Exploring the role of neurogenic pathway-linked cholecystokinin release in remote preconditioning-induced cardioprotection

Abstract Purpose: The current study explored the involvement of neurogenic pathway-linked cholecystokinin (CCK) release in RIP-induced cardioprotection in rats. Methods: Male Wistar rats were subjected to four cycles of alternate episodes of ischemia and reperfusion (five min each) to induce RIP. Thereafter, the hearts were subjected to global ischemia and reperfusion ex vivo. The myocardial damage was assessed by quantifying the levels of heartspecific biochemicals i.e. LDH-1, CK-MB and cTnT. Apoptotic cell injury was assessed by measuring the levels of caspase-3 and Bcl-2. The levels of CCK were measured in the plasma following RIP. Results: Exposure to RIP significantly increased the plasma levels of CCK and attenuated IR-induced myocardial injury. Administration of CCK antagonist, proglumide significantly attenuated RIP-induced cardioprotection. Administration of hexamethonium, a ganglion blocker, abolished RIP-induced increase in plasma CCK levels and cardioprotective effects. Exogenous delivery of CCK-8 restored the effects of RIP in hexamethonium treated animals. Conclusion: RIP activates the neurogenic pathway that may increase the plasma levels of CCK, which may act on the heart-localized CCK receptors to produce cardioprotection against I/R injury.

Basal Forebrain Cholinergic-induced Activation of Cholecystokinin Inhibitory Neurons in the Basolateral Amygdala

The basolateral amygdala (BLA) receives dense projections from cholinergic neurons of the basal forebrain. Acetylcholine can contributes to amygdala-dependent behaviors: formation and extinction of fear memory and appetitive instrumental learning. However, the cholinergic mechanism at the circuit level has not been defined yet. We demonstrated that cholinergic-induced di-synaptic inhibition of BLA pyramidal neurons exhibits a retrograde form of short-term synaptic inhibition, depolarization-induced suppression of inhibition (DSI). Activation of nicotinic receptors was sufficient to evoke action potentials in cholecystokinin (CCK)-positive inhibitory neurons, which strongly inhibit pyramidal neurons through their perisomatic synapses. Our cell type-specific monosynaptic retrograde tracing also revealed that CCK neurons are innervated by basal forebrain cholinergic neurons. Therefore, our data indicated that CCK inhibitory neurons mediate the cholinergic-induced di-synaptic inhibition of BLA pyramidal neurons.

Effects of Intraduodenal Infusion of the Bitter Tastant, Quinine, on Antropyloroduodenal Motility, Plasma Cholecystokinin, and Energy Intake in Healthy Men

BACKGROUND/AIMS: Nutrient-induced gut hormone release (eg, cholecystokinin [CCK]) and the modulation of gut motility (particularly pyloric stimulation) contribute to the regulation of acute energy intake. Non-caloric bitter compounds, including quinine, have recently been shown in cell-line and animal studies to stimulate the release of gastrointestinal hormones by activating bitter taste receptors expressed throughout the gastrointestinal tract, and thus, may potentially suppress energy intake without providing additional calories. This study aims to evaluate the effects of intraduodenally administered quinine on antropyloroduodenal pressures, plasma CCK and energy intake. METHODS: Fourteen healthy, lean men (25 ± 5 years; BMI: 22.5 ± 2.0 kg/m²) received on 4 separate occasions, in randomized, double-blind fashion, 60-minute intraduodenal infusions of quinine hydrochloride at doses totaling 37.5 mg (“Q37.5”), 75 mg (“Q75”) or 225 mg (“Q225”), or control (all 300 mOsmol). Antropyloroduodenal pressures (high-resolution manometry), plasma CCK (radioimmunoassay), and appetite perceptions/gastrointestinal symptoms (visual analog questionnaires) were measured. Ad libitum energy intake (buffet-meal) was quantified immediately post-infusion. Oral quinine taste-thresholds were assessed on a separate occasion using 3-alternative forced-choice procedure. RESULTS: All participants detected quinine orally (detection-threshold: 0.19 ± 0.07 mmol/L). Intraduodenal quinine did not affect antral, pyloric or duodenal pressures, plasma CCK (pmol/L [peak]; control: 3.6 ± 0.4, Q37.5: 3.6 ± 0.4, Q75: 3.7 ± 0.3, Q225: 3.9 ± 0.4), appetite perceptions, gastrointestinal symptoms or energy intake (kcal; control: 1088 ± 90, Q37.5: 1057 ± 69, Q75: 1029 ±70, Q225: 1077 ± 88). CONCLUSION: Quinine, administered intraduodenally over 60 minutes, even at moderately high doses, but low infusion rates, does not modulate appetite-related gastrointestinal functions or energy intake.

Fatty meal sonography comparing coconut oil and chocolate bar with full-fat yoghurt as cholecystagogues for gallbladder ejection fractions

Background: The authors compared the effectiveness of a chocolate bar and full-fat yoghurt combination to coconut oil in determining the gallbladder ejection fraction (GBEF). The clinical motive was functional gallbladder disorder (FGD) which has the clinical picture of symptomatic gallstones but without gallstones. Functional gallbladder disorder has a decreased GBEF of less than 35%. Gallbladder ejection fraction can be calculated by ultrasound, using cholecystokinin (CCK) as a stimulant for gallbladder contraction. Cholecystokinin is not available in South Africa, and the researchers compared a 60 g Snickers chocolate bar with 200 g full-fat yoghurt, against the theoretically superior coconut oil. Objectives: To determine the efficacy of coconut oil versus chocolate bar and 200 g full-fat yoghurt combination in performing sonographic GBEFs. Method: This was a randomised clinical experiment, before and after crossover trial. The three experimental components of the study included 15 g coconut oil, 20 g coconut oil and a standard fatty meal consisting of 60 g Snickers bar and 200 g full-fat yoghurt. Results: The GBEF for the chocolate bar and yoghurt combination was the highest (62.84%). The GBEF for 20 g of coconut oil was 23.47% and for 15 g of coconut oil was 5.11%. There was a statistically significant difference between the chocolate and yoghurt combination and the 20g coconut oil, as well as the chocolate yoghurt combination and the 15 g coconut oil, both with a p-value of < 0.0001. No statistically significant difference was found between the 20 g and 15 g coconut oil. Conclusions: The 60 g Snickers chocolate bar and 200 g full-fat yoghurt combination was superior to the coconut oil. The authors advocate using the chocolate and yoghurt fatty meal oral stimulant to determine GBEF

Laminar Distribution of Neurochemically-Identified Interneurons and Cellular Co-expression of Molecular Markers in Epileptic Human Cortex / 神经科学通报·英文版

Inhibitory GABAergic interneurons are fundamental elements of cortical circuits and play critical roles in shaping network activity. Dysfunction of interneurons can lead to various brain disorders, including epilepsy, schizophrenia, and anxiety. Based on the electrophysiological properties, cell morphology, and molecular identity, interneurons could be classified into various subgroups. In this study, we investigated the density and laminar distribution of different interneuron types and the co-expression of molecular markers in epileptic human cortex. We found that parvalbumin (PV) and somatostatin (SST) neurons were distributed in all cortical layers except layer I, while tyrosine hydroxylase (TH) and neuropeptide Y (NPY) were abundant in the deep layers and white matter. Cholecystokinin (CCK) neurons showed a high density in layers IV and VI. Neurons with these markers constituted ~7.2% (PV), 2.6% (SST), 0.5% (TH), 0.5% (NPY), and 4.4% (CCK) of the gray-matter neuron population. Double- and triple-labeling revealed that NPY neurons were also SST-immunoreactive (97.7%), and TH neurons were more likely to express SST (34.2%) than PV (14.6%). A subpopulation of CCK neurons (28.0%) also expressed PV, but none contained SST. Together, these results revealed the density and distribution patterns of different interneuron populations and the overlap between molecular markers in epileptic human cortex.

Calcium-sensing receptor-mediated L-tryptophan-induced secretion of cholecystokinin and glucose-dependent insulinotropic peptide in swine duodenum

This study aimed to elucidate the effect of tryptophan (Trp) on gut hormone secretion as well as the roles of the calcium-sensing receptor (CaSR) and its downstream signaling pathway in gut hormone secretion by assessing swine duodenal perfusion in vitro. Swine duodenum was perfused with Krebs-Henseleit buffer as a basal solution. Various concentrations (0, 10, and 20 mM) of Trp were applied to investigate its effect on gut hormone secretion. A CaSR antagonist was used to detect the involvement of CaSR and its signal molecules. The 20 mM Trp concentration promoted the secretion of cholecystokinin (CCK) and glucose-dependent insulinotropic peptide (GIP), elevated the mRNA level of CaSR, and upregulated the protein levels of CaSR, protein kinase C (PKC), and inositol trisphosphate receptor (IP3R). However, NPS 2143, an inhibitor of CaSR, attenuated the CCK and GIP release, reduced the mRNA level of CaSR, and decreased the protein levels of CaSR, PKC, and IP3R with 20 mM Trp perfusion. The results indicate that CCK and GIP secretion can be induced by Trp in swine duodenum in vitro, and the effect is mediated by CaSR and its downstream signal molecules PKC and IP3R.

Regulation of gastrointestinal hormones during laxative activity of gallotannin-enriched extract isolated from Galla Rhois in loperamide-induced constipation of SD rats / 한국실험동물학회지

Regulation of gastrointestinal hormones have been reported in animal models for constipation undergoing laxative therapy when administered herbal products. We undertook to investigate whether the laxative activity of gallotannin-enriched extracts isolated from Galla Rhois (GEGR) affects the regulation of gastrointestinal hormones, by examining the concentration of four hormones and the activation of their receptors in the loperamide (Lop)-induced constipation model. Stool parameters, including number, weight and water content, were significantly recovered in the Lop+GEGR treated group, relative to the Lop+vehicle treated group; however, food intake and water consumption were maintained at a constant level. Also, a similar recovery was detected for thickness of mucosa, muscle and flat luminal surface in the Lop+GEGR treated group. Furthermore, concentration of the four gastrointestinal hormones evaluated, namely, cholecystokinin (CCK), gastrin (GAS), somatostatin (SS) and motilin (MTL), were lower in the Lop+vehicle treated group than the No treated group, but were remarkably enhanced in the Lop+GEGR treated group. Moreover, the downstream signaling pathway of MTL and SS receptors were recovered after GEGR administration. Results of the present study therefore indicate that the laxative effects of GEGR treatment may be tightly related with the regulation of gastrointestinal hormones in the Lop-induced constipation model.

Control of Food Intake by Gastrointestinal Peptides: Mechanisms of Action and Possible Modulation in the Treatment of Obesity

This review focuses on the control of appetite by food intake-regulatory peptides secreted from the gastrointestinal tract, namely cholecystokinin, glucagon-like peptide 1, peptide YY, ghrelin, and the recently discovered nesfatin-1 via the gut-brain axis. Additionally, we describe the impact of external factors such as intake of different nutrients or stress on the secretion of gastrointestinal peptides. Finally, we highlight possible conservative—physical activity and pharmacotherapy—treatment strategies for obesity as well as surgical techniques such as deep brain stimulation and bariatric surgery also altering these peptidergic pathways.

Study of the Effect of Cholecystokinin-Induced Acute Pancreatitis on the Free-Running Rhythm of Mouse / 生物医学工程学杂志

The present paper reports the effect of pancreatitis induced by cholecystokinin (CCK) on free-running rhythm of locomotor activity of the ICR mice, and analyzes the interaction of inflammatory diseases and acute pancreatitis with circadian rhythm system. In the study, the mice were modeled under different phases of acute pancreatitis in DD status (Double Dark, constant dark condition). By comparing of the inflammatory status and the indicators of rhythm before and after modeling of the running wheel activity group and the rest group, it was observed that the rest group showed more possibility of inflammation than the activity group did in ICR mice model of acute pancreatitis. In the rest phase model, the extension of the period is particularly longer. The results presented indicated that CCK-induced acute pancreatitis impacted free activity rhythm of ICR mice. Also in a free running model under different phase, the inflammation severity was proved significantly different. This study provides possible clues for the research of the pathogenesis of acute pancreatitis severe tendency.

Effect of the Combination of CI-988 and Morphine on Neuropathic Pain after Spinal Cord Injury in Rats

Cholecystokinin is known to be involved in the modulation of nociception and to reduce the efficacy of morphine analgesia. This study investigated the effects of intrathecal administration of morphine and the cholecystokinin type B antagonist CI-988 on below-level neuropathic pain after spinal cord injury in rats. We also examined the interaction of morphine and CI-988 in the antinociceptive effect. Both morphine and CI-988 given individually increased the paw withdrawal threshold to mechanical stimulation in a dose-dependent manner. The combination of ineffective doses of intrathecally administered CI-988 and morphine produced significant analgesic effects and the combination of effective doses resulted in analgesic effects that were greater than the sum of the individual effects of each drug. Thus, morphine showed a synergistic interaction with CI-988 for analgesia of central neuropathic pain.

Effects of Intraduodenal Infusions of L-phenylalanine and L-glutamine on Antropyloroduodenal Motility and Plasma Cholecystokinin in Healthy Men

BACKGROUND/AIMS: Dietary proteins have potent eating-inhibitory and glucose-lowering effects, which may be mediated via effects of amino acids on gastrointestinal hormone and motor function, although little information is available. We have now evaluated the effects of L-phenylalanine (L-Phe) and L-glutamine (L-Gln) on antropyloroduodenal motility and plasma cholecystokinin (CCK) concentrations. METHODS: Two double-blind, 3-way cross-over studies were performed, each including 10 healthy, normal-weight men. We determined the antropyloroduodenal motor and plasma CCK responses to 90-minute intraduodenal infusions of L-Phe (study A) or L-Gln (study B), each at 0.15 kcal/min (total 13.5 kcal), or 0.45 kcal/min (total 40.5 kcal), or saline (control), in randomized fashion. RESULTS: Intraduodenal L-Phe at 0.45 kcal/min, but not at 0.15 kcal/min, suppressed antral (P < 0.01), and stimulated phasic (P < 0.01), but not tonic, pyloric, or duodenal pressures, while L-Phe at both 0.15 kcal/min and 0.45 kcal/min stimulated plasma CCK. In contrast, L-Gln had no effect on antral, duodenal or pyloric pressures, or plasma CCK. CONCLUSIONS: Intraduodenal infusions of L-Phe and L-Gln, in doses of 0.15 kcal/min and 0.45 kcal/min for 90 minutes, have different effects on antropyloroduodenal motility and CCK in normal-weight men. The modulation of antral and pyloric pressures and CCK may contribute to the eating-inhibitory effects of oral L-Phe, possibly through the slowing of gastric emptying.

The Bitter Taste Receptor Agonist Quinine Reduces Calorie Intake and Increases the Postprandial Release of Cholecystokinin in Healthy Subjects

BACKGROUND/AIMS: Bitter taste receptors are expressed throughout the digestive tract. Data on animals have suggested these receptors are involved in the gut hormone release, but no data are available in humans. Our aim is to assess whether bitter agonists influence food intake and gut hormone release in healthy subjects. METHODS: Twenty healthy volunteers were enrolled in a double-blind cross-over study. On 2 different days, each subject randomly received an acid-resistant capsule containing either placebo or 18 mg of hydrochloride (HCl) quinine. After 60 minutes, all subjects were allowed to eat an ad libitum meal until satiated. Plasma samples were obtained during the experiment in order to evaluate cholecystokinin (CCK) and ghrelin levels. Each subject was screened to determine phenylthiocarbamide (PTC) tasting status. RESULTS: Calorie intake was significantly lower when subjects received HCl quinine than placebo (514 +/- 248 vs 596 +/- 286 kcal; P = 0.007). Significantly higher CCK DeltaT90 vs T0 and DeltaT90 vs T60 were found when subjects received HCl quinine than placebo (0.70 +/- 0.69 vs 0.10 +/- 0.86 ng/mL, P = 0.026; 0.92 +/- 0.75 vs 0.50 +/- 0.55 ng/mL, P = 0.033, respectively). PTC tasters ingested a significantly lower amount of calories when they received HCl quinine compared to placebo (526 +/- 275 vs 659 +/- 320 kcal; P = 0.005), whereas no significant differences were found for PTC non-tasters (499 +/- 227 vs 519 +/- 231 kcal; P = 0.525). CONCLUSIONS: This study showed that intra-duodenal release of a bitter compound is able to significantly affect calorie intake and CCK release after a standardized meal. Our results suggest that bitter taste receptor signaling may have a crucial role in the control of food intake.

The Resveratrol-induced Relaxation of Cholecystokinin Octapeptide- or KCl-induced Tension in Male Guinea Pig Gallbladder Strips Is Mediated Through L-type Ca2+ Channels

BACKGROUND/AIMS: Resveratrol (3,5,4'-trihydroxystilbene) is a polyphenolic compound (stilbene) and a phytoalexin. The purpose of this study was to determine the mechanism which mediated the resveratrol-induced relaxation of cholecystokinin octapeptide- or KCl-induced tension in male guinea pig gallbladder strips. METHODS: Gallbladder strips were prepared and suspended in in vitro chambers filled with Krebs-Henseleit solution. The strips were attached to force displacement transducers, and the changes in tension were recorded on a polygraph. All reagents were added directly into the chambers. RESULTS: To determine if intracellular Ca2+ release mediated the resveratrol-induced relaxation of cholecystokinin octapeptide-induced tension, 2-aminoethoxydiphenylborane (2-APB) was used. 2-APB significantly (P < 0.01) decreased the amount of RSVL-induced relaxation. To determine if protein kinase A (PKA) mediated the resveratrol-induced relaxation, PKA inhibitor 14-22 amide myristolated (PKA-IM) was used. PKA-IM had no effect on resveratrol-induced relaxation. Neither KT5823, N(G)-methyl-L-arginine acetate salt, a nitric oxide synthase inhibitor, nor fulvestrant had a significant effect on the amount of resveratrol-induced relaxation. Genistein, a protein tyrosine kinase inhibitor, significantly (P < 0.01) increased the RSVL-induced relaxation. To determine if protein kinase C mediated the RSVL-induced relaxation, the protein kinase C inhibitors bisindolymaleimide IV and chelerythrine Cl- were used together, and a significant (P < 0.05) increase in resveratrol-induced relaxation was observed. The pretreatment of the strips with resveratrol significantly (P < 0.001) decreased the amount of KCl- and cholecystokinin octapep-tide-induced tension. CONCLUSIONS: Resveratrol-induced relaxation is mediated by its effects on L-type Ca2+ channels and intracellular Ca2+ release.

Naringenin stimulates cholecystokinin secretion in STC-1 cells

BACKGROUND/OBJECTIVES: Cholecystokinin (CCK), a hormone or neuropeptide, is secreted in response to intraluminal nutrients by enteroendocrine I-cells of the intestine and has important physiological actions related to appetite regulation and satiety. The stimulation on CCK secretion from the intestine is of potential relevance for body weight management. Naringenin (4',5,7-trihydroxyflavanone) and its glycoside naringin (naringenin 7-rhamnoglucoside) have been reported to have many biological functions. In the current study, we investigated the question of whether naringenin and naringin could stimulate CCK secretion and then examined the mechanisms involved in CCK release. MATERIALS/METHODS: STC-1 cells were used as a model of enteroendocrine cells. CCK release and changes in intracellular Ca2+ ([Ca2+]i) were measured after incubation of cells with naringenin and naringin for 1 h. RESULTS: Naringenin caused significant (P < 0.05) stimulation of CCK secretion, but naringin did not. In addition, regarding the secretory mechanisms, naringenin-induced CCK secretion involved increases in [Ca2+]i, influx of extracellular Ca2+, at least in part, and activation of TRP channels, including TRPA1. CONCLUSION: Findings of this study suggest that naringenin could have a role in appetite regulation and satiety.

Cholecystokinin modulation of maternal behavior

Maternal behavior is regulated by several neurotransmitters, neuropeptides, and hormones. This mini-review focuses on the role of cholecystokinin (CCK), a neuropeptide and gut hormone best known as a satiety signal, in mediating maternal behavior. In addition to the role of CCK in the infant in mother-infant interactions, maternal CCK appears to also be important. We discuss maternal behavior research, mainly in rats, that has examined the effect of administering CCK to dams, CCK-opioid interactions, and maternal behavior in rats that lack CCK1 receptors. We discuss the possibility that CCK might play a role in neurological adjustments during pregnancy that ultimately influence behavioral adaptations by the offspring during lactation. Finally, we hypothesize that maternal CCK is also involved in maternal memory and reward...

Age-associated changes in pancreatic exocrine secretion of the isolated perfused rat pancreas / 한국실험동물학회지

Gut functions, such as gastrointestinal motility, gastric secretion and pancreatic secretion, were reduced with age. Glucose tolerance is impaired, and the release of insulin and beta-cell's sensitivity on glucose are reduced with age. However, a lot of controversial data have been reported as insulin concentrations after glucose ingestion are either higher or no different in elderly and young subjects. Thus, this study was aimed to investigate whether aging could affect pancreatic exocrine secretion and its action mechanisms. An isolated perfused rat pancreatic model was used to exclude the effects of external nerves or hormones. Pancreatic secretion was increased by CCK under 5.6 mM glucose background in the isolated perfused pancreas of young (3 months), 12 months and 18 months aged rats. There was no significant difference between young and aged rats. In 3 months old rats, CCK-stimulated pancreatic secretion was potentiated under 18 mM glucose background. However, the potentiation effects of endogenous insulin and CCK were not observed in 12 and 18 months old rats. Exogenous insulin also potentiated CCK-stimulated pancreatic secretion in 3 months old rats. Similarly, exogenous insulin failed to potentiate CCK-stimulated pancreatic secretion as that of 3 months old rats. Wet weight of pancreas and amylase content in pancreatic tissue were not changed with age. These results indicate that pancreatic exocrine secretion is reduced with age and endogenous insulin secretion and/or action is involved in this phenomenon.

Effects of the Addition of Mosapride to Gastroesophageal Reflux Disease Patients on Proton Pump Inhibitor: A Prospective Randomized, Double-blind Study

BACKGROUND/AIMS: Proton pump inhibitors (PPIs) which are the most effective agents for the treatment of gastroesophageal reflux disease (GERD), have been known to delay gastric emptying. Mosapride has been used as prokinetics by accelerating gastric emptying. We evaluated the efficacy of mosapride to prevent PPI-induced delayed gastric emptying in a prospective randomized, double-blind and placebo-controlled trial. METHODS: Thirty patients who were diagnosed as GERD and had normal gastric emptying were included in this study. PPI monotherapy group was treated with placebo drug in addition to pantoprazole and PPI plus mosapride group was treated with mosapride in addition to pantoprazole for 8 weeks. Gastric emptying scan and questionnaires about GERD and dyspeptic symptoms were assessed by scoring before and after treatment. To evaluate the changes of gastrointestinal endocrine hormones by PPI which are associated gastric acid secretion and gastric motility, fasting plasma gastrin and cholecystokinin were taken at weeks 0 and 8. RESULTS: Half gastric emptying time was increased (P = 0.023) in PPI monotherapy group, and there were no significant changes in PPI plus mosapride group. Plasma gastrin level increased in PPI monotherpay group (P = 0.028) and there were no significant changes in PPI plus mosapride group. Plasma cholecystokinin level was not changed after treatment in both groups. GERD symptoms were improved after treatment in both groups, and postprandial bloating and nausea were improved in PPI plus mosapride group. CONCLUSIONS: Mosapride showed to be effective in preventing delayed gastric emptying and the increase in plasma gastrin level induced by PPI treatment, but did not show prominent clinical symptom improvements.

Hesperetin Stimulates Cholecystokinin Secretion in Enteroendocrine STC-1 Cells

Hesperetin (3',5,7-trihydroxy 4'-methoxyflavanone) and its glycoside hesperidin (hesperetin 7-rhamnoglucoside) in oranges have been reported to possess pharmacological effects related to anti-obesity. However, hesperetin and hesperidin have not been studied on suppressive effects on appetite. This study examined that hesperetin and hesperidin can stimulate the release of cholecystokinin (CCK), one of appetite-regulating hormones, from the enteroendocrine STC-1 cells, and then examined the mechanisms involved in the CCK release. Hesperetin significantly and dose-dependently stimulated CCK secretion with an EC50 of 0.050 mM and increased the intracellular Ca2+ concentrations ([Ca2+]i) compared to the untreated control. The stimulatory effect by hesperetin was mediated via the entry of extracellular Ca2+ and the activation of TRP channels including TRPA1. These results suggest that hesperetin can be a candidate biomolecule for the suppression of appetite and eventually for the therapeutics of obesity.

Role of Janus Kinase/Signal Transducers and Activators of Transcription in the Pathogenesis of Pancreatitis and Pancreatic Cancer

In the pathogenesis of pancreatitis, oxidative stress is involved in the activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway and cytokine expression. High serum levels of cholecystokinin (CCK) have been reported in patients with acute pancreatitis, and treatment with cerulein, a CCK analogue, induces acute pancreatitis in a rodent model. Recent studies have shown that cerulein-activated nicotinamide adenine dinucleotide phosphate oxidase elicits reactive oxygen species, which trigger the phosphorylation of the JAK1, STAT1, and STAT3 proteins and induce the production of inflammatory cytokines, such as tumor necrosis factor-alpha, interleukin (IL)-1beta, and IL-6, in pancreatic acinar cells. The JAK/STAT pathway also stimulates cell proliferation and malignant transformation and inhibits apoptosis in the pancreas. This review discusses the possible role of the JAK/STAT pathway in the pathogenesis of pancreatitis and pancreatic cancer in response to oxidative stress.

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.