The Role of Cholecystokinin 1 Receptor in Prolactin Inhibited Gastric Emptying of Male Rat

BACKGROUND/AIMS: Prolactin (PRL) is essential for the lactating mammals, while cholecystokinin (CCK) does inhibit gastric emptying (GE). Present study attempted to determine whether both peptides interacted on the male rat GE, particularly the role of putative CCK1 receptor. METHODS: Acute hyperprolactinemia of male rats was induced by the intraperitoneal injection of ovine PRL (oPRL) in several divided doses 15 minutes before motility study. Rat chronic hyperprolactinemia was induced by the graft of 2 pituitary glands into the capsule of left kidney, while control rats received cerebral cortex graft only. Motility study was conducted 6 weeks later after graft surgery. Fifteen minutes after the intragastric feeding of radiochromium, rat was sacrificed to measure GE via the distribution of radioactivities within stomach and intestine. Among the CCK1 receptor blocking study using lorglumide, rats were divided to receive the regimens in terms of oPRL-vehicle plus lorglumide-vehicle, oPRL plus lorglumide-vehicle, oPRL-vehicle plus lorglumide and oPRL plus lorglumide. Plasma CCK level was measured using a homemade radioimmunoassay kit. RESULTS: Compared to vehicle treatment, acute hyperprolactinemic rats under highest dose (2.0 mg/kg) of oPRL treatment showed delayed GE (70.6% +/- 3.0% vs 42.1% +/- 6.6%, P < 0.05). Chronic hyperprolactinemic rats under graft surgery also showed inhibited GE (70.5% +/- 1.7% vs 54.5% +/- 4.7%, P < 0.05). Both models finally obtained elevated plasma CCK levels (P < 0.05). Lorglumide itself did not influence GE, however, delayed GE under oPRL treatment was restored following the concomitant lorglumide treatment. CONCLUSIONS: Our study suggests that PRL may delay male rat GE via a mechanism of endogenous CCK activation involving the peripheral CCK1 receptor.

The Evaluation of Otilonium Bromide Treatment in Asian Patients With Irritable Bowel Syndrome

BACKGROUND/AIMS: Antispasmodics including otilonium bromide (OB) are recommended to treat irritable bowel syndrome (IBS). However, reports about OB experience in Asia is sparse. The purpose of present study was to provide the efficacy of OB in treating Asian IBS patients. METHODS: Overall, 117 IBS patients meeting Rome II criteria were enrolled in an 8-week, double-blind, active-controlled and single center trial. Randomized participants received either OB 40 mg or mebeverine 100 mg 3 doses daily. The primary endpoints were to evaluate the net changes of abdominal pain/discomfort frequency score (APDFS) and safety profile, while the secondary endpoints were to assess the changes in abdominal pain/discomfort intensity, flatulence, abdominal bloating, satisfied stool frequency etc. RESULTS: Finally, 49 OB and 52 mebeverine subjects were eligible for efficacy analysis. Compared to baselines in per protocol populations, the reduced APDFSs in OB and mebeverine were 0.55 +/- 1.20 (P = 0.011) and 0.37 +/- 1.11 (P = 0.042), respectively, to show similarly reduced scores. The most reported side effects included dry mouth, nausea and dizziness. Besides, the improved APDFSs at 4th week visit, final alleviations in abdominal pain intensity, flatulence, abdominal bloating and satisfied stool frequency with global assessments filled by both patients and investigators were significantly achieved by both treatments, and OB was not inferior to mebeverine in treating these parameters. CONCLUSIONS: In Orientals, OB is as effective as mebeverine for alleviating IBS symptoms in terms of abdominal pain, flatulence, abdominal bloating etc. However, obvious side effects are also observed. A large-scaled trial and post-marketing surveillance are recommended to confirm its efficacy and safety.

The Current Prevalence of Irritable Bowel Syndrome in Asia

Irritable bowel syndrome (IBS) has been one of the commonly presented gastrointestinal disorders. It is of interest how commonly it presents in the society. Western studies indicated that most population-based IBS prevalences range 10%-15%. It is believed that IBS is prevalent in both East and West countries without a significant prevalence difference. Most recently, the Asia IBS prevalence has a higher trend in the affluent cities compared to South Asia. Since many Asia IBS prevalence studies have been published in the recent decade, we could compare the IBS prevalence data divided by various criteria in looking whether they were also comparable to this of West community. Summarized together, most Asia community IBS prevalences based on various criteria are usually within the range 1%-10% and are apparently lower than these of selected populations. Within the same population, the prevalence orders are first higher based on Manning criteria, then followed by Rome I criteria and finally reported in Rome II criteria. Overall, the median value of Asia IBS prevalences defined by various criteria ranges 6.5%-10.1%. With regard to gender difference, female predominance is usually found but not uniquely existed. For the IBS subtypes, the proportions of diarrhea predominant-IBS distribute widely from 0.8% to 74.0%, while constipation predominant-IBS proportion ranges 12%-77%. In conclusions, current Asia IBS prevalence is at least equal to the Western countries. Female predominant prevalence in Asia is common but not uniquely existed, while the proportions of IBS subtypes are too variable to find a rule.