Effects of a calcium-channel blocker (CV159) on hepatic ischemia/reperfusion injury in rats: evaluation with selective NO/pO2 electrodes and an electron paramagnetic resonance spin-trapping method.
Nitric oxide (NO) and the partial pressure of oxygen (pO(2)) in the liver were simultaneously quantified in rats with partial hepatic ischemia/reperfusion injury (PHIRI). Real-time NO/pO(2) monitoring and immunohistochemical analysis for superoxide dismutase and inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) were performed to evaluate the protective effects of a dihydropyridine-type calcium-channel blocker--CV159--on PHIRI. Serum high-mobility-group box-1 (HMGB-1) was measured to assess cellular necrosis. Moreover, we used in vitro/ex vivo electron paramagnetic resonance spin trapping to assess the hydroxyl radical (*OH)-scavenging activity (OHSA) of CV159 and the liver tissue. The NO levels were significantly higher in CV159-treated rats than in control rats throughout the ischemic phase. Immediately after reperfusion, the levels temporarily increased in waves and then gradually decreased in the treated rats but remained constant in the control rats. pO(2) was continually higher in the treated rats. In these rats, hepatic eNOS expression increased, whereas iNOS expression decreased. The treated rats exhibited significantly higher cytosolic and mitochondrial concentrations NOx (NO(2)+NO(3)). The serum HMGB-1 levels significantly decreased in the treated rats. Moreover, CV159 directly scavenged *OH and both mitochondrial and cytosolic OHSA were preserved in the treated rats. Thus, CV159-mediated inhibition of intracellular Ca(2+) overloading may effectively minimize organ damage and also have *OH-scavenging activity and the cytoprotective effects of eNOS-derived NO.
Hataji
Keizo
K
Department of Gastroenterological and General Surgery, St. Marianna University Hospital, Kawasaki, Japan.
Watanabe
Taiji
T
Oowada
Shigeru
S
Nagaya
Masaki
M
Kamibayashi
Masato
M
Murakami
Eiichi
E
Kawakami
Hiroyoshi
H
Ishiuchi
Atsuko
A
Kumai
Toshio
T
Nakano
Hiroshi
H
Kobayashi
Shinichi
S
Otsubo
Takehito
T
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology / Q000627:therapeutic use*; D003600:Cytosol / Q000378:metabolism; D004095:Dihydropyridines / Q000494:pharmacology / Q000627:therapeutic use*; D004566:Electrodes; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D004727:Endothelium / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology / Q000627:therapeutic use; D024243:HMGB1 Protein / Q000097:blood; D017665:Hydroxyl Radical; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D009336:Necrosis / Q000378:metabolism / Q000517:prevention & control*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009589:Nitrogen Oxides / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000517:prevention & control*
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D016166:Free Radical Scavengers; D024243:HMGB1 Protein; D009589:Nitrogen Oxides; D009569:Nitric Oxide; D017665:Hydroxyl Radical; C055634:CV 159; D019001:Nitric Oxide Synthase; D010100:Oxygen