This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Naghashpour, M. Articles by Dahl, G. P. Search for Related Content PubMed PubMed Citation Articles by Naghashpour, M. Articles by Dahl, G. P. Pubmed/NCBI databases Gene GEO Profiles HomoloGene Protein UniGene Compound via MeSH Substance via MeSH Medline Plus Health Information Childbirth

Inhibitory Effect of Calcitonin Gene-Related Peptide on Myometrial Contractility Is Diminished at Parturition¹

Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136

Address all correspondence and requests for reprints to: G. Dahl, Department of Physiology and Biophysics (R-430), University of Miami School of Medicine, P.O. Box 016430, Miami, Florida 33101. E-mail: gdahl{at}mednet.med.miami.edu

The uterus is innervated by calcitonin gene-related peptide (CGRP) immunoreactive neurons, and CGRP inhibits spontaneous and evoked contractions in the uterus and fallopian tubes. In the present study using isometric force measurements on myometrial strips, we determined that CGRP inhibition of acetylcholine-induced contractions was drastically reduced at parturition compared with earlier stages of pregnancy in mice. The levels of inhibition exerted by CGRP paralleled the expression of a novel protein recently implicated in CGRP receptor activation, the CGRP-receptor component protein (CGRP-RCP). The mouse CGRP-RCP complementary DNA was isolated from uterus, and expression of the CGRP-RCP was monitored during gestation by Northern and Western blot analysis. Although CGRP-RCP messenger RNA levels did not vary significantly during gestation and postpartum, CGRP-RCP protein was greatly diminished at parturition. This diminution correlated with the loss of CGRP inhibition of acetylcholine-induced contractions observed in the force experiments. A role for CGRP and CGRP-RCP in modulation of myometrial smooth muscle contractility during pregnancy and in labor is suggested.

This article has been cited by other articles:

				M. Siaut, C. Zaros, E. Levivier, M.-L. Ferri, M. Court, M. Werner, I. Callebaut, P. Thuriaux, A. Sentenac, and C. Conesa An Rpb4/Rpb7-Like Complex in Yeast RNA Polymerase III Contains the Orthologue of Mammalian CGRP-RCP Mol. Cell. Biol., January 1, 2003; 23(1): 195 - 205. [Abstract] [Full Text]

				M. Naghashpour and G. Dahl Relaxation of Myometrium by Calcitonin Gene-Related Peptide Is Independent of Nitric Oxide Synthase Activity in Mouse Uterus Biol Reprod, November 1, 2000; 63(5): 1421 - 1427. [Abstract] [Full Text]

				M. I. Rosenblatt, G. P. Dahl, and I. M. Dickerson Characterization and Localization of the Rabbit Ocular Calcitonin Gene-Related Peptide (CGRP)-Receptor Component Protein (RCP) Invest. Ophthalmol. Vis. Sci., April 1, 2000; 41(5): 1159 - 1167. [Abstract] [Full Text]

				M. Naghashpour and G. Dahl Sensitivity of myometrium to CGRP varies during mouse estrous cycle and in response to progesterone Am J Physiol Cell Physiol, March 1, 2000; 278(3): C561 - C569. [Abstract] [Full Text] [PDF]

				M.-L. Ferri, G. Peyroche, M. Siaut, O. Lefebvre, C. Carles, C. Conesa, and A. Sentenac A Novel Subunit of Yeast RNA Polymerase III Interacts with the TFIIB-Related Domain of TFIIIB70 Mol. Cell. Biol., January 15, 2000; 20(2): 488 - 495. [Abstract] [Full Text]

				W. Balkan, E. L. Oates, G. A. Howard, and B. A. Roos Testes Exhibit Elevated Expression of Calcitonin Gene-Related Peptide Receptor Component Protein Endocrinology, March 1, 1999; 140(3): 1459 - 1469. [Abstract] [Full Text]

				B. N. Evans, M. I. Rosenblatt, L. O. Mnayer, K. R. Oliver, and I. M. Dickerson CGRP-RCP, a Novel Protein Required for Signal Transduction at Calcitonin Gene-related Peptide and Adrenomedullin Receptors J. Biol. Chem., September 29, 2000; 275(40): 31438 - 31443. [Abstract] [Full Text] [PDF]