Gastric inhibitory polypeptide (GIP) binding sites in rat brain
| Autor: | Steven R. Vigna, Andrew M. Kaplan |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Physiology Vasoactive intestinal peptide Gastric Inhibitory Polypeptide Biology Binding Competitive Biochemistry Glucagon Receptors Gastrointestinal Hormone Secretin Rats Sprague-Dawley Cellular and Molecular Neuroscience Endocrinology Gastric inhibitory polypeptide Internal medicine medicine Animals Tissue Distribution Binding site Receptor Brain Chemistry Neuropeptides Brain Rats Dissociation constant Gastrointestinal hormone Autoradiography hormones hormone substitutes and hormone antagonists |
| Zdroj: | Peptides. 15:297-302 |
| ISSN: | 0196-9781 |
| DOI: | 10.1016/0196-9781(94)90016-7 |
| Popis: | Synthetic porcine gastric inhibitory polypeptide (GIP) was iodinated and purified by reverse-phase HPLC and used to localize saturable [125I]GIP binding sites by radioligand binding to frozen sections of rat brain followed by autoradiography. Saturable [125I]GIP binding sites were expressed in several brain regions including cerebral cortex, anterior olfactory nucleus, lateral septal nucleus, subiculum, inferior colliculus, and inferior olive. Saturable [125I]GIP binding was time dependent, reversible, high affinity, and specific for GIP. Scatchard analysis of equilibrium binding resulted in an estimated dissociation constant (Kd) of 16-62 pM for the rat brain [125I]GIP binding sites. Peptides with amino acid sequences similar to GIP such as secretin, vasoactive intestinal polypeptide (VIP), glucagon, and peptide histidine isoleucine (PHI) only partially inhibited saturable [125I]GIP binding at concentrations approximately 10,000-100,000-fold higher than GIP. Saturable [125I]GIP binding was not observed in other rat organs surveyed such as spinal cord, pituitary, stomach, small intestine, colon, pancreas, liver, heart, or skeletal muscle. We conclude that a saturable [125I]GIP binding site with the pharmacological properties of an authentic GIP receptor is expressed in certain regions of the rat brain. |
| Databáze: | OpenAIRE |
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