PT  - JOURNAL ARTICLE
AU  - Yamaguchi, Yohei
AU  - Hosokawa, Susumu
AU  - Haraguchi, Go
AU  - Kajikawa, Yusuke
AU  - Sakurai, Makito
AU  - Ishii, Taku
AU  - Ando, Noboru
AU  - Morio, Tomohiro
AU  - Doi, Shozaburo
AU  - Furukawa, Tetsushi
TI  - The Anti-Inflammatory Effects and Clinical Potential of Dexmedetomidine in Pulmonary Arterial Hypertension
AID  - 10.1124/jpet.122.001399
DP  - 2023 May 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 88--94
VI  - 385
IP  - 2
4099  - http://jpet.aspetjournals.org/content/385/2/88.short
4100  - http://jpet.aspetjournals.org/content/385/2/88.full
SO  - J Pharmacol Exp Ther2023 May 01; 385
AB  - A pathogenic aspect of pulmonary arterial hypertension (PAH) is the aberrant pulmonary arterial smooth muscle cell (PASMC) proliferation. PASMC proliferation is significantly affected by inflammation. A selective α-2 adrenergic receptor agonist called dexmedetomidine (DEX) modulates specific inflammatory reactions. We investigated the hypothesis that anti-inflammatory characteristics of DEX could lessen PAH that monocrotaline (MCT) causes in rats. In vivo, male Sprague-Dawley rats aged 6 weeks were subcutaneously injected with MCT at a dose of 60 mg/kg. Continuous infusions of DEX (2 µg/kg per hour) were started via osmotic pumps in one group (MCT plus DEX group) at day 14 following MCT injection but not in another group (MCT group). Right ventricular systolic pressure (RVSP), right ventricular end-diastolic pressure (RVEDP), and survival rate significantly improved in the MCT plus DEX group compared with the MCT group [RVSP, 34 mmHg ± 4 mmHg versus 70 mmHg ± 10 mmHg; RVEDP, 2.6 mmHg ± 0.1 mmHg versus 4.3 mmHg ± 0.6 mmHg; survival rate, 42% versus 0% at day 29 (P < 0.01)]. In the histologic study, the MCT plus DEX group showed fewer phosphorylated p65-positive PASMCs and less medial hypertrophy of the pulmonary arterioles. In vitro, DEX dose-dependently inhibited human PASMC proliferation. Furthermore, DEX decreased the expression of interleukin-6 mRNA in human PASMCs treated with fibroblast growth factor 2 (FGF2). These consequences suggest that DEX improves PAH by inhibiting PASMC proliferation through its anti-inflammatory properties. Additionally, DEX may exert anti-inflammatory effects via blocking FGF2-induced nuclear factor κ B activation.SIGNIFICANCE STATEMENT Dexmedetomidine, a selective α-2 adrenergic receptor agonist utilized as a sedative in the clinical setting, improves pulmonary arterial hypertension (PAH) by inhibiting pulmonary arterial smooth muscle cell proliferation through its anti-inflammatory effect. Dexmedetomidine may be a new PAH therapeutic agent with vascular reverse remodeling effect.