Antral Cells Research Articles

The differential transcriptome and ontology profiles of floating and cumulus granulosa cells in stimulated human antral follicles

Communication between various ovarian cell types is a prerequisite for folliculogenesis and ovulation. In antral follicles granulosa cells divide into two distinct populations of mural and cumulus granulosa cells (CGC), enveloping the antrum and surrounding the oocyte, respectively. Both cell types, with the mural compartment in excess, contribute to the floating granulosa cell (FGC) population in the follicular fluid. The aim of this study was to compare the transcriptomes of FGC and CGC in stimulated antral follicles obtained from 19 women undergoing IVF-ICSI procedure. FGC were obtained from follicular fluid during the follicle puncture procedure and CGC were acquired after oocyte denudation for micromanipulation. Gene expression analysis was conducted using the genome-wide Affymetrix transcriptome array. The expression profile of the two granulosa cell populations varied significantly. Out of 28 869 analysed transcripts 4480 were differentially expressed (q-value < 10(-4)) and 489 showed > or =2-fold difference in the expression level with 222 genes up-regulated in FGC and 267 in CGC. The transcriptome of FGC showed higher expression of genes involved in immune response, hematological system function and organismal injury, although CGC had genes involved in protein degradation and nervous system function up-regulated. Cell-to-cell signalling and interaction pathways were noted in both cell populations. Furthermore, numerous novel transcripts that have not been previously described in follicular physiology were identified. In conclusion, our results provide a solid basis for future studies in follicular biology that will help to identify molecular markers for oocyte and embryo viability in IVF.

Declines in Levels of Hyperpolarization-Activated Cation (HCN) Channels in the Rat Ovary After Cisplatin Exposure

The distribution of the 4 hyperpolarization-activated cation (hyperpolarization-activated, cyclic nucleotide-gated [HCN]) channels (HCN1-4), channels associated with rhythmic electrical bursting, varies in the different cells of the ovary. Cisplatin is a broadly used chemotherapeutic agent that results in ovarian damage. The objective of this study was to test the hypothesis that cisplatin treatment will affect expression of the ovarian HCN channels. Adult female Sprague-Dawley rats were dosed with saline, 4.5 mg/kg cisplatin, or 6.0 mg/kg cisplatin as 2 weekly injections and then were killed 5 days after the second cisplatin dose. The ovaries were studied for HCN1-4 using semiquantitative H score immunohistochemical analysis and using Western blot analysis. By immunohistochemistry, for HCN4, the oocyte-specific staining declined after cisplatin treatment (P < .001). There was a decline in HCN2 intensity after cisplatin in the antral granulosa cells (P < .05) and thecal cells (P < .05). There were no differences found for the immunohistochemical HCN1 and HCN3 H scores after cisplatin. The Western blot analysis revealed that there was a decline in HCN3 levels after cisplatin exposure (P < .05). For HCN1 and HCN2, there was no change in the total ovarian protein levels after cisplatin. Treatment in vivo with cisplatin resulted in decline in the levels of the HCN channels in the rat ovary, with oocytes, antral cells, and thecal cells being specifically affected.

Morphology and steroidogenesis of cultured granulosa cells from endometrioidally changed ovaries.

The aim of the study was to see the function of follicular cells collected from ovaries of women suffering from endometriosis. The material was granulosa cells taken from 11 patients operated on 3rd and 4th degree of endometriosis. Antral granulosa cells were harvested from 34 medium-size (5-10 mm in diameter) follicles located on the cysts' walls or in the cysts' vicinity. Using the culture method, morphology and steroid secretion was estimated. Morphological properties of the cells in the culture did not differ significantly from that of healthy ones. All cells formed a monolayer and achieved different degrees of luteinization. Steroidogenesis of these granulosa cells was defected, particularly in the production of progesterone and testosterone.

Studies of granulosa cell maturation in dominant and subordinate bovine follicles: novel extracellular matrix focimatrix is co-ordinately regulated with cholesterol side-chain cleavage CYP11A1

During growth of antral ovarian follicles granulosa cells first become associated with a novel type of extracellular matrix, focimatrix, and at larger sizes follicles become either subordinate or dominant. To examine this, bovine subordinate (9.0+/-S.E.M. 0.4 mm; n=16), partially dominant (12.0+/-0.6 mm; n=18) and fully dominant (15.0+/-0.4 mm; n=14) follicles were examined by real time RT-PCR analyses of granulosa cells and by immunohistochemistry of focimatrix. Changes in the expression of FSH receptor, LH receptor, cholesterol side-chain cleavage (CYP11A1), 3beta-hydroxysteroid dehydrogenase, aromatase (CYP19A1) and inhibin-alpha and beta-B were observed as expected for follicle sizes examined. After adjusting for size differences, only CYP11A1 was significantly different between the groups, and elevated in dominant follicles. Also after adjusting for differences in size there were no significant differences in expression of focimatrix components collagen type IV alpha-1 (COL4A1), laminin beta-2, nidogen 1 (NID1), and perlecan (HSPG2) or the volume density of NID1 and -2 and HSPG2. The volume density of focimatrix components in laminin 111 was significantly elevated in dominant follicles. Adjusting for analysis of more than one follicle per animal and for multiple correlations, CYP11A1 mRNA levels were highly correlated with the focimatrix genes COL4A1, NID1 and -2 and HSPG2. Thus, focimatrix may potentially regulate CYP11A1 expression, and the regulation of both could be important in follicular dominance.

Developmental programming: prenatal androgen excess disrupts ovarian steroid receptor balance

Steroid hormones play an important role in reproduction and the receptors through which they signal change in a developmental time, follicle stage, and cell-specific manner. Disruption in steroid receptor expression affects follicle formation and differentiation. In this study, using prenatal testosterone (T) and dihydrotestosterone (DHT)-treated female sheep as model systems, we tested the hypothesis that prenatal androgen excess disrupts the developmental ontogeny of ovarian steroid receptor protein expression. Pregnant Suffolk ewes were injected twice weekly with T propionate or DHT propionate (a non-aromatizable androgen) in cottonseed oil from days 30 to 90 of gestation. Changes in ovarian estrogen receptors (ER; ESR1, ESR2), androgen receptor (AR) and progesterone receptor (PGR) proteins were determined at fetal (days 90 and 140), postpubertal (10 months), and adult (21 months; only prenatal T-treated sheep studied) ages by immunohistochemistry. Prenatal T and DHT treatment induced selective increase in AR but not ER or PGR expression in the stroma and granulosa cells of fetal days 90 and 140 ovaries. An increase in ESR1 and decrease in ESR2 immunostaining coupled with increased AR expression were evident in granulosa cells of antral follicles of 10- and 21-month-old prenatal T but not DHT-treated females (analyzed only at 10 months). These findings provide evidence that an early increase in ovarian AR is the first step in the altered ovarian developmental trajectory of prenatal T-treated females, and manifestations of postnatal ovarian dysfunction are likely facilitated via altered equilibrium of antral follicular granulosa cell ER/AR protein expression.

Effects of Dendroaspis natriuretic peptide on delayed rectifier potassium currents and its mechanism

Dendroaspis natriuretic peptide (DNP), a newly-described natriuretic peptide, plays an inhibitory role in smooth muscle motility of the gastrointestinal tract. However, the effect of DNP on delayed rectifier potassium currents I K(V) is still unclear. In this study, we sought to investigate the effect of DNP on I K(V) and its mechanism in gastric antral circular smooth muscle cells using the whole-cell patch-clamp technique. DNP significantly inhibited I K(V) in a concentration-dependent manner. LY83583 (1 µmol/l), a guanylate cyclase inhibitor, significantly impaired DNP-induced inhibition of I K(V). Moreover, DNP-induced inhibition in I K(V) was potentiated by the cyclic guanosine monophosphate (cGMP) sensitive phosphoesterase inhibitor zaparinast (0.1 µmol/l). DNP-induced inhibition of I K(V) was completely blocked by KT5823, an inhibitor of cGMP-dependent protein kinase G(PKG), but not affected by KT-5720, a PKA-specific inhibitor. Taken together, our results suggest that DNP inhibits I K(V) via the cGMP/PKG-dependent signaling axis instead of the cAMP/PKA pathway.

Effects of Xuanfu Daizhe Decoction on cell contraction and intracellular calcium concentration in rat gastric antral smooth muscle cells

Effects of Xuanfu Daizhe Decoction on cell contraction and intracellular calcium concentration in rat gastric antral smooth muscle cells

Amplification and invasiveness of epithelial progenitors during gastric carcinogenesis in trefoil factor 1 knockout mice.

It is not known whether or not epithelial progenitors of the pyloric antrum are involved in gastric carcinogenesis. Normally, these progenitors give rise to two main cell lineages: pit and gland mucous cells. This study was designed to examine the changes that occur in pyloric antral mucous cell lineages and their progenitors during development of gastric adenoma and carcinoma in trefoil factor 1 (TFF1) knockout mice. Pyloric antral mucosal tissues of TFF1 knockout mice at ages from 3 days to 17 months were processed for histochemical analysis using Ulex europaeus and Grifforia simplifolica lectins as markers for pit and gland mucous cells, respectively. The dividing epithelial progenitors were identified by using immunohistochemical and electron microscopy techniques. TFF1 loss was associated with amplification of both mucus-secreting pit and gland cells. Both lectins examined bound not only to mature mucous cells, but also to most of epithelial progenitors which gradually amplified with age and frequently were seen in mitosis. Analysis of 12- to 17-month-old TFF1-deficient stomachs revealed occasional groups of poorly differentiated mucosal cells with features similar to those of epithelial progenitors (or stem cells), in the basal portion of the antral mucosa. These cells eventually invaded the muscularis mucosa while maintaining some capacity to differentiate. This study shows that the progenitors of pit and gland mucous cells contribute to gastric carcinogenesis in the pyloric antrum of TFF1 knockout mice, strongly supporting the concept of stem cell origin of cancer.

Regulated expression of the human gastrin gene in mice

Gastrin is secreted from neuroendocrine cells residing in the adult antrum called G cells, but constitutively low levels are also expressed in the duodenum and fetal pancreas. Gastrin normally regulates gastric acid secretion by stimulating the proliferation of enterochromaffin-like cells and the release of histamine. Gastrin and progastrin forms are expressed in a number of pathological conditions and malignancies. However, the DNA regulatory elements in the human versus the mouse gastrin promoters differ suggesting differences in their transcriptional control. Thus, we describe here the expression of the human gastrin gene using a bacterial artificial chromosome (BAC) in the antral and duodenal cells of gastrin null mice. All 5 founder lines expressed the 253 kb human gastrin BAC. hGasBAC transgenic mice were bred onto a gastrin null background so that the levels of human gastrin peptide could be analyzed by immunohistochemistry and radioimmunoassay without detecting endogenous mouse gastrin. We have shown previously that chronically elevated gastrin levels suppress somatostatin. Indeed, infusion of amidated rat gastrin depressed somatostatin levels, stimulated gastric acid secretion and an increase in the numbers of G cells in the antrum and duodenum. In conclusion, human gastrin was expressed in mouse enteroendocrine cells and was regulated by somatostatin. This mouse model provides a unique opportunity to study regulation of the human gastrin promoter in vivo by somatostatin and possibly other extracellular regulators contributing to our understanding of the mechanisms involved in transcriptional control of the human gene.

Antral Inflammatory Cells, Gastric Emptying, and Electrogastrography in Pediatric Functional Dyspepsia

The aims of the current study were to determine the activation states of antral eosinophils and mast cells and to evaluate the interactions of antral inflammatory cells with gastric emptying and electrogastrography (EGG) in 30 pediatric patients with functional dyspepsia. Eosinophil degranulation was moderate in 42% and extensive in 54% of patients. Mast cell degranulation was > 50% in 81% of patients. Elevated mast cell density was associated with slower one hour gastric emptying and increased preprandial dysrhythmia. Mast cell density correlated with the preprandial percentage tachygastria. CD3+ cell density correlated with the preprandial percentage tachygastria also, but only in patients with increased eosinophil density. In conclusion, antral eosinophils and mast cells are significantly activated in pediatric functional dyspepsia. Mast cell density is associated with delayed gastric emptying and preprandial dysrhythmia, suggesting that there may be an interaction between antral inflammation and gastric electromechanical dysfunction in the pathophysiology of pediatric functional dyspepsia.

Nitric oxide regulates steroid synthesis by bovine antral granulosa cells in a chemically defined medium

Nitric oxide (NO) in bovine ovary has been characterized as one of the controllers of granulosa cells’ (GC) steroidogenesis and apoptosis. One of the pathways used by NO to have these effects is cGMP. The objectives of the present study were to verify the effect of sodium nitroprusside (SNP), a NO donor, on steroidogenesis, cell viability (mitochondrial activity) and GC cell cycle distribution and if this effect occurs by the NO-cGMP signaling pathway with the addition of SNP with or without 1H-[1,2,3] oxadiaziolo[4,3a]quinoxaline-1-one (ODQ), a selective soluble guanylate cyclase inhibitor. The antral GC from 3 to 5 mm diameter cattle follicles was cultured without treatment (control), with ODQ (10 −4 M) and 10 −5, 10 −3 and 10 −1 M SNP with or without ODQ for 24 h. Nitrate/nitrite (NO 3 −/N0 2 −) concentrations were evaluated by Griess method, progesterone (P 4) and 17β-estradiol (E 2) concentrations by chemiluminescence, viability and cell cycle stage by MTT method (3-[4,5-dimethylthiazol-2yl]-2,3 dipheniltetrazolium bromide) and flow cytometry, respectively. Nitrate/nitrite concentration in culture medium increased ( P < 0.05) in a dose-dependent manner according to SNP concentration added to the culture medium. The GC cultured without treatment, with ODQ and with 10 −5 M SNP in the presence or absence of ODQ developed into cell aggregates and did not vary in cell viability ( P > 0.05), while GC cultured with 10 −3 and 10 −1 M SNP with or without ODQ presented disorganized GC aggregates or did not develop into cell aggregates and also had substantially decreased cell viability (mitochondrial activity inhibition) and steroids synthesis ( P < 0.05), and effects were not reversed with us of ODQ. Most GC cultured without treatment (control) or with ODQ, 10 −5 and 10 −3 M SNP with or without ODQ were in the G0/G1 (80–75%) stage and in a lesser proportion (20–25%) in the S + G2/M stage of the cell cycle, while the 10 −1 M SNP treatment resulted in GC in G1 phase arrest. The treatment with 10 −5 M SNP increased ( P < 0.05) E 2 synthesis and inhibited ( P < 0.05) progesterone synthesis. The addition of ODQ reversed ( P < 0.05) the stimulatory effect of 10 −5 M SNP treatment on E 2, but not on P 4 synthesis ( P > 0.05). These results demonstrated that E 2 synthesis by antral GC from small follicles is modulated by lesser NO concentrations via the cGMP pathway, but not P 4 while steroids inhibition cGMP pathway independent, mitochondrial damage and the interference on cell cycle progression caused by greater NO concentration can lead to cell death.

PKD1, PKD2, and Their Substrate Kidins220 Regulate Neurotensin Secretion in the BON Human Endocrine Cell Line

Neurotensin (NT) is a gut peptide that plays an important role in gastrointestinal secretion, motility, and growth as well as the proliferation of NT receptor-positive cancers. Protein kinase D (PKD) family members (PKD1, 2, and 3) have been identified as important regulators of secretory transport at the trans-Golgi network. Previously, we showed that PKD1 contributes to stimulated NT secretion; however, the mechanisms are not entirely clear. Here, we show that Kidins220, which is a substrate of PKD proteins in neuroendocrine cells, is localized in the ends of the processes of BON cells, similar to the expression pattern of NT vesicles, and translocates to the membrane and large vesicle-like structures formed in response to phorbol 12-myristate 13-acetate treatment. The short hairpin RNA targeting Kidins220 inhibits NT secretion in parental BON cells or BON cells stably expressing the gastrin-releasing peptide receptor treated with either phorbol 12-myristate 13-acetate or bombesin, respectively. Furthermore, we demonstrate that endogenous PKD1, PKD2, and Kidins220 co-exist with NT-containing vesicles. Overexpression of the kinase-dead PKD1 abrogates Kidins220 expression and NT vesicle formation. Our data establish a physiological link between the PKD/Kidins220 pathway and NT-containing vesicles and suggest the role of this pathway in the regulation of hormone secretion. Because NT is an important gut hormone that affects secretion, inflammation, and both normal and tumor cell growth, our findings identify a novel signaling pathway that may be amenable to drug targeting for clinical applications.

Effects of Dendroaspis Natriuretic Peptide on Calcium-Activated Potassium Current and Its Mechanism

In this study, we sought to investigate the effect of dendroaspis natriuretic peptide (DNP) on calcium-activated potassium current (I K(Ca)) and its mechanism in gastric antral circular smooth muscle cells (SMCs) using the whole-cell patch-clamp technique. DNP concentration-dependently increased macroscopic I K(Ca) and spontaneous transient outward currents (STOCs) in freshly isolated guinea pig gastric antral circular SMCs. The effects of DNP on I K(Ca) and/or STOCs were not blocked by applying calcium-free bath solution or the ryanodine receptor (RyR) antagonist ryanodine (10 microM), but they were inhibited by the inositol triphosphate receptor (IP3R) inhibitor heparin or the guanylate cyclase inhibitor LY83583. Moreover, a DNP-induced increase in STOCs was potentiated by the cyclic guanosine monophosphate (cGMP)-sensitive phosphoesterase inhibitor zaprinast. In conclusion, our results suggest that DNP increases I K(Ca) in gastric antral circular SMCs by increasing cGMP production and activating IP3Rs.

The role of protein kinase C-mediated phosphorylation of type III inositol 1, 4, 5-triphosphate receptor in cholecystokinin octapeptide induced calcium mobilization in gastric antral smooth muscle cells

To study the effects of sulfated cholecystokinin octapeptide (sCCK-8S) on intracellular calcium release and extracellular calcium influx in gastric antral smooth muscle cells (SMC) and the mechanism thereof. (1) Longitudinal muscle (LM) and circular muscle (CM) strips of gastric antrum and pylorus were isolated from SD rats and suspended in a tissue chamber to record the contractile responses by polyphysiography. (2) Immunoprecipitation, electrophoresis, and immunoblotting were used to detect the phosphorylation of type III inositol 1, 4, 5-triphosphate receptor (InsP(3)R(3)) in the SMCs. (3) The responsiveness of gastric SMC to CCK-8S was examined by using fura-2-loaded microfluorimetric measurement of intracellular calcium concentration ([Ca(2+)]i). (4) The current of L-type calcium channels (ICaL) was recorded by using patch-clamp techniques. (1) Significant changes to CCK-8S were found in the mean contractile amplitude of the CM and frequency of LM of gastric antrum and could be suppressed by CCK-A receptor (CCK-AR) antagonist and ATPase inhibitors. (2) CCK-8S stimulation of SMC resulted in PKC-dependent phosphorylation of the InsP(3)R(3). (3) CCK-8S-evoked significant increase in [Ca(2+)]i [from (69 +/- 7) mol/L to (472 +/- 36) nmol/L, P < 0.01] could be suppressed by CCK-AR antagonist, ATPase inhibitors and protein kinase C (PKC) activator; whereas on condition that extracellular calcium was removed or L-type calcium inhibitor nifedipine was added a small but significant increase of [Ca(2+)]i could be still elicited by CCK-8S. (4) CCK-8S-intensified calcium current [from (-56 +/- 7) pA to (-89 +/- 6) pA, P < 0.01] could be apparently inhibited by respective administration of nifedipine, ATPase inhibitors, and calcium dependent chloride channel (I(Cl-Ca)) blocker (all P < 0.01). CCK-8S-evoked [Ca(2+)]i increase in gastric antral SMCs depends on the release of intracellular calcium stores, which is regulated by PKC mediated phosphorylation of InsP(3)R(3). The released intracellular calcium in turn activates the L-type voltage-dependent calcium channels (VDCC) through the activation of calcium dependent chloride channels, and ultimately results in the occurrence of contraction response of smooth muscles.

Immunohistochemical Localization of Androgen Receptor in Two Subpopulations of Porcine Granulosa Cells In Vitro

In the ovarian follicles of mammals, androgens are utilized as substrates for estrogen synthesis or can act via androgen receptor (AR). Within the ovary, granulosa cells generally display the strongest immunoreactivity for AR protein. Therefore, the aim of the present study was to analyse possible changes in the intensity of AR staining in cultured mural and antral granulosa cells isolated from follicles at various stages of development. Porcine ovaries were obtained at a local slaughterhouse and the follicles were classified as small, medium and large dependently on their diameter. Isolated granulosa cells were separated into two populations, mural and antral, and then the cells were cultured during 48 h. After this time the cells were fixed and immunostained to visualize the AR. Androgen receptor immunostaining was detected in both, antral and mural granulosa cell cultures isolated from follicles at all stages of the development. In the mural granulosa cultures the immunostaining was comparatively weaker than that in the antral granulosa cells originating from all types of follicles. Our results provide immunohistochemical evidence that antral granulosa layer is the main site of AR immunoexpression.

Expression of NF-κB in Helicobacter pylori Infection

Helicobacter pylori colonizes the gastric mucosa in humans and causes chronic gastritis. NF-kappaB has a key role as a mediator in mucosal inflammation. In this study, we examined the expression of NF-kappaB in the antral epithelial cells of H. pylori-infected and H. pylori-uninfected biopsies and examined these processes in relationship with grade and activity of gastritis, density of H. pylori, presence of the intestinal metaplasia, and atrophy. Fifty biopsies (35 H. pylori-positive patients and 15 H. pylori-negative controls) were studied. NF-kappaB immunohistochemical stain was performed. NF-kappaB activity in H. pylori-infected biopsies were markedly enhanced compared with uninflamed biopsies (P = 0.001). We also found positive correlation NF-kappaB expression with severity of gastritis (according to Sydney score) (P = 0.001), activity of gastritis (P = 0.046) and H. pylori load (P < 0.001), and atrophy (P = 0.004). We did not find a significant relationship between NF-kappaB and the presence of intestinal metaplasia (P = 0.355). These findings suggested that expression of NF-kappaB has an important role in H. pylori gastritis.

Prostaglandin E2 release in gastric antral mucosa of guinea‐pigs: basal PGE2 release by cyclo‐oxygenase 2 and ACh‐stimulated PGE2 release by cyclo‐oxygenase 1

Prostaglandin E(2) (PGE(2)), which is generated by two isoforms of cyclo-oxygenase (COX(1) and COX(2)), is a key mediator in gastric mucosal defense. In the present study, antral mucosa of guinea-pigs was incubated with various agonists or antagonists in a medium, the PGE(2) concentration of which was measured using a PGE(2) EIA kit. Prostaglandin E(2) was released from the antral mucosa spontaneously (basal PGE(2) release) and acetylcholine (ACh, 10 microM) enhanced the PGE(2) release (ACh-stimulated PGE(2) release) was mediated via intracellular Ca(2+) concentration ([Ca(2+)](i)). Arachidonic acid enhanced both forms of PGE(2) release, and a phospholipase A(2) inhibitor (amylcinnamoyl anthranilic acid) and COX inhibitors (acetylsalicylic acid and indomethacin) decreased them. 5-(4-Chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazol (SC560, 100 nm, a COX(1)-selective inhibitor) inhibited ACh-stimulated PGE(2) release without any decrease in basal PGE(2) release. N-(2-Cyclohexyloxy-4-nitrophenyl) methanesulphonamide (NS398, 20 microM, a COX(2)-selective inhibitor) decreased basal PGE(2) release without any reduction of ACh-stimulated PGE(2) release. However, ionomycin (a Ca(2+) ionophore) increased PGE(2) release from antral mucosa in the presence of SC560 or NS398, suggesting that COX(1) and COX(2) are regulated by [Ca(2+)](i). These findings indicate that COX(1)-containing cells have ACh receptors but COX(2)-containing cells do not. Moreover, in isolated antral epithelial cells, SC560 decreased basal and ACh-stimulated PGE(2) release, but NS398 did not. In conclusion, in antral mucosa, basal PGE(2) release is mainly maintained by COX(2) of non-epithelial cells, and ACh-stimulated PGE(2) release is maintained by COX(1) of epithelial cells.

THE RELATIONSHIP BETWEEN DYSPEPSIA SUBTYPE AND MUCOSAL INFLAMMATION

Purpose: The current study was undertaken to determine if dyspepsia subtype or individual dyspeptic symptoms are predictive of the presence of mucosal inflammation. Methods: Sixty-five patients (ages 8-17, mean 12.3 years; 50 F) undergoing endoscopy for evaluation of dyspepsia were enrolled. By Rome II criteria, there were 48 patients with ulcer-like dyspepsia (ULD) and 17 with dysmotility-like dyspepsia (DLD). Additionally, the presence of specific symptoms including epigastric pain, post-prandial pain, early satiety, nausea, bloating, and fullness was determined by patient report. All patients had biopsies obtained from each of the esophagus, antrum, and duodenum. The presence of histologic esophagitis, gastritis, and duodenitis, respectively, were determined in a standard fashion. Additionally, mucosal cell densities were determined for eosinophils and mast cells, respectively, for both the antrum and duodenum. Results: ULD was not associated with an increase in esophagitis, gastritis, or duodenitis, respectively, as compared to DLD. ULD was associated with an increase in both mean (24.1 + 12.9 vs. 18.3 + 8.1, P = 0.04) and peak (35.4 + 19.8 vs. 27.3 + 8.9, P = 0.03) duodenal eosinophil counts as compared to DLD. With regard to individual symptoms, epigastric pain was associated with a lower prevalence of both gastritis (20% vs. 52%, P =.015) and duodenitis (16% vs. 48%, P = 0.013) and lower mean antral mast cells (12.8 + 4.1 vs. 15.3 + 4.8, P = 0.048). Post-prandial pain was associated with an increased prevalence of gastritis (48% vs. 9%, P = 0.03) but no difference in eosinophil or mast cell density. There were no other significant associations. Conclusions: Other than a mild increase in duodenal eosinophils, ULD is not associated with an increase in mucosal inflammation as compared to DLD. Post-prandial pain is associated with an increased prevalence of gastritis while epigastric pain appears to be a negative predictor of mucosal inflammation.

Signal Transduction Pathways Mediating CCK-8S-Induced Gastric Antral Smooth Muscle Contraction

Aim: To investigate the functional and molecular mechanisms by which sulfated cholecystokinin octapeptide (CCK-8S) regulates calcium mobilization in gastric antral smooth muscle cells (SMCs) of rats. Methods: Isotonic contraction of antral strips was recorded using a polyphysiograph. Immunoprecipitation was used to determine the regulatory effect of protein kinase C (PKC) on regulating the phosphorylation of the type III inositol 1,4,5-triphosphate receptor (InsP₃R3) in gastric SMCs. Alterations in the intracellular calcium ([Ca²⁺]_i) concentration were assayed using fura-2/AM-loaded microspectrofluorometry, and the L-type calcium current (I_Ca-L) was recorded by patch-clamp techniques. Results: CCK-8S (5 × 10^–8 mol/l) significantly increased the mean contractile amplitude of circular muscle by 61.85 ± 12.67% and the frequency of longitudinal muscle by 57.91 ± 15.70% in gastric antral strips, which were suppressed by dexloxiglumide or thapsigargin (TG) and BAPTA-AM (BA). Treatment withchelerythrine (5 × 10^–8 mmol/l) significantly inhibited the CCK-8S-increased phosphorylation of InsP₃R3 in SMCs. The amplitudes of the CCK-8S-triggered [Ca²⁺]_i concentration oscillations were reduced in a dose-dependent manner when the SMCs were pretreated with increasing concentrations of PMA (from 10^–8 to 10^–5 mol/l). On removal of extracellular calcium or blocking I_Ca-L by nifedipine, a smaller but significant rise in the [Ca²⁺]_i concentration was still elicited by CCK-8S. When [Ca²⁺]_i was depleted by the administration of 10^–5 mol/l TG and 10^–5 mol/l BA or blocked by the calcium-dependent chloride current (I_Cl-Ca) by giving 5 × 10^–6 mol/l niflumic acid, the CCK-8S-intensified I_Ca-L (from –56.42 ± 6.57 to –88.54 ± 5.71 pA) was apparently inhibited by 90.34 ± 4.71% and 82.59 ± 4.24%. Conclusions: These results demonstrate that the CCK-8S-evoked [Ca²⁺]_i concentration increase in gastric antral SMCs depends on the release of [Ca²⁺]_i stores which are negatively regulated by PKC-mediated phosphorylation of InsP₃R3. Released calcium in turn activates I_Ca-L through the activation of I_Cl-Ca, ultimately resulting in the contraction of the gastric smooth muscle.

Serotonin-producing enterochromaffin (EC) cells of gastrointestinal mucosa in dexamethasone-treated rats

The aim of our study was to investigate the morphological, immunohistochemical and ultrastructural changes of rat serotonin-producing enterochromaffin (EC) cells of gastrointestinal mucosa in dexamethasone-treated rats (D). After 12-daily intraperitoneal administration of 2 mg/kg dexamethasone, rats developed diabetes similar to human diabetes type 2. Stomach, small and large intestines were examined. Large serotonin positive EC cells appeared in the corpus mucosa epithelium of D group of rats, although these cells were not present in control (C) rats. Both volume fraction and the number of EC cells per mm 2 of mucosa were significantly increased only in the duodenum. However, the number of EC cells per circular sections of both antrum and small intestine was increased, but reduced both in the ascending and descending colon in D group. The dexamethasone treatment caused a strong reduction in number of granules in the antral EC cells, while it was gradually increased beginning from the jejunum to descending colon. The mean granular content was reduced in the antral EC cells but increased in the jejunal EC cells in D group. In conclusion, the present study showed that morphological changes in gut serotonin-producing EC cells occurred in diabetic rats.