Development of a system for evaluating XXXX inhibitors using @entity1 whole blood.

@entity1 @entity1437 @entity27696 @entity2604 @entity11902 @entity460 @entity3365 @entity375 @entity42430 @entity1473
A reliable system for evaluating @entity1437 (5-LO) pathway inhibitors employing @entity1 whole blood stimulated by the @entity460 ionophore, @entity3365 , and @entity375 cell walls (YCW) is described. In developing this system, we have shown that leukotriene B4 (LTB4) and @entity11902 ( @entity11902 ) can be recovered quantitatively from whole blood, and can be measured with accuracy and a precision (standard deviation) of +/- 12%. Apparent differences in LTB4/ @entity11902 levels between donors can be minimized by normalizing the LTB4/ @entity11902 production to neutrophil number. Variability in LTB4/ @entity11902 production among different donors was reduced by increasing the ionophore concentration. The kinetics of ionophore stimulated product production display a 1-4 min lag which is dependent on ionophore concentration. The lag is removed by pretreatment of blood with 5 micrograms/ml cytochalasin B. Likewise, the kinetics of product formation after stimulation with @entity375 cell walls demonstrated a lag period, which could be shortened by prior opsonization of the YCW. The amount of LTB4 metabolism to @entity27696 and 20- @entity1473 -LTB4 in this system is approximately 20%. @entity42430 , @entity2604 , and nafazatrom, known inhibitors of the 5-LO pathway, display half-maximal inhibition points of 0.4, 1.5, and 9 micrograms/ml, respectively. In summary, we believe that this assay offers a guide for predicting systemic levels of drug needed to be achieved for effective inhibition of cellular LTB4/ @entity11902 synthesis/release in @entity1 .
