Inverse regulation of α- and β-adrenoceptors during trinitrobenzenesulfonic acid (TNB)-induced inflammation in guinea-pig small intestine
| Autor: | R. Garcia-Villar, J. P. Martinolle, N. Dubech, Jean More |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Male
medicine.medical_specialty Guinea Pigs Rauwolscine Inflammation Biology Tritium General Biochemistry Genetics and Molecular Biology Guinea pig chemistry.chemical_compound Internal medicine Intestine Small Receptors Adrenergic beta medicine Prazosin Animals Intestinal Mucosa General Pharmacology Toxicology and Pharmaceutics Receptor Denervation Membranes Yohimbine General Medicine Receptors Adrenergic alpha Enteritis Small intestine Dissociation constant Disease Models Animal Kinetics medicine.anatomical_structure Endocrinology Trinitrobenzenesulfonic Acid chemistry Dihydroalprenolol medicine.symptom medicine.drug |
| Zdroj: | Life Sciences. 52:1499-1508 |
| ISSN: | 0024-3205 |
| DOI: | 10.1016/0024-3205(93)90112-g |
| Popis: | The hypothesis has been raised that intestinal motor disturbances induced by inflammation of the digestive tract may reflect alterations in intestinal cell-membrane receptors. This question has been addressed herein for adrenoceptors by performing [3H]prazosin, [3H]rauwolscine and [3H]DHA binding studies on guinea-pig jejunal smooth-muscle membrane preparations from both healthy controls and 3, 6, and 10 days after TNB-induced intestinal inflammation. Each of the adrenoceptor subtype-selective radioligands used bound selectively to a single saturable class of sites, with no significant (p0.05) variation of dissociation constant (KD) values along the inflammatory process. In contrast maximal binding capacities (Bmax) for the different radioligands varied moderately but significantly (p0.05 and p0.01) according to the time after TNB injection. The alpha-adrenoceptors were significantly upregulated, respectively from (mean +/- SE in fmoles/mg of proteins) 27 +/- 3.8 (controls) to 91 +/- 3.1 (day 10) for the alpha 1-subtype, and from 26 +/- 2.7 (controls) to 102 +/- 5.9 (day 10) for the alpha 2-subtype. In contrast beta-adrenoceptors were down-regulated from 384 +/- 34.6 (controls) to 158 +/- 17.2 (day 10). These findings highlighted an apparently inverse pathological regulation of intestinal alpha- and beta- adrenoceptor densities. They suggest that changes in intestinal adrenoceptors, probably resulting from functional denervation of the inflamed bowel tissue, may contribute to the altered intestinal motility observed in inflammatory bowel diseases. |
| Databáze: | OpenAIRE |
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