Figure 6.

Mean (+SEM) splenocyte proliferation in response to various concentrations of LPS (E. coli O26:B6) by cells collected from adult ENDO and SALINE rats immediately after exposure to 30 min of restraint stress or in nonstressed controls. Lymphocyte proliferation was determined by measuring incorporation of [³H]thymidine in 5 × 10⁵ cells incubated (37°C, 5% CO₂) with LPS for 44 h and a further incubation for 4 h after the addition of 1 μCi of [³H]thymidine per well. Cells were harvested on a 96-well harvester and cpm was determined. Restraint stress significantly reduced splenocyte proliferation in ENDO animals; however, this effect was not observed in stressed SALINE animals (*, P < 0.05). These data suggest that ENDO animals can mount a proliferative response to LPS equivalent to controls, but their lymphocytes are more sensitive to “stress factors.”