THE INTERACTION OF GLOMERULAR MESANGIAL CELLS AND EPITHELIAL-CELLS

The interaction of cells within the glomerulus plays an important role in the development and progression of glomerular disease. To investig ate the interaction of glomerular mesangial cells (GMC) and epithelial cells (GEC), and mediator(s) of this interaction, we investigated the effect of Adriamycin (doxorubicin hydrochloride)-induced (ADR) rat GM C-conditioned medium (GMC-CM) on the incorporation of S-35, H-3-leucin e, and H-3-thymidine in normal rat GEC, as well as 3H-thymidine uptake by normal rat GMC in response to ADR-rat GEC-CM. In addition, changes in the responsiveness to interleukin-6 (IL-6) and the products of IL- 6 were assessed in ADR-rat GMC, The results showed that: (1) GMC-CM of ADR-rat with heavy proteinuria stimulated GEC proliferation and the s ynthesis of sulfated compounds and protein, while the GEC-CM of ADR-ra t from the same nephrotic period increased GMC proliferation; (2) the ADR-rat GMC had altered responsiveness to IL-6 and its products. The s timulation index results demonstrated the interaction of GMC and GEC i n the ADR-induced rat model, and that this interaction related closely to the degree of proteinuria and was mediated by soluble products of the damaged glomerular cell.