Effects of urocortin II on neonatal rat cardiac myocytes and non-myocytes.
Urocortin (Ucn) II and III, homologous peptides of Ucn that are specific ligands for corticotropin-releasing hormone (CRH) type 2 receptor (CRH-R2), have recently been identified. The present study was designed to elucidate the effects of Ucn II, which is predominantly expressed in rodent heart, on neonatal rat cardiac myocytes (MCs) and cardiac non-myocytes (NMCs). Ucn II increased the incorporation of [3H]-leucine into MCs, as well as the accumulation of cAMP and the secretion of atrial natriuretic peptide. However, no significant changes were demonstrated in NMCs or an MC/NMC co-culture system. The effects of Ucn II were attenuated by astressin2-B, a specific antagonist of CRH-R2, and/or H89, an inhibitor of protein kinase A (PKA). These results indicate that Ucn II may be another endogenous cardiovascular substance that acts via CRH-R2 and the cAMP-dependent PKA pathway.
Ikeda
Keiichi
K
Department of Pharmacology (I), Jikei University School of Medicine, 3-25-8 Nishishinbashi, Tokyo 105-8461, Japan. ikedak@jikei.ac.jp
Tojo
Katsuyoshi
K
Otsubo
Chikara
C
Udagawa
Takashi
T
Hosoya
Tatsuo
T
Tajima
Naoko
N
Nakao
Kazuwa
K
Kawamura
Masahiro
M
D000818:Animals; D000831:Animals, Newborn; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D005260:Female; D008297:Male; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018019:Receptors, Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D054832:Urocortins
C101531:CRF receptor type 2; D018696:Neuroprotective Agents; D010446:Peptide Fragments; D018019:Receptors, Corticotropin-Releasing Hormone; D054832:Urocortins; C472610:atrial natriuretic peptide, rat; C104416:astressin; D009320:Atrial Natriuretic Factor; D003346:Corticotropin-Releasing Hormone; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases