Stimulating effects of KW-5092, a novel gastroprokinetic agent, on the gastric emptying, small intestinal propulsion and colonic propulsion in rats

The Use of Pre-Endoscopic Metoclopramide Does Not Prevent the Need for Repeat Endoscopy: A U.S. Based Retrospective Cohort Study

BACKGROUND

Peptic ulcer disease (PUD) can cause upper gastrointestinal bleeding (UGIB), often needing esophagogastroduodenoscopy (EGD). Second-look endoscopies verify resolution, but cost concerns prompt research on metoclopramide's efficacy compared to erythromycin.

METHODS

We analyzed the Diamond Network of TriNetX Research database, dividing UGIB patients with PUD undergoing EGD into three groups: metoclopramide, erythromycin, and no medication. Using 1:1 propensity score matching, we compared repeat EGD, post-EGD transfusion, and mortality within one month in two study arms.

RESULTS

Out of 97,040 patients, 11.5% received metoclopramide, 3.9% received erythromycin, and 84.6% received no medication. Comparing metoclopramide to no medication showed no significant difference in repeat EGD (10.1% vs. 9.7%, p = 0.34), transfusion (0.78% vs. 0.86%, p = 0.5), or mortality (1.08% vs. 1.08%, p = 0.95). However, metoclopramide had a higher repeat EGD rate compared to erythromycin (9.4% vs. 7.5%, p = 0.003), with no significant difference in transfusion or mortality.

CONCLUSIONS

The need to repeat EGD was not decreased with pre-EGD use of metoclopramide. If a prokinetic agent is to be used prior to EGD, erythromycin shows superior reduction in the need of repeat EGD as compared to metoclopramide.

Interaction of insulin with prokinetic drugs in STZ-induced diabetic mice

AIM: To study the possible interactions of metoclopramide, domperidone and erythromycin in streptozotocin-induced diabetic mice treated with insulin by various parameters.

METHODS: Effects of the individual as well as combined drugs were studied in diabetic mice via estimation of the blood glucose and serum insulin levels, small intestinal transit (SIT), gastric emptying (GE), xylose absorption and glucose tolerance tests. Groups were given insulin 2 IU/kg s.c., metoclopramide 20 mg/kg p.o., domperidone 20 mg/kg p.o. and erythromycin 6 mg/kg p.o. individually and in combination. There were also normal and diabetic control groups. The first set of experiments was carried out to investigate the subchronic effect on blood glucose and serum insulin levels in diabetic mice of one week of daily dose administration of the tested drugs individually as well as the combination of insulin with each prokinetic drug. The other five sets of experiments were carried out to investigate the acute effect of a single dose of each drug individually and in combination on blood glucose and serum insulin levels, SIT, GE, oral xylose absorption and glucose tolerance tests.

RESULTS: The study included the prokinetic drugs metoclopramide (20 mg/kg), domperidone (20 mg/kg) and erythromycin (6 mg/kg), as well as insulin (2 IU/kg), which was individually effective in decreasing SIT, enhancing GE and increasing xylose absorption significantly in diabetic mice. Erythromycin tended to decrease blood glucose level and increase serum insulin level after 1 wk of daily administration in diabetic mice. Erythromycin potentiated the effect of insulin on blood glucose level and serum insulin level whereas other prokinetic agents failed to do so after repeated dose administration in diabetic mice. Metoclopramide or erythromycin in combination with insulin significantly decreased SIT, in diabetic mice, to lower levels than with insulin alone. Administration of prokinetic drugs along with insulin antagonized the action of insulin on xylose absorption. These combinations also increased the rate of glucose absorption from the gut.

CONCLUSION: The present study suggests that prokinetic drugs could potentially improve glycemic control in diabetic gastroparesis by allowing a more predictable absorption of nutrients, matched to the action of exogenous insulin. The use of prokinetics, such as erythromycin, may be interesting in the clinic in decreasing the need for insulin in diabetic patients. The dose of insulin may be safely decreased with erythromycin in chronic treatments.

Metoclopramide in the treatment of diabetic gastroparesis

Gastroparesis is a chronic disorder that affects a significant subset of the population. Diabetes mellitus is a risk factor for the development of gastroparesis. Currently, metoclopramide is the only US FDA-approved medication for the treatment of gastroparesis. However, the FDA recently placed a black-box warning on metoclopramide because of the risk of related side effects, including tardive dyskinesia, the incidence of which has been cited to be as high as 15% in the literature. This review will investigate the mechanisms by which metoclopramide improves the symptoms of gastroparesis and will focus on the evidence of clinical efficacy supporting metoclopramide use in gastroparesis. Finally, we seek to document the true complication risk from metoclopramide, especially tardive dyskinesia, by reviewing the available evidence in the literature. Potential strategies to mitigate the risk of complications from metoclopramide will also be discussed.

A novel method for the evaluation of intestinal transit and contractility in mice using fluorescence imaging and spatiotemporal motility mapping

This study introduces a novel, simplified method for the evaluation of murine intestinal transit and contractility using fluorescence and video imaging. Intestinal transit was measured by evaluating the intestinal distribution of non-absorbable fluorescein-labelled dextran (70 kDa, FD70) along the gastrointestinal (GI) tract. After excision of the GI tract, two full-field images--one in normal illumination mode and another in fluorescent mode--were taken with a charge coupled device (CCD) camera and subsequently matched for calculation of fluorescence distribution along the GI tract. Immediately after, intestinal contractility was evaluated in different regions of the intact intestine by spatiotemporal motility mapping (i.e. video imaging). In control mice, the small intestine showed vigorous oscillatory contractions and FD70 was primarily distributed within the terminal ileum/caecum at 90 min postgavage. As validation step, the effect of intestinal manipulation (IM, surgical procedure) and two pharmacological agents--known to alter GI motility--was tested. At 24 h postoperatively, spontaneous contractile activity of the small intestine was nearly abolished in IM mice, leaving the small intestine distended and resulting in a significantly delayed intestinal transit. In accordance, spontaneous mechanical activity of circular muscle strips in standard organ baths was significantly reduced in IM mice compared to control mice. Administration of atropine (1-3 mg kg(-1), i.p.) suppressed spontaneous contractile activity along the entire intestinal tract and induced a dose-related delay in intestinal transit. In contrast, metoclopramide (3-10 mg kg(-1), i.p.) markedly increased contractile activity--however only in the upper GI tract--and accelerated intestinal transit in a dose-dependent manner.

Prokineticin-2, motilin, ghrelin and metoclopramide: prokinetic utility in mouse stomach and colon

The ability of agents described as gastrointestinal prokinetics (prokineticin-2, [Nle(13)]-motilin, ghrelin), to modulate nerve-mediated contractions of mouse isolated stomach and colon was determined and compared with the prokinetic and 5-HT(4) receptor agonist, metoclopramide. Circular muscle preparations were electrically field-stimulated (EFS) to evoke cholinergically mediated contractions. Metoclopramide 10-100 microM facilitated EFS-evoked contractions in forestomach (n = 5-11, P < 0.05); 1 mM inhibited. Metoclopramide had no effects in colon, apart from 100 microM which reduced contractions. Prokineticin-2 0.001 nM-0.1 microM (n = 3-7) or [Nle(13)]-motilin 0.1 nM-1 microM (n = 4-8) had no effects in forestomach or colon. Ghrelin 0.01-1 microM facilitated EFS-evoked contractions in forestomach (n = 5-7, P < 0.05) but not in colon (n = 5-8). We conclude that ghrelin and metoclopramide facilitate excitatory nerve activity because neither affected inhibitory responses to EFS in the presence of atropine, or contractions to carbachol. Further, prokineticin-2 and [Nle(13)]-motilin are unlikely to exert gastric prokinetic activity in this species, the inactivity of the latter being consistent with an absence of the motilin receptor in rodents.

KW-5092, a novel gastrokinetic agent, facilitates luminal serotonin release from the guinea-pig colon

The present study was designed to determine the influence of KW-5092 ((1-[2-[[[5-(piperidinomethyl)-2-furanyl]methyl]amino]ethyl]-2- imidazolidinylidene) propanedinitrile fumarate), a novel gastroprokinetic agent on intraluminal serotonin (5-hydroxytryptamine, 5-HT) release which reflects the release of 5-HT from enterochromaffin cells, using the luminally perfused isolated guinea-pig proximal colon in vitro. 5-HT was determined by high-performance liquid chromatography with electrochemical detection. KW-5092 (1-10 microM) concentration-dependently caused an increase in the luminal 5-HT outflow. In the presence of atropine (0.2 microM) or tetrodotoxin (0.3 microM), the stimulatory action of KW-5092 (10 microM) was inhibited by 94% and 74%, respectively. These results suggest that KW-5092 stimulates intraluminal 5-HT release from luminally perfused proximal colon of the guinea-pig via the stimulation of cholinergic neurons. Because 5-HT is recognized as an important messenger substance in the control of intestinal motility, this stimulatory effect could be considered as an indirect action of KW-5092 that may contribute to its prokinetic effects.

Effects of KW-5092 on antroduodenal coordination and gastric emptying in guinea-pigs

KW-5092 (2-[1-[2-[[5-(piperidinomethyl)-2-furanyl] methylamino]ethyl]imidazonylidin-2-ylidenene]malononitrile fumarate) is a novel gastroprokinetic agent with both acetylcholine release facilitatory and acetylcholinesterase inhibitory activity. We have investigated the effects of KW-5092 on antroduodenal coordination and gastric emptying in guinea-pigs. In the guinea-pig isolated gastroduodenal preparation, KW-5092 at 3 x 10(-7) to 3 x 10(-6) M significantly increased antroduodenal coordination. The effect of KW-5092 was almost completely inhibited by atropine or tetrodotoxin. Cisapride, a gastroprokinetic agent with acetylcholine release facilitatory activity, also increased coordination whereas neither acetylcholine nor the acetylcholinesterase inhibitor neostigmine affected it. In-vivo, KW-5092 and cisapride enhanced gastric emptying whereas neostigmine delayed it. These results suggest that acetylcholine release facilitation, but not acetylcholinesterase inhibition, is involved in the enhancement by KW-5092 of antroduodenal coordination and gastric emptying.

Does neostigmine have a deleterious effect on the resistance of colonic anastomoses?

The aim of the present study was to evaluate the effects of neostigmine as a final anaesthetic manoeuvre on colonic anastomoses. A colonic anastomosis was constructed in 40 Sprague-Dawley rats. The animals were divided into two groups: (1) rats receiving intravenous saline solution (placebo); and (2) rats receiving an intravenous injection of neostigmine. The size of the caecum, and the diameters of the pre-anastomotic and post-anastomotic colon were measured during the operation and 4 days after surgery, when all the animals were sacrificed. At this time, the presence of adhesions was also investigated. Each segment containing an anastomosis was removed, and the bursting pressure and bursting wall tension were determined. Loss of caecum diameter was significantly greater in group 2 than in group 1 (P = 0.03). Dilatation and obstruction of the colon were significantly more frequent in group 1 (dilatation, P = 0.01; obstruction, P = 0.047). Also, consumption of water by group 2 was greater than that by group 1 (P = 0.049). No statistically significant differences were found between the diameters of the colon (pre- and post-anastomosis), or with respect to general adhesions and adhesions to the anastomotic line. No significant differences were found between anastomotic resistance (determined in terms of bursting pressure and bursting wall tension) in the two groups. The inclusion of neostigmine in an anaesthetic protocol under experimental setting did not reduce the resistance of colonic anastomoses and did not compromise normal healing. Moreover, obstruction caused by peristaltic weakness might be prevented by the expulsion of stool that is induced by the strong contraction of the colonic smooth muscle.

Oral administration of KW-5092, a novel gastroprokinetic agent with acetylcholinesterase inhibitory and acetylcholine release enhancing activities, causes a dose-dependent increase in the blood acetylcholine content of beagle dogs

Acetylcholine (ACh) was detected in the blood and plasma of beagle dogs using a specific, sensitive radioimmunoassay. The mean basal ACh contents in the blood and plasma of beagle dogs were 451 +/- 65 and 83.5 +/- 12.3 pg/ml (+/- SEM, n = 7), respectively, and were lower than the contents in humans reported previously by our laboratory. Oral administration of KW-5092 (10-30 mg/kg), a gastroprokinetic agent with acetylcholinesterase (AChE) inhibitory and ACh release enhancing activities, caused a dose-dependent increase in the ACh content of both the blood and plasma, as well as several behavioral side effects due to peripheral cholinergic stimulation. The size of the increase in the plasma ACh content at each dose of KW-5092 was greater than that in the blood, indicating that KW-5092 caused the increase in the blood ACh content through elevation of the plasma ACh content, by inhibition of AChE and facilitation of ACh release. These results demonstrate that the blood ACh of beagle dogs is present mainly in the blood cells and to a lesser degree in the plasma, and that KW-5092 increased the blood ACh content mainly by increasing the plasma ACh concentration.

Compounds possessing 5-HT3 receptor antagonistic activity inhibit intestinal propulsion in mice

The role of 5-HT3 receptors in the control of intestinal propulsive activity was investigated in mice by a simple method in which the time taken for excretion of the head of an orally administered non-absorbable marker (whole gut transit time) was measured. Selective 5-HT3 receptor antagonists ramosetron (YM060) at 0.01-0.3 mg/kg s. c. and ondansetron at 0.1-1 mg/kg s.c. dose-dependently prolonged the whole gut transit time. Prokinetic benzamides, such as renzapride (0.3-10 mg/kg s.c.), zacopride (0.01-0.3 mg/kg s.c.) and cisapride (0.1-3 mg/kg s.c.), which have been reported to possess 5-HT3 receptor blocking properties, also dose-dependently prolonged it. These results indicate that activation of 5-HT3 receptors seems to be one factor that underlies the physiological control of intestinal propulsive activity in mice. In contrast to their beneficial therapeutic effects on gastroduodenal dysmotility, prokinetic benzamides, at least those which have 5-HT3 receptor antagonistic activity, may be unsuitable in the treatment of impaired lower intestinal propulsive activity.

KW-5092, a novel gastroprokinetic agent, reverses the norepinephrine-induced decline of the gastric mucosal blood flow in rats

We examined the effects of KW-5092 ((1-[2-[[[5-(piperidinomethyl)-2-furanyl]methyl]-amino]ethyl]- 2-imidazolidinylidene) propanedinitrile fumarate), a novel gastroprokinetic agent, on gastric mucosal blood flow (GMBF) in anesthetized rats. Intravenous infusion of KW-5092 (0.1 mg/kg/min for 30 min), which did not affect the basal GMBF, reversed the norepinephrine (1 microgram/kg/min, i.v. infusion for 30 min)-induced decline of GMBF in the corpus and the antrum. The improvement by KW-5092 of the GMBF was abolished by atropine (0.1 mg/kg/min, i.v. infusion for 30 min). These results suggest that KW-5092, via cholinergic activation, could counteract the decline of GMBF induced by adrenergic activation.