[A study on bactericidal/permeability increasing protein (BPI) as a natural inhibitor of endotoxin]

To investigate the existential status of BPI as a natural defensive factor in human polymorphonuclear leukocytes (PMNL).

The abilities of porcine BPI to combine endotoxin (lipopolysaccharide, LPS) and inhibit the release of TNFalpha from hepatic Kupffer's cells were examined. And the expression of BPI in PMNL after stimulation by LPS was determined by flow cytometry.

The ability of porcine BPI to combine LPS was increased along with the increment of BPI concentration. The effects of the BPI on the inhibition of the release of TNFalpha from hepatic Kupffer's cells were dose-dependant. The expression of BPI in PMNL was enhanced obviously within 30 mins of LPS stimulation. But there was no immediate release of BPI into blood.

BPI possessed potential power of neutralizing LPS. It might be beneficial to supplement exogenous BPI in case of Gram negative bacterial infection.