Acidic polyanion poly(acrylic acid) prevents calcium oxalate crystal deposition.
Acidic macromolecules inhibit calcium oxalate nucleation, growth, aggregation and attachment to cells in vitro. To test for such an effect in vivo we used osmotic minipumps to continuously infuse several doses of the 5.1 kDa poly(acrylic acid) (pAA(5.1)) into rats fed a diet which causes renal calcium oxalate crystal deposition. Although kidneys of rats receiving the saline control contained calcium oxalate crystals, measured by polarized light microscopy, those of animals given pAA(5.1) had significantly lower numbers of crystals in various zones of the kidney. Delivery of pAA(5.1) to urine was confirmed by measuring excretion of infused biotinylated pAA(5.1). Both the derivatized and unlabelled pAA(5.1) had the same effects on crystallization in vitro. Our study shows that acidic polymers hold promise as effective therapies for kidney stones likely through prevention of calcium oxalate crystal aggregate formation.
Division of Nephrology, Department of Medicine, Medical College of Wisconsin and the Department of Veterans Affairs Medical Center, Milwaukee, Wisconsin 53295, USA. Kleinman@mcw.edu
Jack G
JG
Kleinman
Laura J
LJ
Alatalo
Ann M
AM
Beshensky
Jeffrey A
JA
Wesson
D000180:Acrylic Resins / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D000818:Animals; D002129:Calcium Oxalate / Q000378:metabolism*; D003460:Crystallization; D007669:Kidney Calculi / Q000188:drug therapy / Q000517:prevention & control*; D008297:Male; D000071228:Polyelectrolytes; D011108:Polymers / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014556:Urine / Q000737:chemistry
D000180:Acrylic Resins; D002129:Calcium Oxalate; D000071228:Polyelectrolytes; D011108:Polymers; C006903:carbopol 940