The neuroprotective effect of a novel calmodulin antagonist, 3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate, in transient forebrain ischemia.
A novel calmodulin (CaM) antagonist DY-9760e, (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate), with an apparent neuroprotective effect in vivo, potently inhibits CaM-dependent nitric oxide synthase in situ. In the present study, we determined whether DY-9760e inhibits nitric oxide (NO) production and protein nitration by peroxynitrite (ONOO(-)) formation in the hippocampal CA1 region of gerbils after transient forebrain ischemia. In freely moving gerbils, NO production after 10-minute forebrain ischemia was monitored consecutively with in vivo brain microdialysis. Pretreatment with DY-9760e (50 mg/kg i.p.) significantly decreased the increased levels of NO(x)(-) (NO metabolites, NO(2)(-) plus NO(3)(-)) immediately after, 24 h after cerebral ischemia-reperfusion to the control levels of sham-operated animals. Western blot and immunohistochemical analyses using an anti-nitrotyrosine antibody as a marker of ONOO(-) formation indicated a marked increase in nitrotyrosine immunoreactivity in the pyramidal neurons of the CA1 region 2 h after reperfusion, and DY-9760e significantly inhibited increased nitrotyrosine immunoreactivity. Coincident with the inhibition of the NO production and protein tyrosine nitration, pretreatment with DY-9760e rescued the delayed neuronal death in the hippocampal CA1 region. These results suggest that the inhibitory effects of DY-9760e on the NO-ONOO(-) pathway partly account for its neuroprotective effects in cerebral ischemia.
Hashiguchi
A
A
Department of Pharmacology, Kumamoto University School of Medicine, Kumamoto-city, Kumamoto 860-0811, Japan.
Kawano
T
T
Yano
S
S
Morioka
M
M
Hamada
J
J
Sato
T
T
Shirasaki
Y
Y
Ushio
Y
Y
Fukunaga
K
K
D000818:Animals; D015153:Blotting, Western; D002545:Brain Ischemia / Q000517:prevention & control*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D020215:Carotid Artery, Internal, Dissection; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005849:Gerbillinae; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007150:Immunohistochemistry; D007191:Indazoles / Q000627:therapeutic use*; D002546:Ischemic Attack, Transient / Q000473:pathology*; D008297:Male; D017551:Microdialysis; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D009569:Nitric Oxide / Q000378:metabolism; D015424:Reperfusion / Q000379:methods; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
C109602:3-(2-(4-(3-chloro-2-methylphenyl)1-piperazinyl)ethyl)5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazol dihydrochloride 3.5 hydrate; D002147:Calmodulin; D004791:Enzyme Inhibitors; D007191:Indazoles; D018696:Neuroprotective Agents; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D019331:NG-Nitroarginine Methyl Ester