Inhibition of mesothelial cell growth and protein synthesis by heparin.

Heparin, routinely used in peritoneal dialysis, has been found to have various effects, mainly inhibitory. Its infusion into the peritoneal cavity may adversely affect mesothelial cell growth and regeneration. Thus we wished to determine if heparin inhibits mesothelial cell growth and is does-dependent. Rat mesothelial cells were incubated for 3 days and 6 days with 200, 100, 20, 2, and 0.5 U/mL of heparin. Cellular proliferation and protein synthesis were determined by liquid scintillation counting after 24-hour pulses with 3H-thymidine and 3H-leucine. Heparin at 2 and 0.5 U/mL had no significant effect on radionuclide uptake. At 100 U/mL heparin inhibited radionuclide uptake by at least 50%. These findings indicate that heparin in small concentrations may be harmless, but at higher concentrations is inhibitory to mesothelial cell growth and proliferation.