Effect of inhibitors of enkephalin degradation in the isolated guinea-pig ileum |
| |
Authors: | J G van Amsterdam K J van Buuren M J Krielaart O P Zuiderveld R P Tijms |
| |
Institution: | Department of Pharmacy, University of Amsterdam, The Netherlands. |
| |
Abstract: | Bestatin and high concentration of puromycin increase the depressing effect of Met] enkephalin on the twitch response of the electrically stimulated guinea-pig ileum. Thiorphan (enkephalinase A inhibitor) is hardly effective, but phelorphan (mercapto-acetyl-Phe-Phe) a newly synthesized enzyme-inhibitor which effectively inhibits the enkephalinase A, enkephalinase B and soluble aminopeptidase activity, potentiates the effect of enkephalin dose-dependently and in low concentrations (0.01-1 microM). Enkephalinase A, though present in these tissues, is not functional under the conditions of the test, because it is inhibited by the physiological buffer itself. These results demonstrate that enkephalinase B and the membrane bound aminopeptidase, but not the soluble aminopeptidase or enkephalinase A hydrolyse enkephalins in the isolated guinea-pig ileum. |
| |
Keywords: | |
|
|