The relaxing effects of angiotensin II and angiotensin III on canine isolated contracted tracheal muscle
Ercan, Z.S.; Ersoy, F.F.; Türker, R.K.; Bor, N.
Journal of Pharmacy and Pharmacology 30(7): 452-453
1978
ISSN/ISBN: 0022-3573 PMID: 27615 Document Number: 136562
Angiotensin I and angiotensin II (A II) have equal relaxing activities on the cat isolated tracheal muscle contracted by 5-HT [5-hydroxytryptamine]. Acetylsalicylic acid (ASA), a potent prostaglandin (PG) synthetase inhibitor, reduces the relaxing effects of both peptides but not as effectively as it inhibits bradykinin. It is highly possible that the relaxing effects of angiotensin peptides are mediated through the release of PG from the tissue. A III and A II were found to induce a relaxation on the dog isolated tracheal muscle contracted by acetylcholine. It therefore seemed of interest to investigate whether PG production was involved in this relaxant effect of the peptides by the potent PG synthetase inhibitor, ASA. An attempt was also made to compare the relaxing potencies of A II and A III on the canine isolated contracted tracheal muscle. It may be that the relaxing effects of A II and A III on the contracted canine tracheal muscle are mediated through the release of PG from the tissue. Secondly A III appears to have higher agonistic activity in the trachea than A II.