Blood-brain barrier breakdown by PAF and protection by XQ-1H due to antagonism of PAF effects.
Hypoxia and reoxygenation set in motion a series of events, including blood-brain barrier breakdown. We examined the content and effect of platelet-activating factor (PAF), which was increased in the rat brain microvessel endothelial cells (RBMECs) during hypoxia and reoxygenation. MTT method was used to assay cell damage; ELISA analysis was used to estimate PAF release after hypoxia and reoxygenation injury; and RT-PCR and Western blotting method were used to assess gene and protein expressions of inducible nitric-oxide synthase (iNOS) in RBMECs under PAF damage. PAF affected intracellular free Ca(2+) levels, increasing [Ca(2+)](i), which caused up-regulation of iNOS. We also examined the blood-brain barrier protective effect of XQ-1H, a novel ginkgolide B derivative. Pretreatment with XQ-1H (10 microM and 3 microM) for 24 h significantly antagonized PAF receptor and inhibited the increase in intracellular calcium concentration and the up-regulation of iNOS in response to PAF under hypoxia and reoxygenation in vitro.
Deng
Yan
Y
Department of Physiology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
Fang
Weirong
W
Li
Yunman
Y
Cen
Juan
J
Fang
Fang
F
Lv
Peng
P
Gong
Shubo
S
Mao
Lishun
L
D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000378:metabolism; D001921:Brain / Q000098:blood supply; D002118:Calcium / Q000378:metabolism; D015687:Cell Hypoxia; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D046934:Ginkgolides / Q000494:pharmacology*; D007783:Lactones / Q000494:pharmacology*; D055806:Microvessels / Q000166:cytology; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis / Q000235:genetics; D010100:Oxygen / Q000378:metabolism; D010972:Platelet Activating Factor / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors*; D015854:Up-Regulation / Q000187:drug effects
D046934:Ginkgolides; D007783:Lactones; D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C544311:XQ-1H compound; C039351:platelet activating factor receptor; D052247:Nitric Oxide Synthase Type II; D010100:Oxygen; D002118:Calcium