Immunomodulation of rat endometriotic implant growth and protein production

PROBLEM: The immune system has been implicated in the pathophysiology of endometriosis. To determine if modulation of the immune system influences endometriotic implant growth and protein production, the following experiment was conducted. METHOD: Female rats with surgically induced endometriosis were treated with either the immunosuppressive agent pentoxifylline (Pent; 5 mg/kg BW; N = 16) or a vehicle (N = 16) for 7 consecutive days, then killed. Twenty-four hours before death, 8 animals from each group were injected intraperitoneally with the immunostimulatory agent lipopolysaccharide (LPS; 200 micrograms/kg BW). At death, endometriotic implants were measured and protein production assessed by two-dimensional polyacrylamide gel electrophoresis. RESULT: Pentoxifylline significantly (P < 0.001) reduced endometriotic implant size (2.15 +/- 0.65 mm2 vs. 17.13 +/- 1.98 mm2) whereas LPS was without effect (18.32 +/- 2.57 mm2 vs. 17.13 +/- 1.98 mm2). Pentoxifylline also suppressed production of a portion of the proteins that comprise the implant specific group of proteins, ENDO-2, whereas LPS induced the production of two additional ENDO-2 proteins. CONCLUSION: Immunomodulatory agents can modulate rat endometriotic implant growth and production of implant-specific proteins.