Mitogenic effects of epidermal growth factor and platelet-derived growth factor on canine and equine mesangial cells in vitro.

OBJECTIVE

To evaluate the effects of epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) on canine and equine mesangial cell (MC) proliferation in vitro.

SAMPLE POPULATION

Third- through eighth-passage canine and equine MC were obtained from explant outgrowth after differential sieving of glomeruli isolated from the kidneys of clinically normal dogs and horses.

PROCEDURE

Mitogenic effects of serum, insulin, EGF, and PDGF were evaluated in MC by induction of DNA synthesis, measured as stimulation of [3H]thymidine incorporation and increase in cell numbers.

RESULTS

Epidermal growth factor was a potent mitogen in canine and equine MC, stimulating dose-dependent increases in [3H]thymidine incorporation and moderate increase in cell numbers. Although PDGF alone did not significantly stimulate [3H]thymidine incorporation in canine MC, PDGF was synergistic with EGF in stimulation of [3H]thymidine incorporation in canine and equine MC, and PDGF significantly stimulated [3H]thymidine incorporation in equine MC.

CONCLUSIONS

Both EGF and PDGF are important mediators of canine and equine MC proliferation.

CLINICAL RELEVANCE

Our results are consistent with the hypothesis that growth factors have a role in the progression of glomerular disease in dogs and horses. These findings could prove to be of diagnostic, prognostic, and therapeutic value in the management of spontaneous renal disease in these species.