Figure 4. Time course of pulmonary hemorrhage (A), mortality rate (B) and PAF-AH level in serum (C) of gerbils inoculated with PBS, the avirulent strain of L. interrogans serovar Lai and L. interrogans serovar Lai.

PBS, injected with PBS alone; avirulent, injected with the avirulent strain of L. interrogans serovar Lai; virulent, injected with L. interrogans serovar Lai. (A) The measurement and plot of pulmonary hemorrhage referred to Materials and Methods . (C) Avirulent ^a, no pulmonary hemorrhage observed in the gerbils injected with the avirulent strain of L. interrogans serovar Lai; avirulent ^b, pulmonary hemorrhage observed in the gerbils injected with the avirulent strain of L. interrogans serovar Lai. At indicated time, number of animals was shown under the figures. Bar indicated the standard error.