Transcription, expression and tissue binding in vivo of INGAP and INGAP-related peptide in normal hamsters
| Autor: | María Inés Borelli, Luis Emilio Flores, Hector Herminio del Zotto, Antonio C. Boschero, Juan José Gagliardino, M. E. Garcia |
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| Rok vydání: | 2006 |
| Předmět: |
Male
Transcriptional Activation medicine.medical_specialty Physiology Clinical Biochemistry Hamster Pancreatitis-Associated Proteins Biology Biochemistry Cellular and Molecular Neuroscience Endocrinology In vivo Antigens Neoplasm Reference Values Internal medicine Cricetinae medicine Biomarkers Tumor Animals Lectins C-Type Tissue Distribution RNA Messenger Receptor Pancreas geography geography.geographical_feature_category Pancreatic islets Islet Immunohistochemistry Epithelium Small intestine Peptide Fragments medicine.anatomical_structure Gene Expression Regulation Organ Specificity Cytokines |
| Zdroj: | Regulatory peptides. 140(3) |
| ISSN: | 0167-0115 |
| Popis: | We studied islet neogenesis-associated protein (INGAP) transcription and its immunocytochemical presence in and binding in vivo of (125)I-tyrosylated INGAP pentadecapeptide ((125)I-T-INGAP-PP) to different normal male hamster tissues. (125)I-T-INGAP-PP was injected intraperitoneally with or without unlabeled T-INGAP-PP (0-1 mg/100 g bw), drawing blood samples at different times after injection; radioactivity was measured in serum, brain, skeletal muscle, dorsal root ganglia, liver, kidney, small intestine and pancreas samples, expressing results as organ:serum ratio. INGAP transcription (RT-PCR) and immunopositive cells were investigated in liver, kidney, brain, small intestine and pancreas. Total serum radioactivity increased progressively as a function of time; whereas 71% of this activity was displaced by unlabeled T-INGAP-PP at 5, 10 and 20 min, only 9% was at 60 min. Only liver, pancreas and small intestine specifically bound (125)I-T-INGAP-PP. The pancreas tissue dose-response curve showed a 50% displacement at 3.9x10(4) ng/100 g bw, suggesting a low binding affinity of its receptor. INGAP-mRNA was only identified in pancreatic islets and exocrine tissue. Our results suggest that INGAP transcription/expression is probably restricted to pancreas cells exerting its effect in a paracrine fashion. INGAP would be released and circulate bound to a serum protein from where it is bound and inactivated by the liver. Tissue binding could also explain INGAP's immunocytochemical presence in small intestine, where it could affect epithelial cell turnover. |
| Databáze: | OpenAIRE |
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