Eicosanoids in Rat Brain during Ischemia and Reperfusion—Correlation to DC Depolarization

1990 ◽  
Vol 10 (3) ◽  
pp. 358-364 ◽  
Author(s):  
F. Tegtmeier ◽  
C. Weber ◽  
U. Heister ◽  
I. Haker ◽  
D. Scheller ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Rat Brain ◽  
Direct Current ◽  
Eicosatetraenoic Acid ◽  
Ischemia And Reperfusion ◽  
Ischemic Time ◽  
Isolated Perfused Rat Brain ◽  
Current Potential

The effects of complete ischemia on cerebral arachidonic acid (AA) metabolism were investigated in the isolated perfused rat brain. During 12.5 min of ischemia, AA, 5-hydroxy-6,8,11,14-eicosatetraenoic acid, and 15-hydroxy-5,8,11,13-eicosatetraenoic acid increased 129-, 4-, and 10-fold, respectively, while subsequent reperfusion for 30 min resulted in normalized levels independently of the duration of preceding ischemia. Prostaglandin (PG) F2α, PGE2, PGD2, 6-keto-PGF1α, and thromboxane (Tx) B2 remained at preischemic levels during 12.5 min of complete ischemia. However, at the end of subsequent reperfusion for 30 min, the levels of the prostanoids PGF2α, PGE2, PGD2, 6-keto-PGF1α, and TxB2 increased according to the preceding ischemic time. The levels reached a maximum after 7.5 min of ischemia and were elevated by 7-, 14-, 48-, 3-, and 30-fold, respectively. A prolongation of ischemia of up to 12.5 min was not associated with further increases of prostanoids at the end of reperfusion. The mechanisms underlying the metabolism of eicosanoids are discussed in relation to the changes of cortical direct current potential.

scholarly journals Lipopolysaccharides prime whole human blood and isolated neutrophils for the increased synthesis of 5-lipoxygenase products by enhancing arachidonic acid availability: involvement of the CD14 antigen.

1993 ◽  
Vol 178 (4) ◽  
pp. 1347-1355 ◽  
Author(s):  
M E Surette ◽  
R Palmantier ◽  
J Gosselin ◽  
P Borgeat
Keyword(s):  
Arachidonic Acid ◽  
Mononuclear Cells ◽  
Leukotriene B4 ◽  
Eicosatetraenoic Acid ◽  
Tnf Alpha ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Priming Activity

Stimulation of heparinized blood with 1 microM formyl-methionyl-leucyl-phenylalanine (FMLP) resulted in the formation of < 30 pmol/ml plasma of 5-lipoxygenase (5-LO) products. The preincubation of blood with 1 microgram/ml of lipopolysaccharide (LPS) (Escherichia coli 0111-B4) for 30 min before stimulation with FMLP resulted in the accumulation of 250-300 pmol of 5-LO products per ml plasma. The major products detected were leukotriene B4 and (5S)-hydroxy-6,8,11,14-eicosatetraenoic acid which were produced in equivalent amounts. The priming activity was detectable with as little as 1-10 ng LPS per ml blood and was optimal using 1-10 micrograms LPS/ml blood. The priming for 5-LO product synthesis was optimal after 20-30 min of preincubation with LPS and declined at preincubation times > 30 min. The priming effect of LPS was also observed using the complement fragment C5a or interleukin 8 as agonists. Polymorphonuclear leukocytes (PMN) and peripheral blood mononuclear cells accounted for 80 and 20% of the synthesis of 5-LO products, respectively. The ability of LPS to prime isolated PMN was dependent on the presence of plasma and was inhibited by the anti-CD14 antibody IOM2, indicating a CD14-dependent priming mechanism. The priming of whole blood with tumor necrosis factor alpha (TNF-alpha) and LPS was additive and the presence of mononuclear cells did not enhance the ability of LPS to prime PMN, indicating that the priming activity of LPS is independent of LPS-induced TNF-alpha synthesis. The mechanism by which LPS enhance 5-LO product synthesis in PMN was investigated. Treatment of PMN with LPS strongly enhanced the release of arachidonic acid after stimulation with FMLP. The release of arachidonic acid was optimal 2-3 min after stimulation with FMLP, attaining levels 5-15-fold greater than those observed in unprimed cells stimulated with FMLP. These results demonstrate that LPS dramatically increases the ability of blood to generate 5-LO products, and support the putative role of leukotrienes in pathological states involving LPS.

Effects of Hyperventilation and Hypoventilation on Cochlear Blood Flow and Endocochlear Direct-Current Potential

ORL ◽  
1995 ◽  
Vol 57 (4) ◽  
pp. 171-176 ◽  
Author(s):  
Hirofumi Yamamoto ◽  
Kazuo Makimoto ◽  
Michiro Kawakami ◽  
Yoshimitsu Ohinata ◽  
Hiroaki Takahashi
Keyword(s):  
Blood Flow ◽  
Direct Current ◽  
Cochlear Blood Flow ◽  
Current Potential

Arachidonic Acid Induces ARE/Nrf2-Dependent Heme Oxygenase-1 Transcription in Rat Brain Astrocytes

2017 ◽  
Vol 55 (4) ◽  
pp. 3328-3343 ◽  
Author(s):  
Chih-Chung Lin ◽  
Chien-Chung Yang ◽  
Yu-Wen Chen ◽  
Li-Der Hsiao ◽  
Chuen-Mao Yang
Keyword(s):  
Arachidonic Acid ◽  
Rat Brain ◽  
Heme Oxygenase ◽  
Heme Oxygenase 1
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