesion ◽  
Adenosine Diphosphate ◽  
Rate Of Return ◽  
Low Doses ◽  
Dose Dependent ◽  
Higher Doses ◽  
Rat Platelets

SummaryIn this study, 5-hydroxytryptamine (5-HT) caused a dose- dependent fall in the circulating platelet count suggesting that 5-HT receptors are activated in rat platelets to cause platelet adhesion and aggregation. When low doses of adenosine diphosphate (ADP) were simultaneously injected with 5-HT, there was a significant potentiation of the responses to ADR Ketanserin significantly reduced the potentiated responses. When higher doses of ADP were infused with bolus injections of 5-HT there was no potentiation and ketanserin did not reduce these responses. Ketanserin did not inhibit the collagen-induced fall in circulating platelet count, but did significantly increase the rate of return to the basal platelet count compared with control. 5-HT did not cause a fall in platelet count in guinea-pigs

Outcome of Treatment of Deep-Vein Thrombosis with Urokinase: Relationship to Dosage, Duration of Therapy, Age of the Thrombus and Laboratory Changes

1984 ◽  
Vol 51 (02) ◽  
pp. 236-239 ◽  
Author(s):  
A D’Angelo ◽  
P M Mannucci
Keyword(s):  
Degradation Products ◽  
High Rate ◽  
Bleeding Complications ◽  
Vein Thrombosis ◽  
Treatment Regimens ◽  
Duration Of Therapy ◽  
Laboratory Changes ◽  
Deep Vein ◽  
Dose Dependent ◽  
Higher Doses

SummaryForty-one patients with phlebographically proven DVT of the popliteal, femoral or iliac veins were treated with different regimens of urokinase (UK) given by continuous intravenous infusion. The four groups were comparable with respect to localization, extension and estimated age of the thrombi. Another phlebographic picture was taken within 48 hr after the end of UK infusion. Substantial lysis had occurred in 2 of 10 patients treated with 1500 U/kg/h for 2 days, in 4 of 11 treated with 2500/U/kg/h for 3 days, in 2 of 10 treated with 2500 U/kg/h for 7 days and in 4 of 10 treated with 4000 U/kg/h for 4 days. Only thrombi younger than 8 days could be lysed, with 61% (8/13) rate of lysis for thrombi less than 5 days old. Bleeding complications were observed more frequently with the higher doses and longer durations of therapy. The four treatment regimens all induced dose-dependent changes in fibrinogen, fibrin(ogen) degradation products, plasminogen and antiplasmin. Neither pre- nor postinfusion values of these parameters could differentiate patients with lysis from those without lysis. It is concluded that UK can provoke a high rate of thrombolysis of DVT treated early after the appearance of symptoms but that there is no relationship between UK-induced modifications of fibrinolysis and the outcome of therapy.

Insulin secretion and substrate homeostasis in prolonged hypothermia in rats

1988 ◽  
Vol 255 (6) ◽  
pp. R1035-R1040
Author(s):  
R. Hoo-Paris ◽  
M. L. Jourdan ◽  
L. C. Wang ◽  
R. Rajotte
Keyword(s):  
Insulin Secretion ◽  
Plasma Glucose ◽  
Low Temperatures ◽  
Plasma Insulin ◽  
Glucose Utilization ◽  
Exogenous Insulin ◽  
Metabolic Substrate ◽  
Endogenous Insulin ◽  
Dose Dependent Decrease ◽  
Dose Dependent

In hypothermia, impairment of metabolic substrate mobilization and utilization may be a factor limiting survival. By use of a newly developed technique, substrate profiles and their regulation by insulin were examined in hypothermic rats (body temperature 19 degrees C) over 24 h. Plasma glucose concentrations increased to approximately 300 mg/dl during cooling and remained high throughout the period of hypothermia. Free fatty acid (FFA) concentration was not altered during cooling or during the first 10 h of hypothermia (approximately 700 mu eq/l) but progressively decreased thereafter, reaching 420 mu eq/l by 20 h. Plasma insulin decreased dramatically during cooling and remained very low (9 +/- 2 microU/ml) during the whole period of hypothermia, reflecting the suppression of insulin secretion by isolated islets at low temperatures. To test he hypothesis that suppression of endogenous insulin secretion may hamper glucose utilization and thus limit survival in hypothermia, exogenous insulin was administered. At doses of 0.1, 0.5, and 1 U/kg intravenously, insulin slowly decreased plasma glucose and FFA. However, at 0.1 and 1 U/kg intraperitoneally, insulin resulted in a dose-dependent decrease in survival time in the hypothermic rat. It is possible that the antilipolytic effect of insulin may have outweighed any beneficial effect of improving glucose utilization in hypothermia.

scholarly journals A Reversible Shift of Driver Dependence from EGFR to Notch1 in Non-Small Cell Lung Cancer as a Cause of Resistance to Tyrosine Kinase Inhibitors

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2022
Author(s):  
Francesca Iommelli ◽  
Viviana De Rosa ◽  
Cristina Terlizzi ◽  
Rosa Fonti ◽  
Rosa Camerlingo ◽  
...  
Keyword(s):  
Kinase Inhibitors ◽  
Epithelial Mesenchymal Transition ◽  
Parental Cell ◽  
Egfr Inhibitors ◽  
Simultaneous Increase ◽  
Adherent Cells ◽  
Binding Assays ◽  
Mesenchymal Transition ◽  
Dose Dependent Decrease ◽  
Dose Dependent

Notch1 plays a key role in epithelial-mesenchymal transition (EMT) and in the maintenance of cancer stem cells. In the present study we tested whether high levels of activated Notch1 in oncogene-driven NSCLC can induce a reversible shift of driver dependence from EGFR to Notch1, and thus causing resistance to EGFR inhibitors. Adherent cells (parental) and tumor spheres (TS) from NSCLC H1975 cells and patient-derived CD133-positive cells were tested for EGFR and Notch1 signaling cascade. The Notch1-dependent modulation of EGFR, NCID, Hes1, p53, and Sp1 were then analyzed in parental cells by binding assays with a Notch1 agonist, DLL4. TS were more resistant than parental cells to EGFR inhibitors. A strong upregulation of Notch1 and a concomitant downregulation of EGFR were observed in TS compared to parental cells. Parental cell exposure to DLL4 showed a dose-dependent decrease of EGFR and a simultaneous increase of NCID, Hes1, p53, and Sp1, along with the dislocation of Sp1 from the EGFR promoter. Furthermore, an enhanced interaction between p53 and Sp1 was observed in TS. In NSCLC cells, high levels of active Notch1 can promote a reversible shift of driver dependence from EGFR to Notch1, leading to resistance to EGFR inhibitors.

scholarly journals Biological Effect of Different Spinach Extracts in Comparison with the Individual Components of the Phytocomplex

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 382
Author(s):  
Laura Arru ◽  
Francesca Mussi ◽  
Luca Forti ◽  
Annamaria Buschini
Keyword(s):  
Antioxidant Defense ◽  
Extraction Methods ◽  
Oxidizing Agent ◽  
Endogenous Reactive Oxygen Species ◽  
Dependent Activity ◽  
Main Components ◽  
The Individual ◽  
Dose Dependent ◽  
Higher Doses ◽  
Oxidative Insult

The Mediterranean-style diet is rich in fruit and vegetables and has a great impact on the prevention of major chronic diseases, such as cardiovascular diseases and cancer. In this work we investigated the ability of spinach extracts obtained by different extraction methods and of the single main components of the phytocomplex, alone or mixed, to modulate proliferation, antioxidant defense, and genotoxicity of HT29 human colorectal cells. Spinach extracts show dose-dependent activity, increasing the level of intracellular endogenous reactive oxygen species (ROS) when tested at higher doses. In the presence of oxidative stress, the activity is related to the oxidizing agent involved (H2O2 or menadione) and by the extraction method. The single components of the phytocomplex, alone or mixed, do not alter the intracellular endogenous level of ROS but again, in the presence of an oxidative insult, the modulation of antioxidant defense depends on the oxidizing agent used. The application of the phytocomplex extracts seem to be more effective than the application of the single phytocomplex components.

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