ABSTRACT
PROPOSE: We aimed to explore the potential molecular mechanism and independent prognostic genes for colon cancer (CC). METHODS: Microarray datasets GSE17536 and GSE39582 were downloaded from Gene Expression Omnibus. Meanwhile, the whole CC-related dataset were downloaded from The Cancer Genome Atlas (TCGA) database. Differentially expressed mRNA (DEMs) were identified between cancer tissue samples and para-carcinoma tissue samples in TCGA dataset, followed by the KEGG pathway and GO function analyses. Furthermore, the clinical prognostic analysis including overall survival (OS) and disease-free survival (DFS) were performed in all three datasets. RESULTS: A total of 633 up- and 321 down-regulated mRNAs were revealed in TCGA dataset. The up-regulated mRNAs were mainly assembled in functions including extracellular matrix and pathways including Wnt signaling. The down-regulated mRNAs were mainly assembled in functions like Digestion and pathways like Drug metabolism. Furthermore, up-regulation of UL16-binding protein 2 (ULBP2) was associated with OS in CC patients. A total of 12 DEMs including Surfactant Associated 2 (SFTA2) were potential DFS prognostic genes in CC patients. Meanwhile, the GRP and Transmembrane Protein 37 (TMEM37) were two outstanding independent DFS prognostic genes in CC. CONCLUSIONS: ULBP2 might be a potential novel OS prognostic biomarker in CC, while GRP and TMEM37 could be served as the independent DFS prognostic genes in CC. Furthermore, functions including extracellular matrix and digestion, as well as pathways including Wnt signaling and drug metabolism might play important roles in the process of CC.
Subject(s)
Humans , Animals , Colonic Neoplasms/diagnosis , Colonic Neoplasms/genetics , Gene Expression Profiling/methods , RNA, Messenger/genetics , RNA, Messenger/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Genetic Markers , Down-Regulation/genetics , Gene Expression Regulation, Neoplastic , Up-Regulation/genetics , Risk Factors , Colonic Neoplasms/metabolism , Disease-Free Survival , Gastrin-Releasing Peptide/genetics , Gastrin-Releasing Peptide/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Pulmonary Surfactant-Associated Protein A/genetics , Pulmonary Surfactant-Associated Protein A/metabolism , Microarray Analysis , Murinae , Kaplan-Meier Estimate , GPI-Linked Proteins/genetics , GPI-Linked Proteins/metabolismABSTRACT
Abstract Objective: To evaluate the safety, tolerability and potential therapeutic effects of gastrin-releasing peptide in three children with autistic spectrum disorder. Methods: Case series study with the intravenous administration of gastrin-releasing peptide in the dose of 160 pmol/kg for four consecutive days. To evaluate the results, parental impressions the Childhood Autism Rating Scale (CARS) and the Clinical Global Impression (CGI) Scale. Each child underwent a new peptide cycle after two weeks. The children were followed for four weeks after the end of the infusions. Results: The gastrin-releasing peptide was well tolerated and no child had adverse effects. Two children had improved social interaction, with a slight improvement in joint attention and the interaction initiatives. Two showed reduction of stereotypes and improvement in verbal language. One child lost his compulsion to bathe, an effect that lasted two weeks after each infusion cycle. Average reduction in CARS score was 2.8 points. CGI was "minimally better" in two children and "much better" in one. Conclusions: This study suggests that the gastrin-releasing peptide is safe and may be effective in improving key symptoms of autism spectrum disorder, but its results should be interpreted with caution. Controlled clinical trials-randomized, double-blinded, and with more children-are needed to better evaluate the possible therapeutic effects of gastrin-releasing peptide in autism.
Resumo Objetivo: Avaliar a segurança, a tolerabilidade e os possíveis efeitos terapêuticos do peptídeo liberador de gastrina em três crianças com transtorno do espectro autista. Métodos: Estudo de casuística com administração intravenosa de peptídeo liberador de gastrina na dose de 160 pmol/kg por quatro dias consecutivos. Para avaliar os resultados, foram usadas a impressão dos pais, a Escala de Classificação de Autismo na Infância (CARS) e a Escala de Impressão Clínica Global (CGI). Cada criança foi submetida a novo ciclo de peptídeo após duas semanas. As crianças foram acompanhadas por quatro semanas após o término das infusões. Resultados: O peptídeo liberador de gastrina foi bem tolerado e nenhuma criança apresentou efeitos adversos. Duas crianças apresentaram melhoria na interação social, com melhoria na atenção compartilhada e nas iniciativas de interação. Duas mostraram redução dos estereótipos e melhoria na linguagem verbal. Uma criança perdeu sua compulsão por banhos, efeito que durou duas semanas após cada ciclo de infusão. A redução média no escore da CARS foi de 2,8 pontos. Quanto à CGI, os resultados foram "minimamente melhor em duas crianças" e "muito melhor" em uma. Conclusões: Este estudo sugere que o peptídeo liberador de gastrina é seguro e pode ser efetivo na melhoria dos principais sintomas do transtorno do espectro autista, porém seus resultados devem ser interpretados com cautela. Ensaios clínicos controlados, randomizados, duplo-cegos e com maior número de crianças são necessários para melhor avaliar os possíveis efeitos terapêuticos do peptídeo liberador de gastrina sobre o autismo.
Subject(s)
Humans , Male , Child, Preschool , Gastrin-Releasing Peptide/administration & dosage , Autism Spectrum Disorder/drug therapy , Treatment Outcome , Administration, Intravenous , Autism Spectrum Disorder/diagnosisABSTRACT
Pancreatic adenocarcinoma is important in oncology because of its high mortality rate. Deaths may be avoided if an early diagnosis could be achieved. Several types of tumors overexpress gastrin-releasing peptide receptors (GRPr), including pancreatic cancer cells. Thus, a radiolabeled peptide derivative of gastrin-releasing peptide (GRP) may be useful as a specific imaging probe. The purpose of the present study was to evaluate the feasibility of using99mTc-HYNIC-βAla-Bombesin(7-14)as an imaging probe for Capan-1 pancreatic adenocarcinoma. Xenographic pancreatic tumor was developed in nude mice and characterized by histopathological analysis. Biodistribution studies and scintigraphic images were carried out in tumor-bearing nude mice. The two methods showed higher uptake by pancreatic tumor when compared to muscle (used as control), and the tumor-to-muscle ratio indicated that99mTc-HYNIC-βAla-Bombesin(7-14)uptake was four-fold higher in tumor cells than in other tissues. Scintigraphic images also showed a clear signal at the tumor site. The present data indicate that99mTc-HYNIC-βAla-Bombesin(7-14)may be useful for the detection of pancreatic adenocarcinoma.
Subject(s)
Animals , Humans , Male , Adenocarcinoma , Bombesin/analogs & derivatives , Organotechnetium Compounds/pharmacokinetics , Pancreatic Neoplasms , Adenocarcinoma/pathology , Bombesin/pharmacokinetics , Cell Line, Tumor , Gastrin-Releasing Peptide/analogs & derivatives , Heterografts/pathology , Heterografts , Mice, Nude , Muscles , Pancreatic Neoplasms/pathology , Peptide Fragments/pharmacokineticsABSTRACT
A collection of neurons in the upper lumbar spinal cord (lumbar segments 3 and 4) of male rats project to the lower lumbar spinal cord (lumbar segments 5 and 6) and release a gastrin-releasing peptide (GRP) to the somatic and autonomic regions, which are known to regulate male sexual reflexes. The GRP plays some special functions when bound to the specific GRP receptor (GRPR). The spinal GRP system is regulated by androgens. Accumulating evidence shows that GRP plays an important role in rat penile erection and ejaculation, and pharmacological stimulation of GRPRs with a specific agonist can restore penile reflexes and ejaculation in castrated male rats. Therefore, the GRP system appears to be a potential therapeutic target for the treatment of erectile dysfunction or ejaculatory dysfunction. The present paper briefly reviews the recent studies on the role of the spinal GRP system in regulating the sexual function of males.
Subject(s)
Animals , Male , Rats , Androgens , Metabolism , Ejaculation , Physiology , Gastrin-Releasing Peptide , Metabolism , Physiology , Penile Erection , Physiology , Spinal Cord , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To evaluate the value of plasma ProGRP, CYFRA 21-1 and CEA in patients with lung cancer.</p><p><b>METHODS</b>The levels of plasma ProGRP, CYFRA 21-1 and CEA were detected in 85 healthy control, 49 benign lung diseases and 143 lung neoplasms. The levels of ProGRP in the patients with SCLC was monitored.</p><p><b>RESULTS</b>The level of plasma ProGRP in SCLC (M 179.1 ng/ml) was significantly higher than adenocarcinoma (M 35.3 ng/ml), squamous-cell carcinoma (M 33.3 ng/ml), healthy control (M 35.6 ng/m) and benign lung diseases (M 33.3 ng/m), P < 0.001. The sensitivity and specificity for diagnosing SCLC by ProGRP were 60.6% and 95.0% respectively. In the effective treatment group, ProGRP reduced 45.9%, in the progression group, ProGRP increased 103.1%, P < 0.05. The level of CEA in the metastatic adenocarcinoma (M 10.22 ng/ml) was significantly higher than non-metastatic adenocarcinoma (M 3.85 ng/ml) and squamous cell carcinoma (M 2.56 ng/ml) (P < 0.01).</p><p><b>CONCLUSION</b>The plasma ProGRP is a good indicator for diagnosing and evaluating cure effect in SCLC; the high expression of CEA is related to the metastatic adenocarcinoma.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Antigens, Neoplasm , Blood , Carcinoembryonic Antigen , Blood , Case-Control Studies , Diagnostic Techniques and Procedures , Gastrin-Releasing Peptide , Blood , Keratin-19 , Blood , Lung Neoplasms , Blood , Diagnosis , Small Cell Lung Carcinoma , Blood , DiagnosisABSTRACT
Bombesin [BN], a 14-amino acid neuropeptide, shows high affinity for the human GRP [gastrin releasing peptide] receptors, which are overexpressed by a variety of cancers, including prostate, breast, pancreas, gastrointestinal, and small cell lung cancer. Aim was to prepare [6-hydrazinopyridine-3-carboxylic acid [HYNIC[0], D-Tyr[6], D-Trp[8]] - BN [6-14] NH[2] that could be easily labeled with[99m]Tc and evaluation of its potential as an imaging agent. Synthesis of the peptide amide was carried out onto Rink Amide MB HA [4-Methylbenzhydrylamine] resin. A bifunctional chelating agent [BFCA] was attached to the N terminal peptide in solid-phase. [99m]Tc labeling was performed by addition of sodium pertechnetate to solution that include [HYNIC[0], D-Tyr[6], D-Trp[8]] Bombesin [6-14] NH[2], tricine, ethylenediamine-N,N'-diaeetic acid [EDDA] and SnCl[2]. Radiochemical evaluation was carried out by reverse phase high-performance liquid chromatography [HPLC] and instant thin layer chromatography [ITLC]. In- vitro internalization was tested using human prostate cancer cells [PC-3] with blocked and non-blocked receptors. Biodistribution was determined in rats. [99m]Tc/tricine/EDDA-HYNIC[0], D-Tyr[6], D-Trp[8]] bombesin [6-14] NH[2] was obtained with radiochemical purities >98%. Results of in-vitro studies demonstrated a high stability in serum and suitable internalization. Biodistribution data showed a rapid blood clearance, with renal excretion and specific binding towards GRP receptor-positive tissues such as pancreas. In this study, labeling of this novel conjugate with [99m] Tc easily was performed using coligand. The prepared [99m]Tc-HYNIC-BN conjugate has promising characteristics for the diagnosis of malignant tumors
Subject(s)
Acetanilides , Aza Compounds , Technetium , Gastrin-Releasing Peptide , Receptors, Bombesin , Hydrazines , Nicotinic Acids , Benzhydryl Compounds , Chromatography, High Pressure Liquid , Edetic Acid/analogs & derivatives , Edetic Acid , Neoplasm ProteinsABSTRACT
El péptido bombesina (BN), de 14 amino ácidos, se aisló de la piel de los batracios y forma parte de un amplio grupo de neuropéptidos con diversas funciones biológicas. El homólogo equivalente en los mamíferos es el péptido liberador de la gastrina (GRP) y sus receptores (GRP-r) se expresan abundantemente en la membrana de las células tumorales, estimulando su crecimiento. La unión BN-GRP-r es una fuerte unión altamente específica por lo cual la BN marcada con radionucleidos se ha utilizado en medicina nuclear para la localización de tumores malignos de cáncer de mama y próstata principalmente. Las modificaciones en la cadena peptídica y el marcado se llevan a cabo en la región de extremo-N inicial, quedando el extremo C-terminal con su especificidad y acción biológica intactas. Se presentan varios análogos de BN radiactivos y la estructura de uno nuevo formado por un conjugado EDDA/HYNIC-BBN que fácilmente se une al 99mTc. Las expectativas para utilizar radiofármacos de BN marcados con emisores beta-negativos en radiopéptidoterapia son grandes y prometedoras.
Subject(s)
Humans , Bombesin/analogs & derivatives , Bombesin/pharmacology , Gastrin-Releasing Peptide/analogs & derivatives , Gastrin-Releasing Peptide/pharmacology , Receptors, Bombesin/metabolism , Bombesin , Bombesin/therapeutic use , Molecular Sequence Data , Neoplasms/diagnosis , Neoplasms/radiotherapy , Gastrin-Releasing Peptide , Gastrin-Releasing Peptide/therapeutic use , Radiopharmaceuticals , Radiopharmaceuticals/therapeutic use , Structure-Activity RelationshipABSTRACT
<p><b>OBJECTIVE</b>To study the expression of gastrin(GAS) and gastrin releasing peptide(GRP) in patients with gastric cancer and investigate the clinical significance.</p><p><b>METHODS</b>The expression of GAS and GRP in sixty patients with gastric cancer was detected by using tissue chip technique and immunohistochemical methods.</p><p><b>RESULTS</b>The positive rates of GAS and GRP were 30.0% and 11.7% respectively in 60 cases with gastric cancer. The positive rates of GAS and GRP were higher in moderately and poorly differentiated cancers than those in well differentiated cancer (P< 0.05). The positive rates of GAS and GRP were significantly higher in mucinous adenocarcinoma and signet-ring cell carcinoma than those in other types of gastric cancer (P< 0.05). The positive expression of GAS and GRP in gastric cancer was correlated with lymph node metastasis (P< 0.05).</p><p><b>CONCLUSION</b>Tissue chip technique is a feasible,rapid,economic and accurate approach for screening clinical tissue specimens on a large scale.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Gastrin-Releasing Peptide , Metabolism , Gastrins , Metabolism , Immunohistochemistry , Methods , Neoplasm Invasiveness , Neoplasm Staging , Protein Array Analysis , Stomach Neoplasms , Metabolism , PathologyABSTRACT
<p><b>OBJECTIVE</b>To evaluate five serum tumor markers used alone or in combination for the diagnosis of lung cancer.</p><p><b>METHODS</b>The level of five serum tumor markers: NSE, pro-GRP, CYFRA21-1, p53 antibody and CEA was detected by ELISA in 50 healthy adults, 170 lung cancer patients and 60 patients with respiratory infection.</p><p><b>RESULTS</b>The level of the five serum tumor markers in lung cancer patients was significantly higher than that of healthy adults and patients with respiratory infection (P < 0.01). The level of NSE and pro-GRP in patients with small-cell lung cancer was significantly higher than those of the other subtypes of lung cancer (P < 0.01); The level of CYFRA21-1 in patients with squamous-cell carcinoma was significantly higher than that of other subtypes (P < 0.01). The specificity of p53 antibody was 100% in diagnosing lung cancer and the sensitivity of NSE, pro-GRP was much higher for small-cell lung cancer than for other subtypes (P < 0.01); The same was observed in CYFRA21-1 for the diagnosis of squamous-cell carcinoma (P < 0.01). The sensitivity of the tumor markers in diagnosing lung cancer was significantly enhanced if used in combination (P < 0.01).</p><p><b>CONCLUSION</b>These five tumor markers are valuable auxiliary parameters in diagnosing lung cancer. The combination of NSE and pro-GRP is more appropriate than other combinations in diagnosing small-cell lung cancer; the combination of CYFRA21-1, CEA and p53 antibody is the most valuable combination for diagnosing non-small-cell lung cancer. p53 antibody has the highest specificity for diagnosing lung cancer; CYFRA21-1 is the most valuable parameter for diagnosing squamous carcinoma.</p>
Subject(s)
Female , Humans , Male , Middle Aged , Adenocarcinoma , Diagnosis , Antibodies, Neoplasm , Blood , Antigens, Neoplasm , Blood , Biomarkers, Tumor , Blood , Carcinoembryonic Antigen , Blood , Carcinoma, Squamous Cell , Diagnosis , Gastrin-Releasing Peptide , Blood , Keratin-19 , Keratins , Blood , Lung Neoplasms , Diagnosis , Phosphopyruvate Hydratase , Blood , Tumor Suppressor Protein p53 , Allergy and ImmunologyABSTRACT
PURPOSE: Bombesin-like peptides are known to be important in the autocrine growth of a number of small cell lung cancer cell lines. The aim of this study was to investigate the extent of bombesin family ligands/receptors expression in human gastric cancer tissues and cell lines, and to evaluate the relationship between the expression of bombesin family ligands/receptor and clinicopathologic parameters. METHODS: We measured the expression of gastrin releasing peptide (GRP), neuromedin B (NMB), and their receptors, in human gastric cancer tissues and cell lines. Ligand and receptor mRNA studies were carried out on; 20 tumor and matched normal samples, and 9 gastric cell lines. The expression of mRNA of GRP/NMB, and their receptors, was examined by the reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Expression of GRP, NMB and GRPR, NMBR mRNA was found in 55%, 100%, 40%, and 100% of gastric cancer tissue, respectively. GRP/GRPR co-expression was observed in 30% of gastric cancer tissues and expression of gastric cancer was higher than that of normal mucosa. GRP and GRPR were highly expressed in the differentiated type of gastric cancer. In gastric cancer cell lines, these peptides and receptors were expressed equally. CONCLUSION: The result demonstrate that GRP, NMB, GRPR, and NMBR were expressed in gastric cancer tissues and cell lines. This result suggests that these may have a role as growth factors in gastric cancer growth, and these peptides may act in an autocrine fashion as a morphogen in gastric cancer.
Subject(s)
Humans , Humans , Bombesin , Cell Line , Gastrin-Releasing Peptide , Intercellular Signaling Peptides and Proteins , Ligands , Mucous Membrane , Peptides , RNA, Messenger , Small Cell Lung Carcinoma , Stomach NeoplasmsABSTRACT
A neuromedina B (NB) e o peptídeo liberador de gastrina são peptídeos bombesina-símiles encontrados em mamíferos, inclusive em seres humanos. Ambos inibem a secreção hipofisária de tireotrofina (TSH); entretanto, somente a NB tem importância fisiológica demonstrada. A NB é produzida em abundância em tireotrofos e parece inibir a secreção de TSH por via autócrina, uma vez que o bloqueio do peptídeo endógeno causa aumento na liberação do TSH, tanto in vivo quanto in vitro. A NB é positivamente regulada pelos hormônios tireóideos (HT). Os HT aumentam o conteúdo de neuromedina B e do seu RNAm em adeno-hipófises de ratos hipotireóideos, poucas horas após sua administração, o que coincide com diminuição do TSH sérico. Isto nos levou a sugerir que a NB possa ser um intermediário protéico envolvido na inibição aguda da liberação de TSH induzida pelos HT. O TRH também altera rapidamente a expressão da NB. Quinze e 30 minutos após a administração do TRH em ratos normais já há diminuição do conteúdo hipofisário de NB e dos níveis do seu RNAm. No jejum e diabetes experimental, que se caracterizam por diminuição de HT séricos com níveis inadequadamente normais ou diminuídos de TSH, ocorre aumento do conteúdo de NB e de seu RNAm. O análogo de somatostatina, octreotide, também é capaz de aumentar o conteúdo de NB. Assim, a neuromedina B é um importante inibidor local da secreção de TSH, podendo ser uma via final comum de hormônios e neuro-hormônios que determinam variações na secreção de TSH.
Subject(s)
Humans , Animals , Bombesin/physiology , Gastrin-Releasing Peptide/physiology , Hypothalamo-Hypophyseal System/metabolism , Bombesin/analogs & derivatives , Tissue Distribution/physiology , Mammals , Receptors, Bombesin/physiology , Thyrotropin/antagonists & inhibitors , Thyrotropin/metabolismABSTRACT
Since GABA and its related enzymes had been determined in beta-cells of pancreas islets, effects of GABA on pancreatic exocrine secretion were investigated in the isolated perfused rat pancreas. GABA, given intra-arterially at concentrations of 3, 10, 30 and 100 microM, did not exert any influence on spontaneous or secretin (12 pM)-induced pancreatic exocrine secretion. However, GABA further elevated cholecystokinin (10 pM)-, gastrin-releasing peptide (100 pM)- or electrical field stimulation-induced pancreatic secretions of fluid and amylase, dose-dependently. The GABA-enhanced CCK-induced pancreatic secretions were completely blocked by bicuculline (10 microM), a GABAA receptor antagonist but not affected by saclofen (10 microM), a GABA(B) receptor antagonist. The enhancing effects of GABA (30 microM) on CCK-induced pancreatic secretions were not changed by tetrodotoxin (1 microM) but partially reduced by cyclo-(7-aminoheptanonyl-Phe-D-Trp-Lys-Thr[BZL]) (10 microM), a somatostatin antagonist. In conclusion, GABA enhances pancreatic exocrine secretion induced by secretagogues, which stimulate enzyme secretion predominantly, via GABA(A) receptors in the rat pancreas. The enhancing effect of GABA is partially mediated by inhibition of islet somatostatin release. GABA does not modify the activity of intrapancreatic neurons.
Subject(s)
Rats , Amylases/metabolism , Animals , Baclofen/pharmacology , Baclofen/analogs & derivatives , Bicuculline/pharmacology , Cholecystokinin/metabolism , Dose-Response Relationship, Drug , Electric Stimulation , gamma-Aminobutyric Acid/pharmacology , GABA Antagonists/pharmacology , Gastrin-Releasing Peptide/metabolism , Hormones/pharmacology , In Vitro Techniques , Pancreas/metabolism , Pancreas/enzymology , Pancreas/drug effects , Receptors, GABA-A/metabolism , Secretin/metabolism , Somatostatin/pharmacology , Tetrodotoxin/pharmacologyABSTRACT
The effect of substance P (SP) on thyrotropin (TSH) secretion is controversial. In this study we evaluated the effect of SP on TSH secretion by hemipituitaries of 3-month-old Wistar rats in vitro and its interaction with gastrin-releasing peptide (GRP) at equimolar concentrations (1 µM and 10 µM). TSH release was measured under basal conditions and 30 min after incubation in the absence or presence of SP, GRP or both peptides. Pituitary TSH content was also measured in the pituitary homogenate after incubation. SP at both concentrations caused a significant (P<0.05) increase in TSH secretion compared with all other groups, which was approximately 60 percent (1 µM) and 85 percent (10 µM) higher than that of the control group (23.3 + or - 3.0 ng/ml). GRP at the lower concentration did not produce a statistically significant change in TSH secretion, whereas at the concentration of 10 µM it produced a 50 percent reduction in TSH. GRP co-incubated with substance P completely blocked the stimulatory effect of SP at both concentrations. Pituitary TSH content decreased in the SP-treated group compared to controls (0.75 + or - 0.03 µg/hemipituitary) at the same proportion as the increase in TSH secretion, and this effect was also blocked when GRP and SP were co-incubated. In conclusion, in an in vitro system, SP increased TSH secretion acting directly at the pituitary level and this effect was blocked by GRP, suggesting that GRP is more potent than SP on TSH secretion, and that this inhibitory effect could be the predominant effect in vivo
Subject(s)
Rats , Animals , Gastrin-Releasing Peptide/physiology , In Vitro Techniques , Substance P/pharmacology , Thyrotropin/drug effects , Thyrotropin/metabolism , Analysis of Variance , Gastrin-Releasing Peptide/metabolism , Rats, Wistar , Receptors, Bombesin/metabolism , Substance P/metabolismABSTRACT
Although importance of intrapancreatic neurons containing gastrin-releasing peptide (GRP) in control of exocrine secretion has been raised, the nature of GRP in the pancreas is unclear Thus, the present study was undertaken to see distribution, content and molecular heterogeneity of immunoreactive GRP in the rat pancreas Content of immunoreactive GRP in the rat pancreas was 2 99 +/- 0.66 ng/g wet tissues determined by radioimmunoassay. Immunoreactive GRP was most abundantly expressed in the duodenal part among 3 parts of the pancreas, duodenal, body and splenic part. Vagotomy failed to change the content of immunoreactive GRP in the pancreas. Three distinct forms of immunoreactive GRP, very identical to GRP-27, bombesin-24 and neuromedin C, were observed in the rat pancreas by using reversed phase C18 HPLC and Sephadex G-50 superfine column chromatography. Cell bodies of neurons containing immunoreactive GRP were scattered in pancreatic connective tissues and their nerve fibers innerv ated pancreatic acini and large ducts as determined by immunohistochemistry. The present results suggest that three distinct forms of GRP exist in intrapancreatic GRPergic neurons, which exert a stimulatory role in pancreatic exocrine secretion in rats.
Subject(s)
Animals , Rats , Chromatography , Chromatography, High Pressure Liquid , Connective Tissue , Gastrin-Releasing Peptide , Immunohistochemistry , Nerve Fibers , Neurons , Pancreas , Population Characteristics , Radioimmunoassay , VagotomyABSTRACT
La secreción ácida gástrica es el resultado de la actividad habitual de las células oxínticas, activadas por un interjuego estimulador e inhibidor de factores que actúan por vía neurocrina, paracrina y endocrina. Hoy se sabe que los centros nerviosos superiores a través del vago, mantienen una influencia permanente sobre estas células y su secreción. El vago fúndico estimula colinérgicamente la célula parietal, y por otro lado, inhibe colinérgicamente la liberación antral de gastrina. El vago antral estimula a través de bombesina y/o péptido liberador de gastrina (PLG) la liberación de gastrina. Además, participa de un mecanismo inhibidor neuroendocrino de la secreción ácida o acción vagogastrona. La alimentación, aminoácidos en especial, provoca el mayor estímulo de la secreción de gastrina, que por vía endocrina sistémica o por vía endocrina portal, constituye el estímulo mas eficiente de la secreción ácida. La regulación o feed-back de la secreción ácida se efectiviza por agonistas y antagonistas neurocrinos, paracrinos o endocrinos, a través de un verdadero tandem integrado por somatostatina, VIP, secretina y GIP, entre otros.