Effects of gastric pacing on gastric emptying and plasma motilin

AIM:To investigate the effects of gastric pacing on gastricemptying and plasma motilin level in a canine model of gastricmotility disorders and the correlation between gastricemptying and plasma motilin level.METHODS:Ten healthy Mongrel dogs were divided into:experimental group of six dogs and control group of fourdogs.A model of gastric motility disorders was establishedin the experimental group undergone truncal vagotomycombined with injection of glucagon.Gastric half-emptyingtime (GEt_(1/2)) was monitored with single photon emissioncomputerized tomography (SPECT),and the half-solid testmeal was labeled with an isotope-~(99m)mTc sulfur colloid.Plasmamotilin concentration was measured with radioimmunoassay(RIA) kit.Surface gastric pacing at 1.1-1.2 times the intrinsicslow-wave frequency and a superimposed series of highfrequency pulses (10-30 Hz) was performed for 45 rnin dailyfor a month in conscious dogs.RESULTS:After surgery,GEt_(1/2) in dogs undergone truncalvagotomy was increased significantly from 56.35±2.99 minto 79.42±1.91 rain (P<0.001),but surface gastric pacingmarkedly accelerated gastric emptying and significantlydecreased GEt_(1/2) to 64.94 1.75 min (P<0.001) in animalsundergone vagotomy.There was a significant increase ofplasma level of motilin at the phase of IMCⅢ(interdigestivemyoelectrical complex,IMCⅢ) in the dogs undergone bilateraltruncal vagotomy (baseline vsvagotomy,184.29±9.81 pg/mlvs 242.09±17.22 pg/ml;P<0.01).But plasma motilinconcentration (212.55±11.20 pg/ml;P<0.02) was decreasedsignificantly after a long-term treatment with gastric pacing.Before gastric pacing,GEt_(1/2) and plasma motilin concentrationof the dogs undergone vagotomy showed a positivecorrelation (r=0.867,P<0.01),but after a long-term gastricpacing,GEt_(1/2) and motilin level showed a negative correlation(r=-0.733,P<0.04).CONCLUSION:Surface gastric pacing with optimal pacingparameters can improve gastric emptying parameters andsignificantly accelerate gastric emptying and can resumeor alter motor function in a canine model of motilitydisorders.Gastric emptying is correlated well with plasmamotilin level before and after pacing,which suggests that motilin can modulate the mechanism of gastric pacing byaltering gastric motility.     

Does antecolic reconstruction decrease delayed gastric emptying after pancreatoduodenectomy?

Delayed gastric emptying (DGE) is a frequent complication after pylorus-preserving pancreatoduodenectomy (PpPD). Kawai and colleagues proposed pylorus-resecting pancreatoduodenectomy (PrPD) with antecolic gastrojejunal anastomosis to obviate DGE occurring after PpPD. Here we debate the reported differences in the prevalence of DGE in antecolic and retrocolic gastro/duodeno-jejunostomies after PrPD and PpPD, respectively. We concluded that the route of the gastro/duodeno-jejunal anastomosis with respect to the transverse colon; i.e., antecolic route or retrocolic route, is not responsible for the differences in prevalence of DGE after pancreatoduodenectomy (PD) and that the impact of the reconstructive method on DGE is related mostly to the angulation or torsion of the gastro/duodeno-jejunostomy. We report a prevalence of 8.9% grade A DGE and 1.1% grade C DGE in a series of 89 subtotal stomach-preserving PDs with Roux-en Y retrocolic reconstruction with anastomosis of the isolated Roux limb to the stomach and single Roux limb to both the pancreatic stump and hepatic duct. Retrocolic anastomosis of the isolated first jejunal loop to the gastric remnant allows outflow of the gastric contents by gravity through a “straight route”.     

Are there changes in gastric emptying during the menstrual cycle?

BACKGROUND: The questions of whether gastric emptying of solids and liquids differs in men and women and whether emptying is influenced by the action of sex hormones on gastric smooth muscle remain unresolved. METHODS: We analysed the gastric emptying of digestible solids (GES), liquids (GEL), and radiopaque indigestible solids (GER) in three groups of healthy volunteers: 50 women in the follicular phase of the menstrual cycle, 50 women in the luteal phase, and 100 men. [99mTc]-labelled diethylenetriamine pentaacetic acid (DTPA) was used as the radioactive marker for digestible solids, and [111In]DTPA was used as the marker for liquids, to time gastric motility after a solid and a liquid meal. GER was evaluated on a different day in abdominal roentgenograms. RESULTS: GES and GEL were slower in women than in men (P < 0.05), but GER was similar in the two sexes. However, there were no significant differences in GES, GEL, or GER between women in the follicular and those in the luteal phase, between plasma concentrations of oestradiol and progesterone and the variables used to characterize gastric emptying. CONCLUSIONS: Evidence of postprandial 'physiologic gastroparesis' was found in women, although no differences were found between men and women in gastric motility during fasting. The rate of emptying was not related to changes in plasma concentrations of sex hormones during the menstrual cycle.     

Effects of Helicobacterpyloriinfection on gastric emptying rate in patients with non-ulcer dyspepsia

AIM:The pathogenesis of delayed gastric emptying inpatients with non-ulcer dyspepsia(NUD)remains unclear.We aimed to examine whether gastric emptying rate inNUD patients was associated with Helicobacter pylori(Hpylori)infection and whether it was affected by eradication ofthe infection.METHODS:Gastric emptying rate of a mixed solid-liquidmeal was assessed by the paracetamol absorption methodin NUD patients and asymptomatic controls(n=17).Hpyloristatus was assessed by serology and biopsy urease test.H pylori-positive NUD patients(n=23)received 10-day tripleeradication therapy.Hpyloristatus was re-assessed bybiopsy urease test four weeks later,and if eradication wasconfirmed,gastric emptying rate was re-evaluated.RESULTS:Thirty-three NUD patients and 17 controls wereevaluated.NUD patients had significantly delayed gastricemptying compared with controls.The mean maximumplasma paracetamol concentration divided by body mass(Cmax/BM)was 0.173 and 0.224 mg/L.kg respectively(P=0.02),the mean area under plasma paracetamolconcentration-time curve divided by body mass(AUC/BM)was 18.42 and 24.39 mg.min/L.kg respectively(P=0.01).Gastric emptying rate did not differ significantly betweenH pylori-positive and H pylori-negative NUD patients.Themean Cmax/BM was 0.172 and 0.177 mg/L·kg respectively(P=0.58),the mean AUC/BM was 18.43 and 18.38 mg·min/L·kg respectively(P=0.91).Among 14 NUD patients whowere initially H pylori-positive,confirmed eradication ofthe infection did not significantly alter gastric emptying rate.The mean Cmax/BM was 0.171 and 0.160 mg/L.kg beforeand after Hp eradication,respectively(P=0.64),the meanAUC/BM was 17.41 and 18.02 mg.min/L.kg before and aftereradication,respectively(P=0.93).CONCLUSION:Although gastric emptying is delayed in NUD patients compared with controls,gastric emptying rate isnot associated with H pylori status nor it is affected byeradication of the infection.     

Is delayed gastric emptying so terrible after pylorus-preserving pancreaticoduodenectomy？ Prevention and management

INTRODUCTION Pylorus-preserving pancreaticoduodenectomy (PPPD) was first reported by Watson in 1944[1] and reintroduced by Traverso and Longmire in 1978[2]. For the sake of functional preservation of the stomach and improvement of life quality, it has bee…     

Can symptoms discriminate among those with delayed or normal gastric emptying in dysmotility-like dyspepsia?

OBJECTIVE: Different subgroups can be identified in functional dyspepsia based on symptom type or severity, and may correlate with pathophysiological disturbances. In particular, female sex and severe fullness and vomiting have been reported to be strong independent predictors of slow solid gastric emptying. We aimed to determine if symptom patterns or severity could identify those with abnormal gastric emptying among patients with dysmotility-like functional dyspepsia and, for comparison, type I diabetes mellitus. METHODS: Patients with postprandial symptoms and documented functional dyspepsia by endoscopy (n = 551) and patients with type I diabetes who had postprandial dyspepsia (n = 247) enrolling in two separate randomized controlled trials were evaluated at baseline. Patients were assigned to either the delayed or normal gastric emptying strata, based on a validated C13 octanoic acid breath test with sampling over 4 h. A self-report questionnaire measured the presence and severity of eight symptoms on visual analog scales. The validated Nepean Dyspepsia Index measured the frequency, severity, and bothersomeness of 15 upper GI symptoms on Likert scales. RESULTS: Gastric emptying was definitely delayed (t1/2 > 192 min) in 24% of patients with functional dyspepsia and 28% with diabetes. Delayed gastric emptying was associated with female gender but not age or Helicobacter pylori status. The age- and sex-adjusted risk (odds ratio) of delayed gastric emptying for the upper GI symptoms ranged from 0.99 to 1.0 (all p values > or =0.2). The results were very similar in functional dyspepsia and diabetes. There was also no correlation between t1/2 and number of symptoms or symptom severity scores. CONCLUSIONS: Symptom prevalence and severity were similar in dyspeptic patients with and without delayed gastric emptying. Specific symptoms do not seem to be of predictive value in dysmotility-like dyspepsia for identifying alterations of gastric emptying.     

Does delayed gastric emptying shorten the H pylori eradication period？ A double blind clinical trial

INTRODUCTION H pylori has been implicated as a predisposing factor in gastric cancer, chronic active gastritis, duodenal ulcer, gastric ulcer and gastric lymphoma[1]. The incidence rate of stomach cancer in Iran is high, well above the world average; it i…     

Impaired gastric emptying and altered intragastric meal distribution in diabetes mellitus related to autonomic neuropathy?

Previous studies in diabetic patients suggested a relationship between delayed gastric emptying and increased ingesta retention in either proximal or distal stomach, but the determinants underlying these abnormalities remained obscure. We aimed at assessing the impact of cardiovascular autonomic neuropathy, blood glucose concentration, long-term glycemic control, and other factors in 34 type I and 43 type II diabetic patients (ages 21–67 and 34–81 years, respectively). Emptying was slower (P < 0.04) in type I diabetic patients than in 20 healthy control subjects (ages 23–63 years). Patients with autonomic neuropathy (N = 45) had slower gastric emptying (P < 0.02) and retained more in the distal stomach (P < 0.0001) than patients without neuropathy (N = 32). Multiple regression analyses revealed that slow emptying and increased distal retention were significantly associated with autonomic neuropathy (P < 0.043, P < 0.0002), whereas blood glucose, glycemic control, diabetes duration, age, and other factors had no discernible influence. Thus, both slow emptying and increased distal ingesta retention seem primarily referable to autonomic neuropathy.     

Does antecolic reconstruction for duodenojejunostomy improve delayed gastric emptying after pylorus-preserving pancreaticoduodenectomy? A systematic review and meta-analysis

AIM: To evaluate whether antecolic reconstruction for duodenojejunostomy (DJ) can decrease delayed gastric emptying (DGE) rate after pylorus-preserving pancreaticoduodenectomy (PPPD) through literature review and meta-analysis.METHODS: Articles published between January 1991 and April 2012 comparing antecolic and retrocolic reconstruction for DJ after PPPD were retrieved from the databases of MEDLINE (PubMed), EMBASE, OVID and Cochrane Library Central. The primary outcome of interest was DGE. Either fixed effects model or random effects model was used to assess the pooled effect based on the heterogeneity.RESULTS: Five articles were identified for inclusion: two randomized controlled trials and three non-randomized controlled trials. The meta-analysis revealed that antecolic reconstruction for DJ after PPPD was associated with a statistically significant decrease in the incidence of DGE [odds ratio (OR), 0.06; 95% CI, 0.02-0.17; P < 0.00 001] and intra-operative blood loss [mean difference (MD), -317.68; 95% CI, -416.67 to -218.70; P < 0.00 001]. There was no significant difference between the groups of antecolic and retrocolic reconstruction in operative time (MD, 25.23; 95% CI, -14.37 to 64.83; P = 0.21), postoperative mortality, overall morbidity (OR, 0.54; 95% CI, 0.20-1.46; P = 0.22) and length of postoperative hospital stay (MD, -9.08; 95% CI, -21.28 to 3.11; P = 0.14).CONCLUSION: Antecolic reconstruction for DJ can decrease the DGE rate after PPPD.     

Bitter taste receptors and α-gustducin regulate the secretion of ghrelin with functional effects on food intake and gastric emptying

Ghrelin is a hunger hormone with gastroprokinetic properties but the factors controlling ghrelin secretion from the stomach are unknown. Bitter taste receptors (T2R) and the gustatory G proteins, α-gustducin (gust) and α-transducin, are expressed in the gut and are involved in the chemosensation of nutrients. This study aimed to investigate whether T2R-agonists affect (i) ghrelin release via α-gustducin and (ii) food intake and gastric emptying via the release of ghrelin. The mouse stomach contains two ghrelin cell populations: cells containing octanoyl and desoctanoyl ghrelin, which were colocalized with α-gustducin and α-transducin, and cells staining for desoctanoyl ghrelin. Gavage of T2R-agonists increased plasma octanoyl ghrelin levels in WT mice but the effect was partially blunted in gust(-/-) mice. Intragastric administration of T2R-agonists increased food intake during the first 30 min in WT but not in gust(-/-) and ghrelin receptor knockout mice. This increase was accompanied by an increase in the mRNA expression of agouti-related peptide in the hypothalamus of WT but not of gust(-/-) mice. The temporary increase in food intake was followed by a prolonged decrease (next 4 h), which correlated with an inhibition of gastric emptying. The delay in emptying, which was partially counteracted by ghrelin, was not mediated by cholecystokinin and GLP-1 but involved a direct inhibitory effect of T2R-agonists on gastric contractility. This study is unique in providing functional evidence that activation of bitter taste receptors stimulates ghrelin secretion. Modulation of endogenous ghrelin levels by tastants may provide novel therapeutic applications for the treatment of weight -and gastrointestinal motility disorders.     

Use of the alpha-glucosidase inhibitor acarbose in patients with ‘Middleton syndrome’: Normal gastric anatomy but with accelerated gastric emptying causing postprandial reactive hypoglycemia and diarrhea

Postprandial reactive hypoglycemia, early satiety and diarrhea are well-recognized side effects following full or partial gastrectomy or gastric bypass. It has only recently been realized, however, that patients with normal gastric anatomy may experience similar symptoms and signs due to primary accelerated gastric emptying (Middleton syndrome). In previous case studies, patients responded well to the use of dietary modification (frequent small-volume meals) alone. The authors describe two patients with this syndrome who continued to experience symptoms of reactive postprandial hypoglycemia despite dietary intervention but became asymptomatic following the addition of the alpha-glucosidase inhibitor acarbose.