EFFECT OF INTERLEUKIN-8 ON GLOMERULAR SULFATED COMPOUNDS AND ALBUMINURIA

To evaluate the effect of interleukin-8 (IL8) on glomerular basement m embrane (GEM) sulfated compounds and albuminuria, we infused IL8 in 1% bovine serum albumin (BSA) for 5 days into the left renal artery of H oltzman male rats at the rate of 10 mu l/h using an osmotic pump. Cont rol rats received 1% BSA. A significant increase in urinary albumin/cr eatinine ratio was seen on the last day of as infusion (0.38 +/- 0.11, mean +/- SEM) when compared with albumin/creatinine ratio prior to in fusion (0.19 +/- 0.04, P = 0.04). No significant differences in urinar y albumin excretion prior to and after infusion of 1% BSA were observe d. On the last day of infusion, rats were injected with (35)sulfate (1 .0 mCi/200 g body weight) intraperitoneally and killed after 8 h. Glom eruli were isolated and GEM obtained. After 5 days of IL8 administrati on, there was a significant increase in (35)sulfate uptake by GEM of t he infused kidney (76 + 10 cpm/dry glomerular weight, mean +/- SEM) co mpared with the uptake seen in the contralateral kidney (53 +/- 9, P = 0.05). The in vivo infusion of IL8 increased the (35)sulfate uptake b y GEM and augmented the urinary albumin/creatinine ratio, suggesting t hat IL8 may induce albuminuria by altering the metabolism of the GEM s ulfated compounds. This hypothesis needs to be confirmed by studies on glomerular charge selectivity and GEM anionic sites during the course of the infusion. Moreover, the persistence of the effect needs to be evaluated by prolonging the infusion for more than 5 days.