Author(s): Yanagita T, Yamamoto R, Sugano T, Kobayashi H, Uezono Y,
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Abstract In isolated rat uterine strips, adrenomedullin (AM) inhibited the spontaneous periodic contraction in a concentration-dependent manner (IC(50)=22.3+/-0.7 nM). The inhibitory effect of AM was prevented by either AM(22-52), a putative antagonist for AM receptors, or calcitonin gene-related peptide (CGRP)(8-37), a putative antagonist for CGRP receptors. AM also attenuated bradykinin (BK)-induced periodic uterine contraction, which was blocked by AM(22-52) or CGRP(8-37), whereas AM had no effect on the periodic contraction caused by oxytocin or prostaglandin F(2alpha) (PGF(2alpha)). RT-PCR analysis showed that mRNAs for calcitonin receptor-like receptor (CRLR), receptor-activity-modifying protein (RAMP)1, RAMP2 and RAMP3 were expressed in the rat uterus. These results demonstrate that AM selectively inhibits spontaneous and BK-induced periodic contraction via activating receptors for AM and CGRP.
This article was published in Br J Pharmacol
and referenced in Journal of Autacoids and Hormones