Adrenomedullin receptors in rat choroid plexus.
To characterize transmembrane signaling of adrenomedullin (AM) in the choroid plexus, we studied the effects of AM on cyclic AMP (cAMP) and cyclic GMP (cGMP) levels as well as expression of mRNA for AM receptor in the rat choroid plexus slices. AM or calcitonin gene-related peptide (CGRP) increased cAMP (but not cGMP) level in a concentration-dependent manner, with AM being much more potently than CGRP. AM mRNA as well as calcitonin-receptor-like receptor mRNA and receptor-activity-modifying protein 2 mRNA, were highly expressed in the choroid plexus. Our biochemical and pharmacological studies may raise the possibility that choroid plexus secretes AM into the cerebrospinal fluid, and AM regulates choroid plexus function in an autocrine/paracrine manner via acting on AM-specific receptors.
Kobayashi
H
H
Department of Pharmacology, Miyazaki Medical College, 5200 Kihara, Kiyotake, 889-1692, Miyazaki, Japan. hkobayas@post.miyazaki-med.ac.jp
Shiraishi
S
S
Minami
S
S
Yokoo
H
H
Yanagita
T
T
Saitoh
T
T
Mohri
M
M
Wada
A
A
D053607:Adrenomedullin; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology; D058286:Calcitonin Receptor-Like Protein; D002831:Choroid Plexus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D009599:Nitroprusside / Q000494:pharmacology; D010455:Peptides / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D058261:Receptor Activity-Modifying Proteins; D058265:Receptors, Adrenomedullin; D018003:Receptors, Calcitonin / Q000096:biosynthesis / Q000235:genetics; D018000:Receptors, Peptide / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects
D058286:Calcitonin Receptor-Like Protein; C545580:Calcrl protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D010455:Peptides; D012333:RNA, Messenger; D058261:Receptor Activity-Modifying Proteins; D058265:Receptors, Adrenomedullin; D018003:Receptors, Calcitonin; D018000:Receptors, Peptide; D053607:Adrenomedullin; D009599:Nitroprusside; D000242:Cyclic AMP; D006152:Cyclic GMP; D015740:Calcitonin Gene-Related Peptide