Effects of oral administration of heparan sulphate in the rat remnant kidney model

Heparins are useful for the protection of residual renal function in severa l nephropathies, but the anticoagulant action and the need of parenteral ad ministration are two main drawbacks limiting their use in chronic renal fai lure patients. Heparan sulphate (HS) is a heparin-like mucopolysaccharide d evoid of anticoagulant action and active orally. In this study, the effects of HS oral administration have been evaluated in 18 subtotally nephrectomi zed rats; 18 untreated remnant kidney rats served as control. No mortality was observed in the MS-treated rats, whereas in the control rats the surviv al rate was 72.2% at 18 weeks. At the end of the study, MS-treated rats sho wed lower urinary protein excretion (44 +/- 22 vs. 80 +/- 54 mg/ 24 h, p < 0.01), lower urea plasma levels (75 +/- 34 vs. 134 +/- 105 mg/dl, p < 0.01) and higher creatinine clearance (66 +/- 15 vs. 47 +/- 21 ml/min . 10(2), p < 0.05) than control rats. Remnant kidney weight (2.3 +/- 1.1 vs. 1.3 +/- 0.2 g, p < 0.01) and heart weight (1.3 +/- 0.2 vs. 1.1 +/- 0.1 g, p < 0.05) were greater in the control than in the MS-treated rats, as well as the sy stemic blood pressure values (167 +/- 19 vs. 115 +/- 32 mm Mg, respectively , p < 0.001). The remnant kidney histological examination in the HS-treated rats showed a lower prevalence of glomerular sclerosis, mesangial prolifer ation,and a much less evident tubulointerstitial damage than in controls. T he antiproliferative and anti-inflammatory actions of HS together with its protective action on the endothelium are the putative mechanisms that could account for our findings. In conclusion, the present study supports eviden ce of an antiproteinuric and a renoprotective effect of orally administered HS in subtotally nephrectomized rats. This is in keeping with the well-kno wn effects exerted also by other heparins, but the effectiveness of an oral ly available heparin-like product in this animal model could suggest the po ssibility of a clinical use also in progressing chronic renal failure patie nts.