NEPHRECTOMY ENHANCES INTERLEUKIN-6 SECRETION BY INTERLEUKIN 1-STIMULATED MESANGIAL CELLS IN-VITRO

Background: Kidney mesangial cells are capable of producing and respon ding to interleukin 6 (IL-6). In experimental glomerulonephritis mesan gial cell proliferation correlates with increased IL 6 production. To investigate the involvement of IL-6 in post;nephrectomy compensatory h ypertrophy, we studied the capacity of mesangial cells from single rem aining kidneys to secrete IL-6 in culture. Methods: Mesangial cells we re obtained from uni-nephrectomized or sham-nephrectomized Charles Riv er rats. Cell cultures were maintained for 8 days in DMEM/FI2HAM mediu m supplemented with IL-1 of interferon (IFN). IL-6 production was meas ured using an IL-6-depenent B9 human hybridoma cell line. Result: IL-6 production by mesangial cells from normal kidneys was significantly e nhanced by IL-1, compared to unstimulated cells (p<0.01), and the incr ease was significantly greater in mesangial cells from a single remain ing kidney (p<0.01). All cultures grown in control medium or with addi tion of IFN produced similar amounts of IL-6. Conclusion: Mesangial ce lls from single remaining kidneys in culture maintain an exaggerated c apacity to produce IL-6 in response to IL-1. IL-6 was reported to enha nce or inhibit mesangial cell proliferation in vitro. We suggest that the local over production of IL-6 by a single remaining kidney may pla y a role in regulating a sequence of physiological events in compensat ory renal growth, initially stimulating mesangial cell proliferation a nd later blunting the process.