Pancreatic Polypeptide: Identification of Target Tissues Using an In Vivo Radioreceptor Assay
| Autor: | M.A Shetzline, William B. Zipf, M.T Nishikawara |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Male
Duodenum Physiology Biology Pancreatic Polypeptide Binding Competitive Biochemistry Receptors Gastrointestinal Hormone Rats Sprague-Dawley Radioligand Assay Cellular and Molecular Neuroscience Endocrinology Interstitial fluid In vivo Adrenal Glands Intestine Small Extracellular fluid medicine Animals Insulin Pancreatic polypeptide Neuropeptide Y Tissue Distribution Plasma Volume Receptor Pancreas Common Bile Duct Binding Sites Neuropeptide Y receptor Rats medicine.anatomical_structure Cattle Extracellular Space |
| Zdroj: | Peptides. 19:279-289 |
| ISSN: | 0196-9781 |
| Popis: | The definitive function of pancreatic polypeptide in mammalian physiology remains unknown. The identification of specific PP target tissues should be helpful to further investigations into the possible regulatory actions of this peptide. An in vivo radioreceptor assay was used in the rat to locate potential binding sites of I(125) bovine PP. In vitro, high concentrations of unlabeled hormone competitively inhibit binding to receptors by low concentrations of labeled hormone. In vivo studies showed that, in the presence of concentrated unlabeled pancreatic polypeptide, labeled PP distributes between the plasma and interstitial fluid. When excess unlabeled PP is replaced with saline in the companion animals, the labeled peptide appears to distribute in a volume that exceeds the combined plasma volume and interstitial fluid volume of the tissue. Using this in vivo receptor assay, the distribution volume that exceeds the anatomic extracellular volume has been identified as the receptor compartment. With this assay we demonstrated in the rat specific and displaceable PP binding to the ductus choledochus, duodenum, ileum, and adrenal gland. The NVV determined in the adrenal gland of experimental animals was 3.9 times greater than that found in the control group. Binding was rapid and was displaced only by excess unlabeled pancreatic polypeptide. Neither excess insulin nor excess neuropeptide Y significantly reduced this binding. |
| Databáze: | OpenAIRE |
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