Effects of TEL on the Composition of BAL in LPS-Nebulized Mice
We analyzed the effect of a single intraperitoneal (IP) dose of TEL (20 mg/kg) on the recruitment of cells in lungs after LPS aerosol exposure. As shown in Figure 6, the inhalation of LPS elicited a massive accumulation of leukocytes in BAL fluid, and flow cytometry analysis revealed a major contribution of neutrophils among the accumulated cells. TEL pretreatment (1 h before LPS stimulation) induced a significant reduction in both total cell counts and neutrophil counts at 4 h after LPS exposure (p < 0.05 in both cases) [Fig 6, top, A]; the variations in macrophages were negligible Viagra Australia. A similar picture was observed at 24 h after nebulization (p < 0.005 in both cases) [Fig 6, bottom, B].
Untreated controls and mice that received TEL, LPS, or TEL plus LPS did not differ significantly in terms of the protein levels found in BAL fluid during the first 4 h after LPS exposure; however, at 24 h after LPS there was a dramatic increase in protein concentration, which was reduced by 25% (p < 0.01) in TEL-pretreated mice (Fig 7, top, A). Similarly, when BAL fluid was collected at 24 h after LPS exposure, the concentrations of nitrite (a stable metabolite of the nitric oxide [NO] produced by iNOS) was reduced by 20% (p < 0.05) as a consequence of the pretreatment with TEL (Fig 7, bottom, B).
We also measured the levels of MIP-2 and TNF-a in BAL fluid samples. The levels of MIP-2 markedly rose at 4 h after LPS exposure and dropped at 24 h; in both cases, pretreatment with TEL induced significant reductions (38% [p < 0.05] and 23% [p < 0.05], respectively) [Fig 8, top, A]. The levels of TNF-a showed a similar kinetic, and were reduced by 49% (p < 0.005) and 60% (p < 0.005) in BAL fluid samples from TEL-pretreated mice that were killed at 4 and 24 h, respectively, after LPS exposure (Fig 8, bottom, B).