Leukotriene B4 production in normal rat glomeruli.
The production of the lipoxygenase metabolite of arachidonic acid, leukotriene B4 (LTB4) by normal rat glomeruli has been studied. Isolated glomeruli from saline-perfused rat kidneys were incubated in Kreb's buffer for 15 min at 37 degrees C. The concentrations of LTB4 and other eicosanoids in cell-free supernatants were determined by direct radioimmunoassays (RIA). Mean basal syntheses of eicosanoids were: thromboxane B2 (TXB2) 0.77 +/- 0.13, prostaglandin (PG) E2 0.40 +/- 0.05, 6-keto-PGF1 alpha 0.38 +/- 0.06 ng/mg glomerular protein (mean +/- SEM n = 8). In these assays immunoreactive LTB4 synthesis was 0.12 +/- 0.02 ng/mg. In samples incubated with BW755C, 50 micrograms/ml, an inhibitor of arachidonate metabolism via both the cyclo-oxygenase and lipoxygenase pathways, there was more than 80% inhibition of the synthesis of TXB2, PGE2 and 6-keto-PGF1 alpha. However, immunoreactive LTB4 was only reduced by 44%, suggesting the presence of other materials which cross-react in the RIA. The presence of authentic LTB4 in the supernatants was confirmed after extraction and high-pressure liquid chromatography (HPLC). This material represented 25% of the original material detected by RIA. Although the physiological role of LTB4 in the normal state is unknown, its chemotactic activity may be of great significance during glomerular inflammation.
Cattell
V
V
Cook
H T
HT
Smith
J
J
Salmon
J A
JA
Moncada
S
S
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D007678:Kidney Glomerulus / Q000378:metabolism*; D007975:Leukotriene B4 / Q000378:metabolism*; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D011917:Rats, Inbred Lew
D007975:Leukotriene B4