Central stresscopin modulates cardiovascular function through the adrenal medulla in conscious rats.
Stresscopin (SCP or urocortin III), a member of the corticotropin-releasing factor (CRF) neuropeptide family, is a high-affinity ligand for the type 2 CRF receptor (CRF(2)). When administered peripherally, SCP suppresses food intake, delays gastric emptying and decreases heat-induced edema. Central administration of CRF produces marked hypertension and increased plasma catecholamine. However, the effects of SCP on the cardiovascular system are unknown. Thus, the present study compared the effects of intracerebroventricular (i.c.v.) administration of CRF and SCP on cardiovascular function. Central administration of SCP (0.05 or 0.5 nmol) elicited transient increases in mean arterial blood pressure (MABP) and heart rate (HR), and the higher dose of SCP (0.5 nmol) resulted in increased plasma epinephrine. In contrast, central administration of CRF provoked long-lasting increases in MABP, HR and plasma catecholamine levels (norepinephrine and epinephrine). Intravenously administered CRF and SCP (0.5 nmol) did not elicit significant changes in MABP and HR. Therefore, these data suggest that centrally administered SCP modulates cardiovascular function, likely through the sympatho-adrenal-medullary (SAM) system.
Chu
Chun-Ping
CP
Department of Physiology, Miyazaki Medical College, 5200 Kihara, Kiyotake-cho, Miyazaki-gun, Miyazaki 889-1692, Japan.
Qiu
De-Lai
DL
Kato
Kazuo
K
Kunitake
Takato
T
Watanabe
Shoichi
S
Yu
Nan-Shou
NS
Nakazato
Masamitsu
M
Kannan
Hiroshi
H
D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D002320:Cardiovascular Physiological Phenomena; D002319:Cardiovascular System; D002395:Catecholamines / Q000097:blood / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000502:physiology*; D004837:Epinephrine / Q000097:blood / Q000378:metabolism; D006339:Heart Rate; D007276:Injections, Intraventricular; D008024:Ligands; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018019:Receptors, Corticotropin-Releasing Hormone / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors; D054832:Urocortins
D002395:Catecholamines; D008024:Ligands; D012333:RNA, Messenger; D018019:Receptors, Corticotropin-Releasing Hormone; C426704:UCN3 protein, human; D054832:Urocortins; D003346:Corticotropin-Releasing Hormone; D009638:Norepinephrine; D004837:Epinephrine