Adrenocorticotropic hormone-releasing activity of urotensin I and its fragments in vitro.
Adrenocorticotropic hormone (ACTH)-releasing activity of synthetic carp Urotensin I (UI) and its ten synthetic fragments were examined using cultured rat pituitary cells. Both UI(1-41) and rat CRF (rCRF) increased ACTH release in a similar fashion at a concentration range from 10 pM to 100 nM. The potency of UI(1-41) was about one seventh that of rCRF on a molar basis. Four of ten UI fragments, UI(1-36), UI(4-36), UI(6-36) and UI(1-19) showed relatively strong ACTH-releasing activity, whereas both UI(9-36) and UI(17-36) showed extremely weak ACTH-releasing activity. However, all these fragments showed the activity in a dose-dependent manner parallel with that of UI(1-41). The activity of UI(1-36) was weaker than UI(1-41), suggesting that the C-terminal 37-41 sequence is required to express the full ACTH-release activity, although each of four C-terminal fragments, UI(24-36), UI(24-41), UI(29-36) and UI(29-41), exhibited no activity. In summary, the 4-19 amino acid sequence of UI(is important to exhibit ACTH-releasing activity and the C-terminal 37-41 sequence will be necessary to express the full activity.
Ohta
N
N
Research Laboratory, Zenyaku Kogyo Co., Ltd., Tokyo, Japan. ohta@zenyaku.co.jp
Mochizuki
T
T
Hoshino
M
M
Jun
L
L
Kobayashi
H
H
Yanaihara
N
N
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002347:Carps; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003346:Corticotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology*; D010902:Pituitary Gland / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D018019:Receptors, Corticotropin-Releasing Hormone / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D014579:Urotensins / Q000138:chemical synthesis / Q000302:isolation & purification / Q000494:pharmacology*
D010446:Peptide Fragments; D018019:Receptors, Corticotropin-Releasing Hormone; D011994:Recombinant Proteins; D014579:Urotensins; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; C029676:urotensin I; C045089:corticotropin releasing hormone (9-41)