[Compensatory changes in beta 2-microglobulin handling in the remnant tubules after contralateral nephrectomy. Observations of beta 2-microglobulin excretion into the urine].

Serum and urinary beta 2-microglobulin (S-, U-beta 2MG), and creatinine clearance (C-cr) were examined in 41 nephrectomy cases, and changes in glomerular and tubular handling of beta 2MG such as filtered beta 2MG (Fil-beta 2MG), reabsorption of beta 2MG (Reab-beta 2MG) and fractional excretion of beta 2MG (FE-beta 2MG) were studied. Serum creatinine (S-cr) and S-beta 2MG increased significantly after nephrectomy. C-cr decreased immediately after nephrectomy (80%), but recovered up to 87% in 2 to 4 days postoperatively. Fil-beta 2MG decreased immediately after nephrectomy, but increased up to more than the preoperative level in 2 to 4 days postoperatively. On the other hand, Reab-beta 2MG decreased significantly immediately after nephrectomy, and it took 5 to 8 days until recovery. Consequently, urinary excretion of beta 2MG (Ex-beta 2MG) and FE-beta 2MG increased significantly 0 to 4 days postoperatively. These increases in Ex-beta 2MG and FE-beta 2MG were much higher than those seen in diabetic nephropathy, cadmium nephropathy and Cis-diamminedichloroplatinum (II) (CDDP) intoxication, and were not due to drug intoxication such as general anesthesia or antibiotics, but due to glomerulo-tubular unbalance. Clinical data of renal tubular handling of beta 2-microglobulin in cases of interferon therapy or unilateral nephrectomy revealed many interesting aspects of glomerulo-tubular adaptations, and micropuncture study or isolated tubule perfusion study are awaited.