Low concentrations of intravenous polygelines promote low-molecular weight proteinuria

Background Previously we observed that atrial natriuretic peptide (ANP)-induced albuminuria was accompanied by an increase in urinary excretion of the low-molecular weight protein (LMW protein) beta(2)-microglobulin (beta(2)-m), suggesting that the albuminuria may at least partly be the result of blockade of tubular protein reabsorption. However, in our experiments ANP was dissolved in the polygeline Haemaccel((R)) (Hoechst, Behring-Werke, Marburg Germany) to prevent adhesion of ANP to the infusion system. Anecdotal reports have shown that high dosages of polygelines such as Haemaccel((R)) or Gelofusine((R)) (Braun NPBI Oss, the Netherlands) may influence tubular protein handling. In the present study we have evaluated the effect of a low and high doses of the polygeline Haemaccel((R)) on proteinuria. In addition, we have reassessed the effects of ANP. Materials and methods. We measured urinary beta(2)-microglobulin (beta(2)-m) and albumin excretion in healthy volunteers after infusion of a high-dose pure Haemaccel((R)) (0.04 mL kg(-1) min(-1) for 60 min), a low-dose Haemaccel((R)) (0.01 mL kg(-1) min(-1) for 60 min followed by infusion of 0.02 mL kg(-1) min(-1) for 60 min) and a low-dose Gelofusine((R)) (dose comparable to the low-dose Haemaccel((R))). In addition we performed similar studies using ANP dissolved in saline and Haemaccel((R)). Results Infusion of Haemaccel((R)) caused a dose-dependent increase in urinary excretion of beta(2)-m. There were no differences between Haemaccel((R)) and Gelofusine((R)). After infusion of ANP dissolved in Haemaccel((R)) urinary beta(2)-m excretion increased from 0.05 +/- 0.03 mug min(-1) to 27 +/- 10 mug min(-1) and urinary albumin excretion increased from 4.5 +/- 1.1 mug min(-1) to 9.7 +/- 6.3 mug min(-1) (P < 0.05). During ANP + saline infusion, urinary beta(2)-m excretion did not change, whereas the urinary albumin excretion increased from 5.3 +/- 1.5 mug min(-1) to 7.9 +/- 2.4 mug min(-1) (P < 0.05). Conclusions Our study demonstrates that even low doses of the polygelines Haemaccel((R)) and Gelofusine((R)) profoundly attenuate the tubular reabsorption of the low-molecular weight protein beta(2)-m. Atrial natriuretic peptide does not affect tubular protein reabsorption. Therefore, the rise in albuminuria during ANP infusion most likely reflects alterations in glomerular permeability.