Intermedin Is a Calcitonin/Calcitonin Gene-related Peptide Family Peptide Acting through the Calcitonin Receptor-like Receptor/Receptor Activity-modifying Protein Receptor Complexes

Abstract

Calcitonin, calcitonin gene-related peptide (CGRP), adrenomedullin (ADM), and amylin belong to a unique group of peptide hormones important for homeostasis in diverse tissues. Calcitonin is essential for calcium balance, whereas CGRP and ADM are important for neurotransmission and cardiovascular and respiratory regulation. Based on phylogenetic analysis, we identified intermedin as a novel member of the calcitonin/CGRP peptide family. Analysis of intermedin expression indicated that intermedin is expressed primarily in the pituitary and gastrointestinal tract. Intermedin increased cAMP production in SK-N-MC and L6 cells expressing endogenous CGRP receptors and competed with labeled CGRP for binding to its receptors in these cells. In addition, treatment of 293T cells expressing recombinant calcitonin receptor-like receptor (CRLR) and one of the three receptor activity-modifying proteins (RAMPs) showed that a CRLR/RAMP receptor complex is required for intermedin signaling. In contrast to CGRP and ADM, which exhibited a preferential stimulation of CRLR when co-expressed with RAMP1 and RAMP2 or RAMP3, respectively, intermedin represents a nonselective agonist for the RAMP coreceptors. In vivo studies demonstrated that intermedin treatment led to blood pressure reduction in both normal and spontaneously hypertensive rats via interactions with the CRLR/RAMP receptor complexes. Furthermore, in vivo treatment in mice with intermedin led to suppression of gastric emptying activity and food intake. Thus, identification of intermedin as a novel member of the calcitonin/CGRP peptide family capable of signaling through CRLR/RAMP receptor complexes provides an additional player in the regulation of peripheral tissues by CRLR and will allow development of new therapeutic agents for pathologies associated with diverse vascular and gastrointestinal disorders. Calcitonin, calcitonin gene-related peptide (CGRP), adrenomedullin (ADM), and amylin belong to a unique group of peptide hormones important for homeostasis in diverse tissues. Calcitonin is essential for calcium balance, whereas CGRP and ADM are important for neurotransmission and cardiovascular and respiratory regulation. Based on phylogenetic analysis, we identified intermedin as a novel member of the calcitonin/CGRP peptide family. Analysis of intermedin expression indicated that intermedin is expressed primarily in the pituitary and gastrointestinal tract. Intermedin increased cAMP production in SK-N-MC and L6 cells expressing endogenous CGRP receptors and competed with labeled CGRP for binding to its receptors in these cells. In addition, treatment of 293T cells expressing recombinant calcitonin receptor-like receptor (CRLR) and one of the three receptor activity-modifying proteins (RAMPs) showed that a CRLR/RAMP receptor complex is required for intermedin signaling. In contrast to CGRP and ADM, which exhibited a preferential stimulation of CRLR when co-expressed with RAMP1 and RAMP2 or RAMP3, respectively, intermedin represents a nonselective agonist for the RAMP coreceptors. In vivo studies demonstrated that intermedin treatment led to blood pressure reduction in both normal and spontaneously hypertensive rats via interactions with the CRLR/RAMP receptor complexes. Furthermore, in vivo treatment in mice with intermedin led to suppression of gastric emptying activity and food intake. Thus, identification of intermedin as a novel member of the calcitonin/CGRP peptide family capable of signaling through CRLR/RAMP receptor complexes provides an additional player in the regulation of peripheral tissues by CRLR and will allow development of new therapeutic agents for pathologies associated with diverse vascular and gastrointestinal disorders. Originally isolated as a polypeptide hormone essential for calcium balance (1Hargis G.K. Williams G.A. Tenenhouse A. Arnaud C.D. Science. 1966; 152: 73-75Crossref PubMed Scopus (16) Google Scholar, 2Copp D.H. Clin. Investig. Med. 1994; 17: 268-277PubMed Google Scholar), calcitonin belongs to a group of peptide hormones including α-CGRP, 1The abbreviations used are: CGRP, calcitonin gene-related peptide; ADM, adrenomedullin; GPCR, G protein-coupled receptor; CRLR, calcitonin receptor-like receptor; RAMP, receptor activity-modifying protein; SHRs, spontaneously hypertensive rats; IMD, intermedin; IMDL, intermedin-long; IMDS, intermedin-short; SRP, stresscopin-related peptide; MSH, melanin-stimulating hormone. β-CGRP, adrenomedullin (ADM), and amylin (3Amara S.G. Jonas V. Rosenfeld M.G. Ong E.S. Evans R.M. Nature. 1982; 298: 240-244Crossref PubMed Scopus (1754) Google Scholar). Among these tissue-specific peptides, ADM and CGRP are important endocrine and neurocrine integrators of homeostasis in the vascular and respiratory systems, whereas amylin is essential for optimal glucose metabolism. The biological actions of these peptides are mediated via binding to two closely related type II G protein-coupled receptors (GPCRs), the calcitonin receptor, and the calcitonin receptor-like receptor (CRLR) (4Christopoulos G. Perry K.J. Morfis M. Tilakaratne N. Gao Y. Fraser N.J. Main M.J. Foord S.M. Sexton P.M. Mol. Pharmacol. 1999; 56: 235-242Crossref PubMed Scopus (421) Google Scholar, 5Poyner D.R. Sexton P.M. Marshall I. Smith D.M. Quirion R. Born W. Muff R. Fischer J.A. Foord S.M. Pharmacol. Rev. 2002; 54: 233-246Crossref PubMed Scopus (693) Google Scholar). Although the calcitonin receptor is the main mediator for calcitonin action, it also binds amylin. Recent cloning and functional studies have shown that CGRP, ADM, and, to a lesser extent, amylin interact with different combinations of CRLR and the three receptor activity-modifying proteins (RAMPs) (5Poyner D.R. Sexton P.M. Marshall I. Smith D.M. Quirion R. Born W. Muff R. Fischer J.A. Foord S.M. Pharmacol. Rev. 2002; 54: 233-246Crossref PubMed Scopus (693) Google Scholar, 6McLatchie L.M. Fraser N.J. Main M.J. Wise A. Brown J. Thompson N. Solari R. Lee M.G. Foord S.M. Nature. 1998; 393: 333-339Crossref PubMed Scopus (1868) Google Scholar). Studies using mutant mice deficient in α-CGRP, ADM, or amylin have indicated that CRLR could be important for cardiovascular morphogenesis, sensory neurotransmission, inflammatory reactions, nociceptive behavior, and glucose homeostasis (7Hay D.L. Smith D.M. Trends Pharmacol. Sci. 2001; 22: 57-59Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar, 8Shindo T. Kurihara Y. Nishimatsu H. Moriyama N. Kakoki M. Wang Y. Imai Y. Ebihara A. Kuwaki T. Ju K.H. Minamino N. Kangawa K. Ishikawa T. Fukuda M. Akimoto Y. Kawakami H. Imai T. Morita H. Yazaki Y. Nagai R. Hirata Y. Kurihara H. Circulation. 2001; 104: 1964-1971Crossref PubMed Scopus (260) Google Scholar, 9Zhang L. Hoff A.O. Wimalawansa S.J. Cote G.J. Gagel R.F. Westlund K.N. Pain. 2001; 89: 265-273Abstract Full Text Full Text PDF PubMed Scopus (135) Google Scholar, 10Salmon A.M. Damaj I. Sekine S. Picciotto M.R. Marubio L. Changeux J.P. Neuroreport. 1999; 10: 849-854Crossref PubMed Scopus (52) Google Scholar, 11Salmon A.M. Damaj M.I. Marubio L.M. Epping-Jordan M.P. Merlo-Pich E. Changeux J.P. Nat. Neurosci. 2001; 4: 357-358Crossref PubMed Scopus (94) Google Scholar, 12Mulder H. Gebre-Medhin S. Betsholtz C. Sundler F. Ahren B. Am. J. Physiol. 2000; 278: E684-E691Google Scholar). Thus, the physiological functions of the peptides in this family are determined by receptor-binding specificity and the tissue expression profiles of individual ligands. Because the expression of CGRP and its binding sites does not overlap in the brain (13Kruger L. Mantyh P.W. Sternini C. Brecha N.C. Mantyh C.R. Brain Res. 1988; 463: 223-244Crossref PubMed Scopus (191) Google Scholar), we hypothesized the existence of additional calcitonin/CGRP family peptides. Using a phylogenetic profiling approach to analyze the GenBank™/EBI Data Bank, we identified a novel calcitonin/CGRP family peptide, intermedin, from the genomes of human and other vertebrates. Sequence analysis of the prepropolypeptides of different family genes indicated that the sequence homology between intermedin and the paralogous peptides is restricted to the mature peptide and that the intermedin gene evolved during early vertebrate evolution. Pharmacological analyses showed that intermedin signals through CRLR/RAMP receptor complexes and activates the cAMP-dependent pathway in transfected cells. We show that intermedin signals through the CRLR signaling system to regulate vascular and gastrointestinal functions in vivo. Cloning, Phylogenetic Analysis, and Expression Profiles of Human Intermedin—Human intermedin identified from an expressed sequence and a sequence and in and its by using a human pituitary analysis of intermedin in the human from The intermedin peptides from on a expressed sequence sequence and The and intermedin on expressed sequence and α-CGRP, β-CGRP, ADM, and amylin on and The used to the mature peptides from different Phylogenetic analysis using a in The of calcitonin/CGRP family peptides using the Sequence Analysis analysis of intermedin pituitary from pituitary from using on and with a intermedin The for with peptides on the and by pressure with a and by using a ADM, β-CGRP, and related peptides from and from of different hormones in and in using peptides to of human intermedin peptide on the sequence in this of human and and the to other family peptides. The intermedin peptide to using using In analysis, the intermedin with intermedin from different not with paralogous peptides, including CGRP, ADM, and amylin. analysis, tissues from and and as Mol. 1999; PubMed Google Scholar). that the intermedin the intermedin mature peptide, human intermedin the expression analysis of intermedin in 293T cells transfected with the intermedin expression using the calcium the and using a the for in with and analysis using of cAMP in SK-N-MC and L6 by Intermedin and SK-N-MC cells and L6 cells expressing endogenous CRLR from SK-N-MC and L6 cells in in a in cells with for in and to of cAMP by cells and cAMP determined by a Nat. Med. 2001; PubMed Scopus Google Scholar). of CRLR/RAMP by Intermedin in 293T the between intermedin and the CRLR/RAMP receptor we human CRLR, and and by from human using two of the of by and the expression allow the of expression of these CRLR and the of the mature with a Because it shown that the RAMP1 signaling K. Y. M. K. T. M. K. T. T. J. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar), we used the RAMP1 for analysis of intermedin signaling. cells in in with and The cells with of CRLR of RAMP expression using the calcium cells with from and for the of expression of CRLR and RAMP on the the cells with in and for in with of for The to the and for with of by of activity in using and a binding determined by of the peptide a of the of in transfected cells in tissue and for in the of treatment for binding in for SK-N-MC and L6 cells in binding and with of and of peptides. a the Nat. Med. 2001; PubMed Scopus Google Scholar). determined using a of Intermedin on and in and pressure in rats and spontaneously hypertensive rats of to the pressure determined by a blood pressure system using the of the pressure rats for that a rats with of pressure and for in blood pressure as the of of Intermedin on mice of food for food for with different hormones or mice of food and The the and emptying by the of mice with the of mice the of hormone Analysis of mice in a with mice of food for with to by in the and and between treatment by analysis of and Intermedin as a the GenBank™/EBI Data for sequence with unique and by calcitonin/CGRP family peptides using a phylogenetic profiling approach that used to novel hormone family peptides Nat. Med. 2001; PubMed Scopus Google Scholar). for the of sites the mature of the Based on these we identified intermedin genes from and including and a Human intermedin a of with a peptide for the Although the sequence of intermedin to a of the is by sites the and an the The mature of intermedin sequence with ADM and with CGRP the mature an an by a that is by calcitonin/CGRP family peptides Furthermore, sequence of intermedin from and indicated that sequence in is restricted to the mature The mature of human and whereas human and are In addition, the and intermedin peptides to by one Furthermore, analysis of indicated that the of sites by a different whereas an of the of human intermedin is in that the mature intermedin from human and other could be a the of these sequence we that a mature peptide and a intermedin could be by the by an Because the of intermedin from diverse is not intermedin is to additional peptides as the peptide in the ADM H. K. Y. Y. Kangawa K. H. T. Res. 1994; PubMed Scopus Google Scholar). Phylogenetic analysis of CGRP family peptides from and an for three of these peptide with and in a with ADM and CGRP Thus, intermedin and other family peptides evolved the of and analysis showed that intermedin is on the of human and In both human and intermedin an In other calcitonin/CGRP family genes on human and Intermedin the cAMP-dependent in SK-N-MC and L6 via the CGRP sequence and phylogenetic on indicated that intermedin is to ADM and CGRP, whereas a with CRLR, the receptor for ADM and Thus, CRLR is a receptor for this we human SK-N-MC cells and L6 to different of CRLR and T. D.L. S. D.R. S. Smith D.M. J. Pharmacol. 2002; PubMed Scopus Google Scholar), with intermedin peptides and cAMP shown in and treatment with the or peptide in in cAMP production in both The is as treatment with a of intermedin, a intermedin or a peptide from the of human intermedin in not that and of intermedin are important for intermedin with (5Poyner D.R. Sexton P.M. Marshall I. Smith D.M. Quirion R. Born W. Muff R. Fischer J.A. Foord S.M. Pharmacol. Rev. 2002; 54: 233-246Crossref PubMed Scopus (693) Google Scholar, T. D.L. S. D.R. S. Smith D.M. J. Pharmacol. 2002; PubMed Scopus Google Scholar, D.R. Brown C. M.R. J. Pharmacol. PubMed Scopus Google Scholar), both ADM and also cAMP production in these and the of intermedin by with a CGRP receptor in L6 cells that intermedin activates the cAMP-dependent pathway via the CGRP receptor T. A. T. A. T. T. M. T. T. Am. J. Physiol. Google Scholar). the of intermedin on cAMP L6 cells with a intermedin receptor-binding or an shown in to be a functional of intermedin action, with the of T. A. T. A. T. T. M. T. T. Am. J. Physiol. Google Scholar). In addition, with the the of intermedin, whereas with an the stresscopin-related peptide II a between intermedin and CRLR, we used CGRP as the for receptor binding shown in and and binding to the SK-N-MC and L6 cells Intermedin a for CRLR/RAMP and adrenomedullin through the CRLR/RAMP of CRLR and one of the three RAMP the of CRLR/RAMP receptor complexes in intermedin we 293T cells expressing different combinations of recombinant CRLR with intermedin and related peptides. shown in treatment of intermedin, CGRP, or ADM on cAMP production in 293T cells expressing CRLR whereas calcitonin increased cAMP production via the endogenous calcitonin In intermedin cAMP production in cells expressing different CRLR/RAMP receptor complexes with CGRP and ADM exhibited a preferential stimulation of CRLR when co-expressed with RAMP1 and RAMP2 or RAMP3, with CGRP, intermedin exhibited a in the stimulation of cAMP production in cells expressing activity with In intermedin a in the of both and with Thus, the of for the stimulation of and is CGRP ADM, ADM CGRP, and ADM CGRP, Furthermore, with the expression of CRLR/RAMP receptor complexes on the of transfected cells to be increased by CRLR and Intermedin Expression in the and analysis showed that the intermedin is expressed in the pituitary and analysis of pituitary showed that two intermedin of and in the pituitary the expression of intermedin, using a intermedin peptide shown in the is for intermedin and showed with related peptides, including CGRP, ADM, and amylin. Using the analysis of different tissues intermedin expression in the pituitary and shown in and intermedin expressed in the of the with signals in the In using or with the intermedin showed signals and analysis of pituitary from rats and showed that intermedin expression restricted to the and of the pituitary G and Because melanin-stimulating hormone a expression in the pituitary we the with the shown in the of intermedin in the pituitary not by with an that the intermedin the mature intermedin peptide, a human intermedin in the expression and the expression of intermedin peptide from this using transfected 293T cells. analysis of showed that cells transfected with the intermedin expression an mature intermedin peptide the whereas the from cells transfected with the the expression of intermedin in the gastrointestinal a of human from the gastrointestinal by shown in of the expression of the intermedin could be in the and analysis using a of showed that the expression of the intermedin in the and Furthermore, showed that intermedin primarily in the of the and that the by with the intermedin of the related ADM is one of the (5Poyner D.R. Sexton P.M. Marshall I. Smith D.M. Quirion R. Born W. Muff R. Fischer J.A. Foord S.M. Pharmacol. Rev. 2002; 54: 233-246Crossref PubMed Scopus (693) Google and the intermedin could be the to on diverse peripheral we the of intermedin on blood pressure regulation in normal rats and using a shown in of or blood pressure in normal to that by In addition, treatment of or also increased as for ADM In of the or the peptide not on blood pressure regulation. Because intermedin signals through CRLR/RAMP receptor the of a CGRP receptor to the actions of intermedin also shown in treatment with a of the of with the intermedin receptor-binding the of In addition, we the of intermedin in treatment blood pressure in to the in normal and the of by with In with the a S. Hirata Y. H. K. T. K. S. F. 1994; PubMed Scopus Google Scholar). Thus, intermedin is a for the vascular CRLR/RAMP signaling system and could be important in the of vascular for Intermedin and studies have shown that both CGRP and ADM have L. Am. J. Physiol. 2002; PubMed Scopus Google and could actions through or peripheral CRLR/RAMP intermedin a in we the of intermedin to regulate on food in with IMDL, IMDS, ADM, or a type II hormone agonist food in mice Nat. Med. 2001; PubMed Scopus Google Scholar, K. J. J. J. Sci. S. A. 2001; PubMed Scopus Google Scholar). Because intermedin is expressed in the of the it could have a in gastrointestinal We the of intermedin to regulate gastric emptying activity in shown in of intermedin gastric emptying to treatment with a gastric emptying suppression peptide, II Nat. Med. 2001; PubMed Scopus Google Scholar, K. J. J. J. Sci. S. A. 2001; PubMed Scopus Google Scholar). treatment with ADM also gastric emptying with a Thus, intermedin could through the regulation of gastrointestinal L. Am. J. Physiol. 2002; PubMed Scopus Google Scholar, N. Y. Sci. PubMed Scopus Google of gastric emptying activity by is the reduction of gastric emptying by ADM and II hormone treatment with emptying by the of mice with the of mice hormone treatment and the of hormone with and the as used as different from with We have used a approach to novel polypeptide and receptors on the of Mol. 1999; PubMed Google Scholar, Nat. Med. 2001; PubMed Scopus Google Scholar, K. S. J. M. Science. 2002; PubMed Scopus Google Scholar, K. A. Mol. 2002; PubMed Google Scholar). Based on the analysis of the of calcitonin/CGRP family from diverse we have identified a novel family peptide that is expressed in the pituitary and tract. Studies using 293T cells expressing recombinant CRLR and demonstrated that intermedin is a peptide and activates of the G family through CRLR/RAMP receptor complexes. In contrast to CGRP and ADM, which exhibited a preferential stimulation of CRLR when co-expressed with RAMP1 and RAMP2 or RAMP3, respectively, intermedin represents a nonselective agonist for the three CRLR/RAMP receptor complexes. the of calcitonin in the the calcitonin/CGRP family peptides have a of gene and functional this group of peptide hormones on diverse with two closely related and three unique that receptors to the a complex signaling system in diverse (5Poyner D.R. Sexton P.M. Marshall I. Smith D.M. Quirion R. Born W. Muff R. Fischer J.A. Foord S.M. Pharmacol. Rev. 2002; 54: 233-246Crossref PubMed Scopus (693) Google Scholar). Calcitonin, CGRP, ADM, and amylin are expressed in a tissue-specific with the expression in the and Although it that the signaling by CGRP, ADM, and amylin is unique peptide hormones and the of a the of these peptides and receptors in different to be The of intermedin as a calcitonin/CGRP family peptide expressed in the pituitary and provides a new for peripheral regulation mediated by the CRLR/RAMP a in the of CRLR/RAMP receptor complexes in intermedin we the of CRLR/RAMP receptor complexes in transfected 293T cells and demonstrated that RAMP is required for intermedin through intermedin exhibited a receptor from that of CGRP or ADM, that intermedin could be important for physiological shown that the receptor profiles of CGRP and ADM in tissues are by endogenous in different studies on the between intermedin and CRLR/RAMP receptor complexes in different and tissues are to the of different in intermedin Furthermore, it demonstrated that CGRP and ADM overlap in receptor of these peptides binds to unique binding (5Poyner D.R. Sexton P.M. Marshall I. Smith D.M. Quirion R. Born W. Muff R. Fischer J.A. Foord S.M. Pharmacol. Rev. 2002; 54: 233-246Crossref PubMed Scopus (693) Google studies on the of intermedin and related peptides are essential for the of the signaling Among calcitonin/CGRP family peptides, ADM is as a hormone T. 2001; 22: PubMed Scopus Google Scholar, K. Kangawa K. M. Y. S. H. T. Res. PubMed Scopus Google Scholar, K. J. Kangawa K. M. H. T. Res. PubMed Scopus Google Scholar), whereas CGRP is important for sensory neurotransmission (3Amara S.G. Jonas V. Rosenfeld M.G. Ong E.S. Evans R.M. Nature. 1982; 298: 240-244Crossref PubMed Scopus (1754) Google Scholar, 9Zhang L. Hoff A.O. Wimalawansa S.J. Cote G.J. Gagel R.F. Westlund K.N. Pain. 2001; 89: 265-273Abstract Full Text Full Text PDF PubMed Scopus (135) Google Scholar, 10Salmon A.M. Damaj I. Sekine S. Picciotto M.R. Marubio L. Changeux J.P. Neuroreport. 1999; 10: 849-854Crossref PubMed Scopus (52) Google Scholar, 11Salmon A.M. Damaj M.I. Marubio L.M. Epping-Jordan M.P. Merlo-Pich E. Changeux J.P. Nat. Neurosci. 2001; 4: 357-358Crossref PubMed Scopus (94) Google Scholar, L. Mantyh P.W. Sternini C. Brecha N.C. Mantyh C.R. Brain Res. 1988; 463: 223-244Crossref PubMed Scopus (191) Google Scholar, M.G. S.G. J. Evans R.M. Nature. PubMed Scopus Google Scholar, S.G. Evans R.M. Rosenfeld M.G. Brown M.R. Nature. PubMed Scopus Google Scholar). In addition, ADM and as a to and T. 2001; 22: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, H. Kurihara N. Hirata K. S. T. T. Res. 1994; PubMed Scopus Google Scholar). Studies using mutant mice that ADM is for vascular during development (7Hay D.L. Smith D.M. Trends Pharmacol. Sci. 2001; 22: 57-59Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar, 8Shindo T. Kurihara Y. Nishimatsu H. Moriyama N. Kakoki M. Wang Y. Imai Y. Ebihara A. Kuwaki T. Ju K.H. Minamino N. Kangawa K. Ishikawa T. Fukuda M. Akimoto Y. Kawakami H. Imai T. Morita H. Yazaki Y. Nagai R. Hirata Y. Kurihara H. Circulation. 2001; 104: 1964-1971Crossref PubMed Scopus (260) Google Scholar), whereas is important for the of activity and inflammatory L. Hoff A.O. Wimalawansa S.J. Cote G.J. Gagel R.F. Westlund K.N. Pain. 2001; 89: 265-273Abstract Full Text Full Text PDF PubMed Scopus (135) Google Scholar, 10Salmon A.M. Damaj I. Sekine S. Picciotto M.R. Marubio L. Changeux J.P. Neuroreport. 1999; 10: 849-854Crossref PubMed Scopus (52) Google Scholar, 11Salmon A.M. Damaj M.I. Marubio L.M. Epping-Jordan M.P. Merlo-Pich E. Changeux J.P. Nat. Neurosci. 2001; 4: 357-358Crossref PubMed Scopus (94) Google Scholar). CRLR in different tissues could the actions of paralogous and the physiological of this receptor is on from cells the Because intermedin with CRLR/RAMP receptor the receptors for CGRP and ADM, intermedin could regulate diverse physiological functions that have to ADM or demonstrated in this intermedin blood pressure in both normal rats and as as the ADM and CGRP, that intermedin could regulate homeostasis T. 2001; 22: PubMed Scopus Google Scholar). studies have shown that CRLR and are in the and that CRLR is expressed in the S. B. Res. 2002; PubMed Scopus Google intermedin and related peptides blood pressure via the of CRLR/RAMP receptor complexes in vascular cells. with a intermedin treatment also The in by intermedin and related peptides could be a to the the to be the CRLR gene shown to be expressed in Res. 1998; PubMed Scopus Google in to the S. B. Res. 2002; PubMed Scopus Google Scholar, M. S. J. W. PubMed Scopus Google Scholar). Furthermore, intermedin could have and that are important for the regulation of and respiratory homeostasis T. 2001; 22: PubMed Scopus Google Scholar, A. K. M. T. H. J. Pharmacol. PubMed Scopus Google Scholar). Because intermedin is not in to the system using analysis, studies are to intermedin represents an endocrine hormone in the regulation of and studies on CGRP and ADM have shown that these peptides and the CRLR signaling system an important in gastrointestinal including and from the and G.J. PubMed Scopus Google Scholar, D.H. J. Pharmacol. PubMed Scopus Google Scholar). to studies on CGRP and ADM, intermedin to an and to emptying in that intermedin could have in the regulation of balance via a it is that the on is to in gastric Because intermedin is expressed in gastrointestinal intermedin could have additional in the gastrointestinal system that to be In of this it shown that CRLR is expressed in cells the of the and in and of the S. B. Res. 2002; PubMed Scopus Google Scholar). The that intermedin is expressed in the and of the pituitary to a for intermedin and the CRLR/RAMP signaling system in the regulation of pituitary hormone Although the of intermedin in the regulation of pituitary hormone not in this studies on ADM have shown that of ADM in K. J. Clin. PubMed Scopus Google Scholar, A.M. M.G. 2000; PubMed Scopus Google Scholar). it is that intermedin a in the regulation of pituitary studies on the expression of intermedin in the pituitary and other tissues during development are important for the of intermedin studies on the of peptide hormones have shown that pressure the of important or mature of polypeptide hormone The that the of the intermedin during that the of the intermedin the mature peptide and the that sequence provides important on the functional of gene sequence studies of intermedin from different showed that the sites of mature in whereas a is in that mature intermedin from diverse could be of and that a human intermedin could be the studies on human are to the mature of human Furthermore, the of vertebrate genomes will allow the identification and of additional peptide hormones on a on the profiling approach we used to intermedin and other novel peptide hormones Nat. Med. 2001; PubMed Scopus Google Scholar). In we have identified and a novel calcitonin/CGRP family gene and demonstrated that intermedin peptides are in diverse in and in vivo CRLR/RAMP intermedin is a physiological of and other mediated by the CRLR/RAMP receptor complexes. Although the peptide hormones β-CGRP, ADM, and are capable of with CRLR, optimal regulation by this signaling pathway on an of different in a tissue-specific and studies on tissue and endogenous of intermedin normal or are important to for diverse in and We and for and We J. W. and of and of for and for these and related