In addition to its effects on thymocytes, testicular IF completely inhibited [3H]thymidine incorporation by mature T cells (peripheral blood lymphocytes or rat spleno-cytes) stimulated with PHA (data not shown) or the anti-Tcell receptor antibody R73 (Fig. ЗА). Inhibition below the unstimulated level of [3H]thymidine incorporation was also observed in the splenocyte cultures (Fig. ЗА). In contrast, IF over the same range of doses stimulated [3H] thymidine incorporation by the non-lymphocytic K562 erythroid cell line (Fig. 3B). buy antibiotics online
Comparison of IF and Serum
Platelet-depleted serum had an inhibitory effect on T-cell proliferation in vitro (Fig. 4), but the dose-response characteristics were very different from those of testicular IF, with IF considerably more effective (4- to 8-fold). In contrast, a pooled sample of aqueous humor from normal adult rats had no effect at doses up to 10 |xl (data not shown).
FIG. 3. Specificity of inhibitory activity. A) [3H]Thymidine incorporation by rat splenocytes in the absence of stimulation, in the presence of R73 T-cell receptor antibody (+), and in the presence of R73 and normal rat testicular IF (circles). B) [3H]Thymidine incorporation by K562 cells over 20 h in vitro in the presence of rat IF. Values are mean ± SEM, n = 4 replicate wells. Values with same letter superscript are not significantly different (p < 0.05).
FIC. 4. Log dose-log response comparison of normal rat testicular IF (open circles) and platelet-depleted serum (solid circles) in the rat thymocyte proliferation assay. Values are mean ± SEM, n = 4 replicate wells. Comparisons are with the control (PHA alone) response: *** p < 0.001; ** p < 0.01; * p < 0.05; ns, not significantly different (p > 0.05).