title: Immobilization stress inhibits intimal fibromuscular proliferation in the process of arterial remodeling in rats.
abstract: We investigated role of beta-endorphin (END), which is released by immobilization stress, on intimal fibromuscular proliferation in a rat model of arterial remodeling after intimal injury. The endothelium of the abdominal aorta of Wistar-Kyoto rats was denuded, and the rats were subjected to immobilization stress (6 h/d), which raised the serum concentration of END, and intraperitoneal administration of either END (20 ng/kg/d) or naltrexone (NAL: 4 mg/kg/d). The proliferative activity (PA) of medial smooth muscle cells (SMCs) and the intima/media area ratio (R) were determined at 3 and 14 d after denudation, respectively. PA and R were significantly reduced by immobilization (PA: 64.8%, R: 34.6%), and NAL treatment completely reversed the decreases in PA and R. On the other hand, END reduced both PA and R (PA: 21.7% and R: 24.9%), and NAL also reversed the decreases in PA and R. END (20 pg/mL) inhibited both the proliferation (79% at 96 h) and migration (26%) of SMCs cultured with 5% fetal bovine serum in vitro, and NAL (100 microg/mL) reversed the inhibition of both activities. Our results suggest that immobilization stress stimulates the release of endogenous END, which then prevents both proliferation and migration of medial SMCs after intimal injury.
authors: Department of Geriatric Medicine, Kanazawa Medical University, Ishikawa, Japan.
authors: Kunimitsu
authors: K
authors: Iwai
authors: Takashi
authors: T
authors: Takahashi
authors: Takeshi
authors: T
authors: Nakahashi
authors: Koji
authors: K
authors: Nomura
authors: Mikiko
authors: M
authors: Atsumi
authors: Li
authors: L
authors: Zeng
authors: Keiichiro
authors: K
authors: Ishigami
authors: Tsugiyasu
authors: T
authors: Kanda
authors: Nobuo
authors: N
authors: Yamaguchi
authors: Shigeto
authors: S
authors: Morimoto
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000166:cytology* / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology* / Q000502:physiology; D019417:Hindlimb Suspension / Q000502:physiology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000502:physiology; D009271:Naltrexone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D018377:Neurotransmitter Agents / Q000494:pharmacology; D051381:Rats; D011921:Rats, Inbred WKY; D013312:Stress, Physiological / Q000503:physiopathology; D017539:Tunica Intima / Q000166:cytology; D017540:Tunica Media / Q000166:cytology; D001615:beta-Endorphin / Q000097:blood
chemical_list: D009292:Narcotic Antagonists; D018377:Neurotransmitter Agents; D009271:Naltrexone; D001615:beta-Endorphin