Biomaterial Database

Detection of the 5-HT1A receptor and 5-HT1A receptor mRNA in the rat bowel and pancreas: comparison with 5-HT1P receptors. 1993

A L Kirchgessner, and M T Liu, and M J Howard, and M D Gershon

Department of Anatomy and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York 10032.

We tested the hypothesis that the rat bowel and pancreas contain 5-HT1A receptors. 3H-8-hydroxy-2-(di-n-propylamino)tetralin (3H-8-OH-DPAT) was used as a radioligand. Binding of 3H-8-OH-DPAT to membranes derived from the myenteric plexus and the pancreas was investigated by rapid filtration. Alternatively, radioautography was employed to locate 3H-8-OH-DPAT binding sites in frozen sections of unfixed bowel or pancreas. An excess of 5-HT (10 microM) was used to define nonspecific binding. Saturable, high affinity binding of 3H-8-OH-DPAT to enteric (Kd = 2.8 +/- 1.1 nM; Bmax = 83.8 +/- 4.3 fmol/mg protein) and pancreatic (Kd = 6.6 +/- 1.3 nM; Bmax = 44 +/- 2.2 fmol/mg protein) membranes was found. The binding of 3H-8-OH-DPAT to enteric and pancreatic membranes was inhibited by 8-OH-DPAT, NAN-190, and spiperone. In contrast, the binding of 3H-8-OH-DPAT to enteric and pancreatic membranes was not inhibited by 5-carboxyamidotryptamine, or by a variety of compounds known to bind to other subtypes of 5-HT receptor. Digoxigenin-labeled oligonucleotides were found to detect mRNA encoding the 5-HT1A receptor in a subset of neurons in myenteric and submucosal ganglia. In contrast, 5-HT1A mRNA was not found in the pancreas. Radioautography revealed that the highest density of 3H-8-OH-DPAT binding sites was found in the stomach. These sites were especially numerous in the lamina propria adjacent to gastric glands, and in myenteric ganglia. Pancreatic 5-HT1A receptors were located on nerves, lymphoid tissue (especially the capsule of nodes), and on cells scattered in the pancreatic parenchyma. The concentration of 3H-8-OH-DPAT binding sites in the rat bowel and pancreas was less than that of 3H-5-HT binding sites; however, the distribution of 3H-8-OH-DPAT binding sites was similar to that of sites that bind 3H-5-HT. It is concluded that the rat gut and its extension in the pancreas contains 5-HT1A receptors. Many, if not all, of the nerve cells and processes that express 5-HT1A receptors express 5-HT1P receptors as well. The function of these receptors in the physiology of the entero-pancreatic innervation remains to be determined.

UI	MeSH Term	Description	Entries
D007413	Intestinal Mucosa	Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.	Intestinal Epithelium,Intestinal Glands,Epithelium, Intestinal,Gland, Intestinal,Glands, Intestinal,Intestinal Gland,Mucosa, Intestinal
D008297	Male		Males
D008566	Membranes	Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.	Membrane Tissue,Membrane,Membrane Tissues,Tissue, Membrane,Tissues, Membrane
D010179	Pancreas	A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.
D011985	Receptors, Serotonin	Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.	5-HT Receptor,5-HT Receptors,5-Hydroxytryptamine Receptor,5-Hydroxytryptamine Receptors,Receptors, Tryptamine,Serotonin Receptor,Serotonin Receptors,Tryptamine Receptor,Tryptamine Receptors,Receptors, 5-HT,Receptors, 5-Hydroxytryptamine,5 HT Receptor,5 HT Receptors,5 Hydroxytryptamine Receptor,5 Hydroxytryptamine Receptors,Receptor, 5-HT,Receptor, 5-Hydroxytryptamine,Receptor, Serotonin,Receptor, Tryptamine,Receptors, 5 HT,Receptors, 5 Hydroxytryptamine
D005260	Female		Females
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001345	Autoradiography	The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)	Radioautography
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining