Bacterial clearance in mice assessed by a conductance method is enhanced by RU 41740 (Trade name Biostim®)

Conductance measurements were used to determine the bacterial concentrations in the blood of mice receiving a suspension of Escherichia coli by the intravenous route. The study was also carried out on animals that had been treated with a drug (RU 41740) that stimulates the reticuloendothelial system. The intensity of the in vivo phagocytosis was assessed by calculating the difference between the mean detection times of the treated and control groups (ΔDT). The results obtained by conductance measurements were not statistically different from those obtained by the standard method of counting on Petri dishes. The conductance measurement method was also compared with the carbon clearance test, the reference test for studying in vivo phagocytosis. The two clearance tests revealed a major stimulation of the reticuloendothelial system by RU 41740. The coefficient of variation was lowest in the case of the bacterial clearance test.