Interdigestive migrating contractions are coregulated by ghrelin and motilin in conscious dogs

2012 ◽  
Vol 302 (2) ◽  
pp. R233-R241 ◽  
Author(s):  
Atsushi Ogawa ◽  
Erito Mochiki ◽  
Mitsuhiro Yanai ◽  
Hiroki Morita ◽  
Yoshitaka Toyomasu ◽  
...  
Keyword(s):  
Conscious Dogs ◽  
Phase Iii ◽  
Motility Index ◽  
Growth Hormone Secretagogue ◽  
Plasma Motilin ◽  
Interdigestive Migrating Contractions ◽  
Rats And Mice ◽  
The Relationship ◽  
Gi Motility

During fasting, gastrointestinal (GI) motility is characterized by cyclical motor contractions. These contractions have been referred to as interdigestive migrating contractions (IMCs). In dogs and humans, IMCs are known to be regulated by motilin. However, in rats and mice, IMCs are regulated by ghrelin. It is not clear how these peptides influence each other in vivo. The aim of the present study was to investigate the relationship between ghrelin and motilin in conscious dogs. Twenty healthy beagles were used in this study. Force transducers were implanted in the stomach, duodenum, and jejunum to monitor GI motility. Subsequent GI motility was recorded and quantified by calculating the motility index. In examination 1, blood samples were collected in the interdigestive state, and levels of plasma ghrelin and motilin were measured. Plasma motilin peaks were observed during every gastric phase III, and plasma ghrelin peaks occurred in nearly every early phase I. Plasma motilin and ghrelin levels increased and decreased cyclically with the interdigestive states. In examination 2, saline or canine ghrelin was administered intravenously during phase II and phase III. After injection of ghrelin, plasma motilin levels were measured. Ghrelin injection during phases II and III inhibited phase III contractions and decreased plasma motilin levels. In examination 3, ghrelin was infused in the presence of the growth hormone secretagogue receptors antagonist [d-Lys3]-GHRP-6. Continuous ghrelin infusion suppressed motilin release, an effect abrogated by the infusion of [d-Lys3]-GHRP-6. Examination 4 was performed to evaluate the plasma ghrelin response to motilin administration. Motilin infusion immediately decreased ghrelin levels. In this study, we demonstrated that motilin and ghrelin cooperatively control the function of gastric IMCs in conscious dogs. Our findings suggest that ghrelin regulates the function and release of motilin and that motilin may also regulate ghrelin.

Initiation of migrating myoelectric complexes in human subjects: role of duodenal acidification and plasma motilin

1981 ◽  
Vol 59 (2) ◽  
pp. 173-179 ◽  
Author(s):  
E. E. Daniel ◽  
J. E. T. Fox ◽  
S. M. Collins ◽  
T. D. Lewis ◽  
M. Meghji ◽  
...  
Keyword(s):  
Human Subjects ◽  
Duodenal Bulb ◽  
Maximal Activity ◽  
Phase Iii ◽  
Motor Complex ◽  
Duodenal Acidification ◽  
Normal Human ◽  
Plasma Motilin ◽  
The Relationship

The hypothesis that acid, emptied intermittently from the stomach during fasting, might initiate the duodenal phase of the migrating motor complex was tested in normal human subjects, in addition, the relationship between plasma motilin concentrations and the initiation of migrating motor complexes was examined. Migrating complexes occurred spontaneously in the absence of acid in the duodenal bulb and in the presence of duodenal bulb neutralization with sodium bicarbonate. Thus duodenal bulb acidification is not necessary for initiation of the duodenal phase of the migrating motor complexes. Further-more, cyclical increases in plasma motilin concentrations were not closely correlated with the initiation of the gastric phase of maximal activity of the migrating motor complexes. However, motilin concentrations were decreased significantly following onset of the duodenal phase III. We conclude that neither duodenal acidification nor increases in motilin concentration are necessary to initiate migrating motor complexes in man.

Neural isolation of the entire canine stomach in vivo: effects on motility

1989 ◽  
Vol 257 (1) ◽  
pp. G30-G40 ◽  
Author(s):  
J. A. Van Lier Ribbink ◽  
M. G. Sarr ◽  
M. Tanaka
Keyword(s):  
Small Intestine ◽  
Motor Activity ◽  
Motor Pattern ◽  
Phase Iii ◽  
Myoelectric Activity ◽  
Motor Patterns ◽  
Gastric Motor Activity ◽  
Plasma Motilin ◽  
In Vivo Effects

This study was designed to determine the effects of transection of all extrinsic and enteric neural continuity to the entire stomach on motility patterns of the stomach and small intestine. Five dogs were subjected to a model of orthotopic autotransplantation of the stomach to achieve an in vivo, "neurally isolated" stomach. Manometric catheters and serosal electrodes were implanted. A cyclic motor pattern occurred during fasting and was closely coordinated temporally with the migrating motor complex (MMC) in the small bowel. The period of the cyclic gastric motor activity did not differ from the period of the MMC in the small intestine [121 +/- 8 vs 124 +/- 10 (means +/- SE) min, P = 0.4], but the periods of both were greater than in control dogs (93 +/- 5 min, P less than 0.05). Tachygastria accounted for 36 +/- 13% of fasting myoelectric activity in the neurally isolated dogs and for less than 1% in control dogs. Plasma concentration of motilin was greatest during the phase III-like gastric motor activity; exogenous motilin induced premature phase III-like activity in the stomach and small intestine. Feeding abolished the cyclic motor activity in the stomach and decreased plasma motilin concentration. These data suggest that hormonal factors, and not extrinsic or intrinsic neural continuity to the stomach, may control both the initiation of a cyclic interdigestive gastric motor pattern and its temporal coordination with motor patterns in the small intestine.

Motilin controls cyclic release of insulin through vagal cholinergic muscarinic pathways in fasted dogs

1998 ◽  
Vol 274 (1) ◽  
pp. G87-G95 ◽  
Author(s):  
Hideki Suzuki ◽  
Erito Mochiki ◽  
Norihiro Haga ◽  
Minoru Satoh ◽  
Akiyoshi Mizumoto ◽  
...  
Keyword(s):  
Insulin Release ◽  
Islet Cells ◽  
Contractile Activity ◽  
Close Association ◽  
Phase Iii ◽  
Force Transducers ◽  
Specific Radioimmunoassay ◽  
Plasma Motilin ◽  
Interdigestive Migrating Contractions ◽  
Perifusion System

The effect of motilin on insulin release has not been studied in the interdigestive state. Adult mongrel dogs were chronically implanted with force transducers in the stomach and duodenum to monitor contractile activity, and the plasma motilin and insulin concentrations were measured by a specific radioimmunoassay and enzyme immunoassay, respectively. The concentration of insulin in plasma was found to fluctuate in close association with that of motilin and phase III of the interdigestive migrating contractions in the stomach. This spontaneous release of insulin was mimicked by intravenous infusion of motilin at a dose of 0.3 μg ⋅ kg−1⋅ h−1. Exogenous motilin (0.01–0.3 μg/kg) dose dependently stimulated insulin release, which was abolished by atropine, hexamethonium, ondansetron, and truncal vagotomy. Phentolamine significantly enhanced, whereas propranolol inhibited, motilin-induced insulin release. In a perifusion system using islet cells from the canine pancreas, motilin did not affect insulin release. In conclusion, motilin stimulates insulin release through vagal cholinergic, muscarinic receptors on pancreatic β-cells, and the effect appears to be modulated by adrenergic nerves.

Measurement of resistance to flow across antroduodenal area during fasting

1986 ◽  
Vol 250 (6) ◽  
pp. G773-G780 ◽  
Author(s):  
F. Mearin ◽  
F. Azpiroz ◽  
J. R. Malagelada
Keyword(s):  
Pressure Gradient ◽  
Phase I ◽  
Contractile Activity ◽  
External Pressure ◽  
Phase Iii ◽  
In Vivo Studies ◽  
Activity Phase ◽  
The Relationship

Changes in antroduodenal resistance to flow may participate in the regulation of gastric emptying and duodenogastric reflux. Little is known, however, about the relationship between antroduodenal resistance and the physiological patterns of contractile activity in this area. We have developed an instrument that maintains an electronically regulated constant-pressure gradient of 2 mmHg across both ends of a flaccid cylinder positioned fluoroscopically across the pylorus. Because resistance bears a constant inverse relationship to flow at a fixed pressure gradient, changes in the recorded rate of airflow through the cylinder are a measure of antroduodenal resistance. In vitro studies showed that, under these conditions, airflow was a function of the diameter and length of the air path and the frequency and duration of external pressure waves greater than 2 mmHg. In vivo studies in four dogs examined the relationship between interdigestive phases of motor activity and variations in resistance exerted by the antroduodenal area. We found that flow rates varied markedly with each phase. Antroduodenal resistance was lowest during motor quiescence (phase I), rose gradually during irregular activity (phase II), and reached its peak during maximal contractile activity (phase III) (P less than 0.05). Resistance was similar for antegrade and retrograde flow. Additional studies suggested that the pyloric area contributes mostly to resistance during phase I, whereas duodenal resistance at least matches that of the pylorus during phase III.

Motilin-independent ectopic fronts of the interdigestive myoelectric complex in dogs

1980 ◽  
Vol 239 (3) ◽  
pp. G215-G220 ◽  
Author(s):  
P. Poitras ◽  
J. H. Steinbach ◽  
G. VanDeventer ◽  
C. F. Code ◽  
J. H. Walsh
Keyword(s):  
Small Intestine ◽  
Conscious Dogs ◽  
Phase Iii ◽  
Entire Small Intestine ◽  
Meat Meal ◽  
The Relationship

We have studied in four conscious dogs the relationship between circulating concentrations of motilin and the activity front (phase III) of the interdigestive myoelectric complex. During fasting, cyclic peaks of motilin secretion were concomitant in every instance with the initiation of activity fronts that began in the stomach or duodenum. When somatostatin was administered at doses of 5, 2.5, or 0.625 microgram x kg-1 x h-1 for 3 h, motilin concentrations were stabilized at lowered levels and no activity fronts occurred in the duodenum. Somatostatin also inhibited the stimulatory effects of exogenous motilin on the entire small intestine. During somatostatin infusion, however, ectopic fronts began in the jejunum and were propagated to the cecum despite low motilin concentration. After a 100-g meat meal, the cyclic increase of motilin was interrupted and no activity fronts were observed in the duodenum, but ectopic fronts started lower in the small intestine. Our study supports the hypothesis that motilin induces activity fronts in the canine duodenum, but it shows that ectopic fronts are not controlled by motilin.

scholarly journals Evaluation of changes in gastrointestinal motility caused by altered thyroid function in conscious dogs

2021 ◽  
Author(s):  
Nobuhiro Nakazawa ◽  
Makoto Sohda ◽  
Kyoichi Ogata ◽  
Seded Baatar ◽  
Yasunari Ubukata ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Motor Activity ◽  
Thyroid Function ◽  
Gastrointestinal Motility ◽  
Gastrointestinal Hormones ◽  
Conscious Dogs ◽  
High Dose ◽  
Interdigestive Migrating Contractions ◽  
The Relationship ◽  
Upper Gastrointestinal

Abstract This study was conducted to clarify the relationship between thyroid function and gastrointestinal motility. We established an experimental configuration in which the feedback of thyroid function was completely removed using conscious dogs. With hypothyroidism, time of phase Ⅰ of interdigestive migrating contractions (IMC) was longer, time of phase Ⅱ and phase Ⅲ was significantly shortened, and both the continuous time of strong tetanic contraction at antrum and 10-hours frequency of phase Ⅲ counted from the first IMC after meal significantly decreased. Whereas, hyperthyroidism caused the opposite events to those with hypothyroidism. Furthermore, We found giant migrating contractions (GMC) occurred from the upper gastrointestinal tract when we administrated high dose of thyroid hormone. One GMC occurred from anal sides propagated to cardiac, and this propagation was similar to the emesis-like interdigestive motor activity, the other GMC occurred from oral sides propagated to anal sides and this was similar to the diarrhea-like interdigestive motor activity. We examined the relationship between thyroid function and gastrointestinal hormones including of ghrelin, GLP-1, and cholecystokinin (CCK). However, we could not find significant differences under different thyroid hormone status. This is the first report that thyroid hormone activated upper gastrointestinal motility without mediating gastrointestinal hormones.

scholarly journals Thyroid hormone activated upper gastrointestinal motility without mediating gastrointestinal hormones in conscious dogs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nobuhiro Nakazawa ◽  
Makoto Sohda ◽  
Kyoichi Ogata ◽  
Seded Baatar ◽  
Yasunari Ubukata ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Motor Activity ◽  
Thyroid Function ◽  
Gastrointestinal Motility ◽  
Gastrointestinal Hormones ◽  
Conscious Dogs ◽  
Phase Iii ◽  
High Dose ◽  
The Relationship ◽  
Upper Gastrointestinal

AbstractThis study was conducted to clarify the relationship between thyroid function and gastrointestinal motility. We established an experimental configuration in which the feedback of thyroid function was completely removed using conscious dogs. With hypothyroidism, time of phase I of interdigestive migrating contractions (IMC) was longer, time of phase II and phase III was significantly shortened, and both the continuous time of strong tetanic contraction at antrum and 10-h frequency of phase III counted from the first IMC after meal significantly decreased. Whereas, hyperthyroidism caused the opposite events to those with hypothyroidism. Furthermore, We found giant migrating contractions (GMC) occurred from the upper gastrointestinal tract when we administrated high dose of thyroid hormone. One GMC occurred from anal sides propagated to cardiac, and this propagation was similar to the emesis-like interdigestive motor activity, the other GMC occurred from oral sides propagated to anal sides and this was similar to the diarrhea-like interdigestive motor activity. We examined the relationship between thyroid function and gastrointestinal hormones including of ghrelin, GLP-1, and cholecystokinin (CCK). However, we could not find significant differences under different thyroid hormone status. This is the first report that thyroid hormone activated upper gastrointestinal motility without mediating gastrointestinal hormones.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Do Extra-Platelet Sources Contribute to the Plasma Level of Thrombospondin?

1988 ◽  
Vol 59 (02) ◽  
pp. 273-276 ◽  
Author(s):  
J Dawes ◽  
D A Pratt ◽  
M S Dewar ◽  
F E Preston
Keyword(s):  
Platelet Count ◽  
Background Concentration ◽  
Serum Concentrations ◽  
Bone Marrow Depression ◽  
Serial Sampling ◽  
Control Serum ◽  
Platelet Release ◽  
Highly Correlated ◽  
The Relationship

SummaryThrombospondin, a trimeric glycoprotein contained in the platelet α-granules, has been proposed as a marker of in vivo platelet activation. However, it is also synthesised by a range of other cells. The extraplatelet contribution to plasma levels of thrombospondin was therefore estimated by investigating the relationship between plasma thrombospondin levels and platelet count in samples from profoundly thrombocytopenic patients with marrow hypoplasia, using the platelet-specific α-granule protein β-thromboglobulin as control. Serum concentrations of both proteins were highly correlated with platelet count, but while plasma β-thromboglobulin levels and platelet count also correlated, there was no relationship between the number of platelets and thrombospondin concentrations in plasma. Serial sampling of patients recovering from bone marrow depression indicated that the plasma thrombospondin contributed by platelets is superimposed on a background concentration of at least 50 ng/ml probably derived from a non-platelet source, and plasma thrombospondin levels do not simply reflect platelet release.

Dose Requirement for Replacement Therapy in Hemophilia A

1979 ◽  
Vol 42 (03) ◽  
pp. 825-831 ◽  
Author(s):  
Jean-Pierre Allain
Keyword(s):  
Clinical Effect ◽  
Hemophilia A ◽  
Clinical Results ◽  
Severe Hemophilia ◽  
Dose Requirement ◽  
Viii Level ◽  
The Relationship ◽  
In Vivo Recovery ◽  
Different Doses

SummaryIn order to determine the correlation between different doses of F. VIII and their clinical effect,. 70 children with severe hemophilia A were studied after treatment with single doses of cryoprecipitate. The relationship between plasma F. VIII levels or doses calculated in u/ kg of body weight and clinical results followed an exponential curve. Plasma F. VIII levels of 0.35 and 0.53 u/ml corresponded to 95 and 99% satisfactory treatment, respectively. Similar clinical results were obtained with 20 and 31 u/kg. When the in vivo recovery of F. VIII after lyophilized cryoprecipitate was 0.015 u/ml for each u/kg injected, plasma F. VIII levels of 0.30 and 0.47 u/ml respectively were achieved. Since home treatment is largely based on single infusions of F. VIII, it is suggested that moderate and severe hemorrhages be treated with a dose which will provide a plasma F. VIII level of 0.5 u/ml.

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