title: Long-term treatment with a Rho-kinase inhibitor improves monocrotaline-induced fatal pulmonary hypertension in rats.
abstract: Primary pulmonary hypertension is a fatal disease characterized by endothelial dysfunction, hypercontraction and proliferation of vascular smooth muscle cells (VSMCs), and migration of inflammatory cells, for which no satisfactory treatment has yet been developed. We have recently demonstrated that intracellular signaling pathway mediated by Rho-kinase, an effector of the small GTPase Rho, is involved in the pathogenesis of arteriosclerosis. In the present study, we examined whether the Rho-kinase-mediated pathway is also involved in the pathogenesis of fatal pulmonary hypertension in rats. Animals received a subcutaneous injection of monocrotaline, which resulted in the development of severe pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular lesions in 3 weeks associated with subsequent high mortality rate. The long-term blockade of Rho-kinase with fasudil, which is metabolized to a specific Rho-kinase inhibitor hydroxyfasudil after oral administration, markedly improved survival when started concomitantly with monocrotaline and even when started after development of pulmonary hypertension. The fasudil treatment improved pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular lesions with suppression of VSMC proliferation and macrophage infiltration, enhanced VSMC apoptosis, and amelioration of endothelial dysfunction and VSMC hypercontraction. These results indicate that Rho-kinase-mediated pathway is substantially involved in the pathogenesis of pulmonary hypertension, suggesting that the molecule could be a novel therapeutic target for the fatal disorder.
authors.affiliation: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Abe
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shimokawa
authors.forename: Keiko
authors.initials: K
authors.lastname: Morikawa
authors.forename: Toyokazu
authors.initials: T
authors.lastname: Uwatoku
authors.forename: Keiji
authors.initials: K
authors.lastname: Oi
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hattori
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakashima
authors.forename: Kozo
authors.initials: K
authors.lastname: Kaibuchi
authors.forename: Katsuo
authors.initials: K
authors.lastname: Sueishi
authors.forename: Akira
authors.initials: A
authors.lastname: Takeshit
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000401:mortality / Q000517:prevention & control*; D017380:Hypertrophy, Right Ventricular / Q000503:physiopathology / Q000517:prevention & control; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D016686:Monocrotaline; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D011651:Pulmonary Artery / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015996:Survival Rate; D013997:Time Factors; D054460:rho-Associated Kinases
chemical_list: D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; C431085:hydroxyfasudil; D016686:Monocrotaline; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; C049347:fasudil