Experimental studies for botulinum toxin type A to antagonist the VIP/PACAP expression on nasal mucosa in allergic rhinitis rat / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the expression and significance of vasoactive intestinal peptide and Pituitary adenylate cyclase activiting polypeptide (VIP/PACAP) of nasal mucosa in rats with allergic rhinitis (AR), and the function of botulinum toxin-A(BTX-A) to inhibit the expression of VIP/PACAP in AR.@*METHOD@#Thirty Sprague-Dawley rats were randomly divided into 3 groups, which were the AR group, the intervention group, and the control group. In the AR group, ovalbumin was used to sensitize healthy rats. In the intervention group, BTX-A was dripped into the nasal cavity of AR rats 7 times. In the control group, only physiological saline was used to drip into the nasal cavity of AR rats. Changes of the rats' behavior were observed. ELISA were used to detected the concentration variation of serum IFN-γ and IL-4. Histopathology and immunohistochemistry were employed to observe morphology in the rats' nasal mucosal and the expression of VIP/PACAP. Statistical analysis was also made.@*RESULT@#(1)The typical symptoms marks of nasal scratching, sneezing, nasal blockage and rhinorrhea of AR group (7.5 ± 0.50) were higher than intervention group (1 ± 0.27) and control group (0.8 ± 0.31). (2) Comparing to intervention group and control group, the serm IFN-γ of the AR group obvious reduced (P < 0.05), the serm IL-4 of the AR group obvious rose (P < 0.01), and the serm Th1/Th2 (IFN-γ/IL-4) of the AR group obvious reduced (P < 0.01). (3) Comparing to intervention group and control group, the cilium loss, inflammatory cells infiltration, and inflammatory cells exudation of nasal mucosa in AR group were more obviously (P < 0.01), and the intervention group of the 3 indexes was obviously than control group. (4) The expression of VIP in the rats' nasal mucosa of the AR group (13.27 ± 2.74) were more intense than intervention group (5.21 ± 2.18) and control group (3.56 ± 5.30) (P < 0.01), and the expression of PACAP in the rats' nasal mucosa of the AR group (20.97 ± 2.14) were more intense than intervention group (6.33 ± 3.04) and control group (4.63 ± 1.25) (P < 0.01). (5) In all the 3 groups, there was positive correlation between expression of negative in VIP/PACAP and Thl/Th2 cell infiltration(r were respectively -0.340 and -0.223, P < 0.05).@*CONCLUSION@#The VIP/PACAP in the rats' nasal mucosa may play an important role in pathogenesis of AR, and BTX-A could improve the symptoms of AR through inhibition of the expression of VIP/ PACAP.

DNA methylation in human papillomavirus-infected cervical cells is elevated in high-grade squamous intraepithelial lesions and cancer / 부인종양

OBJECTIVE: DNA methylation has been shown to be a potential biomarker for early cancer detection. The aim of this study was to evaluate DNA methylation profiles according to liquid-based Pap (LBP) test results and to assess their diagnostic value in a Korean population. METHODS: A total of 205 patients with various Papanicolaou test results were enrolled to this study (negative, 26; atypical squamous cells of undetermined significance, 39; low grade squamous intraepithelial lesion, 44; high grade squamous intraepithelial lesion (HSIL), 48; and cancer, 48). DNA methylation analysis of four genes, ADCYAP1, PAX1, MAL, and CADM1, was performed on residual cervical cells from LBP samples using a quantitative bisulfite pyrosequencing method. To evaluate the diagnostic performance of the four methylated genes for cancer detection, receiver operating characteristic (ROC) curves were drawn. Sensitivities and specificities were also tested at cutoffs determined from the ROC curves. RESULTS: Cervical cancer cells showed dramatically increased methylation levels for the four genes analyzed. ADCYAP1 and PAX1 also trended toward elevated methylation levels in HSIL samples, although the levels were much lower than those in cancer cells. The sensitivities of methylated ADCYAP1, PAX1, MAL, and CADM1 for the detection of cancer were 79.2%, 75.0%, 70.8%, and 52.1%, and the specificities were 92.0%, 94.0%, 94.7%, and 94.0%, respectively. Methylated ADCYAP1 and PAX1 demonstrated relatively better discriminatory ability than did methylated MAL and CADM1 (area under the curves 0.911 and 0.916 vs. 0.854 and 0.756, respectively). CONCLUSION: DNA methylation status, especially in the ADCYAP1 and PAX1 genes, showed relatively good specificity, ranging from 90% to 94%. The possible additive and complementary roles of DNA methylation testing with respect to conventional cervical cancer screening programs will need to be validated in prospective population-based studies.

Pituitary Adenylate Cyclase-activating Polypeptide Inhibits Pacemaker Activity of Colonic Interstitial Cells of Cajal

This study aimed to investigate the effect of pituitary adenylate cyclase-activating peptide (PACAP) on the pacemaker activity of interstitial cells of Cajal (ICC) in mouse colon and to identify the underlying mechanisms of PACAP action. Spontaneous pacemaker activity of colonic ICC and the effects of PACAP were studied using electrophysiological recordings. Exogenously applied PACAP induced hyperpolarization of the cell membrane and inhibited pacemaker frequency in a dose-dependent manner (from 0.1 nM to 100 nM). To investigate cyclic AMP (cAMP) involvement in the effects of PACAP on ICC, SQ-22536 (an inhibitor of adenylate cyclase) and cell-permeable 8-bromo-cAMP were used. SQ-22536 decreased the frequency of pacemaker potentials, and cell-permeable 8-bromo-cAMP increased the frequency of pacemaker potentials. The effects of SQ-22536 on pacemaker potential frequency and membrane hyperpolarization were rescued by co-treatment with glibenclamide (an ATP-sensitive K+ channel blocker). However, neither N(G)-nitro-L-arginine methyl ester (L-NAME, a competitive inhibitor of NO synthase) nor 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (ODQ, an inhibitor of guanylate cyclase) had any effect on PACAP-induced activity. In conclusion, this study describes the effects of PACAP on ICC in the mouse colon. PACAP inhibited the pacemaker activity of ICC by acting through ATP-sensitive K+ channels. These results provide evidence of a physiological role for PACAP in regulating gastrointestinal (GI) motility through the modulation of ICC activity.

Expression and regulation of pituitary adenylate cyclase-activating polypeptide mRNA in pregnant rat corpus luteum / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the expression changes and regulation of pituitary adenylate cyclase-activating polypeptide (PACAP) mRNA in corpus luteum during pregnancy.</p><p><b>METHODS</b>Pregnant rats' ovaries were collected at different time points. The techniques of RT-PCR and in situ hybridization were used to observe expression changes of PACAP mRNA in rat ovaries during pregnancy. To further explore the regulation mechanism of PACAP mRNA expression in corpus luteum, luteal cells were cultured in vitro. Immature (25 - 28 days old) female Sprague-Dawley rats were injected subcutaneously with 50IU pregnant mare serum gonadotrophin (PMSG), and 25IU human chorionic gonadotrophin (hCG) 48 h later, to induce follicular development and luteum formation. On day 6 after hCG administration (the day of hCG administration was the first day), the rats were killed by guillotine and the ovarian luteal cells were collected. After incubation for 24 h, luteal cells were administration with various factors for 24 h. And then expression changes of PACAP mRNA in luteal cells after administration with different factors were detected by RT-PCR, and radioimmunoassay was used to analyze progesterone levels.</p><p><b>RESULTS</b>With the development of pregnancy, the expression of PACAP mRNA increased gradually, reached the peak at pregnancy 19 d, and then decreased. Compared with control group, platelet activating factor (PAF), forskolin and PMA could obviously stimulate PACAP mRNA expression in luteal cells which were cultured with corresponding factors for 24 h. At the same time, progesterone levels in culture media were also elevated.</p><p><b>CONCLUSION</b>PACAP, acting as a local ovary regulator, was closely related to the maintenance of medium-term and late pregnancy. PAF could directly stimulate PACAP mRNA expression in luteal cells, and protein kinase C (PKC) and protein kinase A (PKA) signal pathways could both participate in this process.</p>

Expression and characterization of VPAC2 in CHO cells / 生物工程学报

VPAC2 is a co-receptor of pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) and mediates multiple bio-functions. In order to construct the CHO line expressing VPAC2 stably, pcDNA-VPAC2 was used to transfect CHO cells. The positive clones were selected by G418 and the clone VPAC2-CHO with high sensitivity to PACAP38 was picked out by its ability to promoting the concentration of cAMP. RT-PCR, Western blot and Immunofluorescenece assay were used to identify the express of VPACS. Binding competition with VPAC2 agonist and the bioactivity of mediating the ligand to promote the concentration of cAMP showed that VPAC2 was expressed effectively in VPAC2-CHO. The results of Scatchard analysis revealed that VAPC2-CHO expressed a receptor density of (1.1 +/- 0.2) pmol/mg protein, respectively, with Kd values of (0.55 +/- 0.10) nmol/L for PACAP38 used as a tracer. The construction of CHO cells expressing VPAC2 specially and functionally lays a foundation not only for the further research on the characters and functions of VPAC2 but also for the screening and characterization of novel agonists of antagonists for VPAC2.

Determination of differentially expressed proteins and it's significance among chronic sinusitis, nasal polyps and normal nasal mucosa / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the differentially expressed proteins among chronic sinusitis, nasal polyps and normal nasal mucosa by means of proteomic technology, and select the candidate biomarkers of chronic sinusitis and nasal polyps.</p><p><b>METHODS</b>Proteins extracted from chronic sinusitis, nasal polyps and normal nasal mucosa were separated and the differentially expressed proteins were identified by series of proteomic tools, including immobilized pH4-7 gradient two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis, modified coomassie brilliant blue staining, images scanning by the Image Scanner apparatus, PDQuest analysis software, peptide mass fingerprinting based on matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) by in-gel digestion extract, and Mascot searching in NCBInr and SWISS-PROT databases.</p><p><b>RESULTS</b>The 2-DE patterns with high resolution and reproducibility were obtained. The protein spots separated and visualized in chronic sinusitis, nasal polyps and normal nasal mucosa gel were 1020 +/- 40, 1112 +/- 10 and 1008 +/- 25, respectively. And the match rates were (93 +/- 2)%, (95 +/- 1)% [see text] (90 +/- 3)% respectively. Thirteen differentially expressed spots were found from chronic sinusitis, nasal polyps and normal nasal mucosa gel. We selected and recommend Keratin 8 and APOA1 proteins as candidate biomarkers of nasal polyps, and PLUNC protein, PACAP protein, NKEF-B and SOD as candidate biomarkers of chronic sinusitis.</p><p><b>CONCLUSIONS</b>The differentially expressed proteins among chronic sinusitis, nasal polyps and normal nasal mucosa can be efficiently and relatively reliably identified via the techniques of proteomics. These techniques will play a very important role in the researches for new objective indicators possibly employed in the future classifying, staging and prognosis.</p>

Control Mechanisms of Ovarian Follicle Development by Follicle Stimulating Hormone and Pituitary Adenylate Cyclase-activating Polypeptide / 대한불임학회지

OBJECTIVE: Pituitary adenylate cyclase-activating polypeptide (PACAP), a novel hypothalamic neuropeptide, has been suggested to play a role in ovarian folliculogenesis. The present study evaluated the effect of PACAP on the growth of preantral follicles. METHODS: Preantral follicles were mechanically isolated from ovaries of 21-day-old rats and cultured in groups for 3 days in serum-free medium in the absence or presence of PACAP-38 (10-6 M). RESULTS: Treatment with PACAP-38 resulted in an increase in follicle diameter by 75% whereas treatment with follicle stimulating hormone (FSH) increased follicle diameter by 65%. PACAP-38 treatment enhanced the granulosa cell proliferation as measured by thymidine incorporation analysis. Furthermore, the production of progesterone by cultured granulosa cells and GFSHR-17 cell line was stimulated by PACAP-38. Interestingly, PACAP enhanced FSH action on stimulation of SF-1 and aromatase gene expression. CONCLUSION: The present results demonstrate that PACAP stimulated preantral follicle growth by potentiating proliferation and by stimulating steroidogenesis.

Expression of pituitary adenylate cyclase activating polypeptide and its type I receptor mRNAs in human placenta

Pituitary adenylate cyclase activating polypeptide (PACAP) was first isolated from ovine hypothalamus and was known to stimulate the release of growth factor in various cells. Recently, we reported the cellular localization of PACAP and its type I (PAC1 ) receptor in rat placenta during pregnancy. Placenta is a critical organ that synthesizes several growth factors and angiogenic factors for the fetal development and its own growth. However, there is little information regarding the cellular localization of PACAP and its receptor in human placenta at various gestations. The aim of the present study was to define the expression and distribution of PACAP and PAC1 receptor mRNAs in the human placenta during the pregnancy period. PACAP and PAC1 receptor mRNAs were expressed in stroma cells of stem villi and terminal villi. At the early stage, on 7 and 14 weeks, PACAP and PAC1 receptor genes were moderately expressed in stroma cells surrounding the blood vessels within stem villi. These genes were strongly expressed in stroma cells of stem villi and terminal villi on 24 and 38 weeks. The expression of these genes was increased as gestation advanced, and localized in the same areas. Localization of PACAP and PAC1 receptor demonstrate the evidence that PACAP may play an important role, as an autoregulator or pararegulator via its PAC1 receptor. In conclusion, our findings strongly suggest that PACAP may have a critical role in physiological function of the placenta for gestational maintenance and fetal growth.

Control Mechanisms of Ovulation by Pituitary Adenylate Cyclase-Activating Polypeptide / 대한불임학회지

No abstract available.

Regulation of Prolactin Gene Expression by Hypothalamic Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) in the Female Rat Pituitary Gland / 대한내분비학회지

BACKGROUND: Pituitary adenylate cyclase-activating polypeptide (PACAP) plays the role of a hypophysiotropic factor, which regulates the synthesis and secretion of pituitary hormones through the hypothalamo-hypophysial portal system. No clear evidence has yet been reported regarding the regulation of prolactin (PRL) by PACAP. In the present study, we tested a hypothesis that PACAP regulates the synthetic machinery of PRL during the estrus cycle and pubertal process using intracerebroventricular (i.c.v.) injection of an antisense oligodeoxynucleotide (ODN) against type I PACAP receptor (PAC1). METHODS: An RNase protection assay (RPA) was used to determine the pattern of hypothalamic PACAP and PAC1 mRNA expressions during the estrus cycle. Antisense PAC1 ODN was administered via i.c.v. injection to the female rats in normal estrus cycle of pubertal process. Northern blot analysis was used to determine the mRNA ievel of PRL in the pituitary gland. RESULTS: 1) PACAP mRNA in the medial basal hypothalamus was significantly increased at the diestrus I, while PAC1 mRNA showed no significant change. 2) PRL mRNA level of pituitary was increased by an injection of antisense PAC1 ODN at the proestrus and estrus stages. 3) PRL mRNA level of pituitary was significantly decreased by antisense PAC1 ODN injection at stage of prepuberty and initiate puberty, while its level was increased at stage of puberty. CONCLUSION: These data suggest that PACAP suppresses PRL mRNA synthesis through the PAC1 signaling pathway in the certain estrus cycle environments. It may be also involved in the regulation of pituitary PRL gene expression during the pubertal process

Pituitary adenylate cyclase activating polypeptide protects neuro-2a cells from beta amyloid protein cytotoxicity by modulating intracellular calcium / 生理学报

MTT analysis and intracellular calcium measurement by using confocal laser scanning microscopy were used to study the possible mechanism of protective effect of pituitary adenylate cyclase activating polypeptide 27 (PACAP27) from beta amyloid protein (Abeta)-induced neurotoxicity. The results showed that treatment with PACAP (less than 0.1 micromol/L) increased the survival and reproductive ability of neuro-2a cells and protected the neuro-2a cells from being injured by Abeta. The protective effect of PACAP27 was reversed by the competitive PACAP receptor antagonist PACAP6-27. An increase in intracellular calcium was observed when the cells were challenged with Abeta and PACAP. But the calcium increase induced by Abeta kept stable for a long time while PACAP caused a transient rise in intracellular calcium. The intracellular calcium increase induced by Abeta was blocked by pretreatment with PACAP for 10 min. It is suggested that the neuroprotective effect of PACAP against neuronal damage induced by Abeta may result from its role in inhibiting the sustained rise in intracellular calcium.

Interaction of Pituitary Adenylate Cyclase-Activating Polypeptide and Angiotensin II on Aldosterone Production in Human Adrenocortical H295R Cells / 대한내분비학회지

BACKGROUND: Evidence is accumulating that aldosterone secretion can be regulated in a paracrine and/or an autocrine manner by several neuropeptides locally released within the adrenal gland. Among neuropeptides, pituitary adenylate cyclase-activating polypeptide (PACAP) is present in high concentration in the human adrenal gland. The purpose of this study was to investigate the action of PACAP and the interaction between PACAP and angiotensin II (AII), the main physiologic aldosterone secretagogue, in aldosterone production in human H295R adrenocortical cells. METHODS: H295R cells were incubated with increasing concentrations of PACAP (10(-11)M~10(-7)M) in the absence or presence of 10(-7)M AII. Aldosterone concentration in the supernatant was determined by RIA. Intracellular cAMP content was measured by RIA and total inositol phosphate (IP) production by anion exchange chromatography. Gene expression of CYP11B2 was studied by RT-PCR. RESULTS: In H295R cells, PACAP stimulated aldosterone production in a dose-dependent manner. Incubation of H295R cells with PACAP in the presence of AII significantly increased aldosterone production, compared with that of PACAP alone. PACAP dose-dependently increased cAMP production, but 10(-7)M AII had no effect on either basal or PACAP-stimulated cAMP production. Total IP production was not affected by PACAP, but was increased by 10(-7)M AII; an increase that was not further increased by addition of PACAP. RT-PCR analysis of H295R cells which were exposed to 10-7M PACAP or 10(-7)M AII showed an increase in CYP11B2 transcript signal. Induction of CYP11B2 mRNA expression in response to treatment with both PACAP and AII was significantly more than that resulting from using PACAP alone. CONCLUSION: The present study demonstrates that PACAP exerts a direct stimulatory effect on aldosterone production through induction of CYP11B2 mRNA expression by adenylate cyclase activation as the main intracellular signal pathway in H295R cells. Furthermore, there may be some additive effects between PACAP and AII on aldosterone production.

Relationship between amyloid beta-protein and oxidative stress and the protective role of pituitary adenylate cyclase activating polypeptide against oxidative stress induced damage on neuro-2a cells / 中国应用生理学杂志

<p><b>AIM</b>To observe the relationship between amyloid beta-protein (Abeta) and oxidative stress and the protective role of pituitary adenylate cyclase activating polypeptide (PACAP, PACAP-27) against damage induced by oxidative stress (H2O2) in neurem-2a cells.</p><p><b>METHODS</b>With cultured neuro-2a cells the cell survival and apoptosis were measured by MTT assay, Hoechest33258 staining, DNA ladder and the percentage of small DNA fragment.</p><p><b>RESULTS</b>Concentration-dependent toxicity was induced with H2O2 treatment for 24 h. The neurotoxicity of H2O2 was increased by about 10 times with cotreatment neurons with amyloid beta-protein fragment 25-35 (Abeta(25-35)). While decrease the percentage of small DNA fragmentation the cell survival was increased with co-treatment with PACAP-27(which were added to the culture everyday). The effect of PACAP was not reversed with antagonist of PACAP receptor, PACAP(6-27).</p><p><b>CONCLUSION</b>Abeta and H2O2 can promote each other's neurotoxicity. Cultured neurons were protected by PACAP27 from the neurotoxicity of H2O2 but not through the activation of PACAP-27 receptor.</p>

Experimental study of pituitary adenylate cyclase activating polypeptide on relieving brain edema induced by ischemia in rats / 中国应用生理学杂志

<p><b>AIM</b>In order to study the effects of pituitary adenylate cyclase activating polypeptide(PACAP) on brain edema induced by ischemia in rats and its underlying receptor mechanism.</p><p><b>METHODS</b>Brain ischemia model in rats was established by ligaturing four--vessels. The percentage ratio of wet over dry tissue weight, sodium and potassium contents of dry brain tissue were measured by weighing and enzymatic analysis methods.</p><p><b>RESULTS</b>The brain water contents significantly increased after rats exposed to 1 h of reperfusion following 30 - minute ischemia. Furthermore, sodium contents in brain tissue increased and potassium contents decreased following perfusion. Changes of brain water contents, sodium and potassium contents were relieved by lateral ventricular injection of PACAP in the concentration of 1 x 10(-9), 1 x 10(-10) or 1 x 10(-11) mol respectively before ischemia. The effect of PACAP could be blocked by MCAP6 - 38 (specific type I PACAP receptor antagonist) lateral ventricular injection prior to PACAP administration.</p><p><b>CONCLUSION</b>Exogenous PACAP may act as a protective effect in brain edema induced by ischemia in rats, which is mediated by type I receptor.</p>

Role of Pituitary Adenylate Cyclase Activating Polypeptide-(1-27) in the Clitorial Cavernosum Smooth Muscle / 대한비뇨기과학회지

PURPOSE: Pituitary adenylate cyclase-activating polypeptide (PACAP) showed the relaxant effect and distribution patterns in the penile corpus cavernosum. We investigated the presence, distribution, and effects of PACAP-(1-27) in the clitoral cavernosum (CC). MATERIALS AND METHODS: The isometric tension was measured in the strip of rabbit CC. Immunohistochemistry was used to localize PACAP-(1-27) immunoreactivity in nerve fibers in CC. Possible co-localization of the PACAP-(1-27) immunoreactive nerve fiber with other nerve fiber was investigated by application of double immunofluorescent labeling technique using antibody to protein gene product 9.5 (PGP 9.5). Western blotting was used to identify the expression of PACAP-(1-27) protein. RESULTS: The pre-contracted CC smooth muscle strip with phenylephrine was relaxed dose-dependently with PACAP-(1-27). PACAP-(6-27), PACAP-(1-27) receptor antagonist did not affect the PACAP-(1-27) induced relaxant responses. Pre-treatment with Nw- nitro-L-arginine methyl ester (NO synthase inhibitor) did not affect the relaxation induced by PACAP-(1-27). CC was not stained by anti-human PACAP-(1-27) guinea pig polyclonal antibody and the immunoreactivity for anti-human PGP 9.5 mouse monoclonal antibody was observed throught the CC. Western blotting demonstrated the presence of immunoreactive protein band corresponding to 35 KDa PACAP-(1-27). CONCLUSIONS: The present study shows that PACAP-(1-27) has a possible role in the modulation of smooth muscle tone of the CC resulting in erection.

Stimulation by EGF, bFGF and GnRH of Ovarian Pituitary Adenylate Cyclase-Activating Polypeptide Gene Expression in Cultured Rat Preovulatory Follicles / 대한불임학회지

No abstract available.

Vasoactive Intestinal Peptide/Pituitary Adenylate Cyclase Activating Peptide Receptor Subtypes in Neuroblastoma, Stomach Cancer / 대한소아혈액종양학회지

PURPOSE: We analyzed the expression of vasoactive intestinal peptide (VIP), pituitary adenylate cyclase activating peptide (PACAP), VIP receptor 1 (VIPR1), VIP receptor 2 (VIPR 2) and PACAP receptor (PACAPR) genes in human neuroblastoma, neuroblastoma cell line, human stomach cancer, and human stomach cancer cell lines using RT-PCR and Sourthern hybridization. The results should permit identification of potential clinical applications for VIP and PACAP. METHODS: We isolated RNA from 1 neuroblastoma cell line, 8 stomach cancer cell lines, 13 neuroblastoma, and 10 stomach cancer tumor specimens. And then we performed RT-PCR, Sourthern hybridization, and sequencing. RESULTS: We detected the RNAs coding for VIP, VIPR1, VIPR2, PACAP, and PACAPR in 1, 11, 2, 12, and 13 out of 13 neuroblastoma tumor specimens, respectively. VIP and PACAPR RNA was expressed in SKNSH. VIPR1 RNA was expressed in 4 of 8 the stomach cancer cell lines and 6 of 10 stomach cancer tumor specimens. CONCLUSION: VIP/PACAP RNA and VIP/PACAP receptors RNA were expressed in SKNSH and neuroblastoma tumor specimens. VIPR1 was expressed in stomach cancer cell lines and tumor specimens. The present results suggested that VIP/PACAP analogues could be a candidate as the growth inhibitor of neuroblastoma and stomach cancer.

Mechanism of pituitary adenylate cyclase-activating polypeptide-induced inhibition on catecholamine secretion evoked by cholinergic stimulation and membrane depolarization in the rat adrenal gland

The present study was attempted to examine the effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on catecholamine (CA) secretion evoked by cholinergic stimulation, membrane depolarization and calcium mobilization from the isolated perfused rat adrenal gland. The perfusion of PACAP (10 nM) into an adrenal vein for 60 min produced a great inhibition in CA secretion evoked by ACh (5.32 X 10(-3) M), high K+ (5.6 X 10(-2) M), DMPP (10(-4) M for 2 min), McN-A-343 (10(-4) M for 2 min), cyclopiazonic acid (10(-5) M for 4 min) and Bay-K-8644 (10(-5) M for 4 min). Also, in the presence of neuropeptide (NPY), which is known to be co-localized with norepinephrine in peripheral sympathetic nerves, CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly depressed. However, in adrenal glands preloaded with PACAP (10 nM) under the presence of VIP antagonist ((Lys1, Pro2.5, Arg3.4, Tyr6)-VIP (3 micrometer)) for 20 min, CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were not altered greatly in comparison to the case of PACAP-treatment only. Taken together, these results suggest that PACAP causes the marked inhibition of CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization, indicating that this effect may be mediated by inhibiting influx of extracellular calcium and release in intracellular calcium in the rat adrenomedullary chromaffin cells.