Abstract
ATP causes relaxation of various smooth muscle containing preparations. ATP and related analogs were applied to strips of trachea and taenia coli from guinea-pigs in organ baths for 60 sec. The formation of adenosine was signalled by potentiation of relaxations in the presence of the adenosine transport inhibitor dipyridamole. The basis for this potentiation is that adenosine which is also a potent relaxant is rapidly taken up into muscle cells decreasing its effect. ATP caused relaxations of both taenia coli and tracheal strips and both responses were potentiated by dipyridamole signifying that adenosine was being formed during the contact times. In the taenia both the α,β and the β,γ-methylene isosteres of ATP caused relaxations. Dipyridamole potentiated responses to the latter, but failed to affect responses to the former. Since methylene subtitution renders the analog stable at that site it is presumed that the β,γ-methylene isostere rapidly formed adenosine due to the action of a pyrophosphohydrolase. In tracheal strips the β,γ-methylene isostere of ATP caused relaxations which were potentiated by dipyridamole, the α,β-methylene isostere was inactive either in the presence or absence of dipyridamole. This suggested that in contrast to the taenia, ATP is inactive in the trachea per se and must first be degraded to adenosine which in turn causes the relaxation.
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Satchell, D. INFERENCES ON THE RAPID METABOLISM OF EXOGENOUSLY APPLIED.ATP IN ISOLATED SMOOTH MUSCLE PREPARATIONS USING PHARMACOLOGICAL STUDIES: 179. Pediatr Res 19, 773 (1985). https://doi.org/10.1203/00006450-198507000-00199
Issue date:
DOI: https://doi.org/10.1203/00006450-198507000-00199
