oh yes! most definitely. the kidney's are the final processing place for the mercury before its excreted in the urine. if you are using DMSA then the kidneys are involved for sure.
getting plenty of potassium? vit C? B5? all critical for kidney function.
if you are doing on/off DMSA cycles, then next off cycle you might want to do an herbal kidney cleanse
and/or juice fast.