Calcium oxalate-crystal membrane interactions: dependence on membrane lipid composition.

PURPOSE

Urolithiasis is clearly a multifaceted process, progressing from urine supersaturation to the formation of mature renal calculi. Retention of microcrystals by the urothelium is a critical event in stone maturation. Membrane phospholipids appear to be involved in the attachment of stone crystals to kidney epithelium.

MATERIALS AND METHODS

The current study quantitates crystal-membrane interactions following selective changes in the red blood cell (RBC) membrane phospholipid composition by using a crystal-induced membranolytic assay.

RESULTS

Membrane enrichment with anionic phospholipids was found to greatly increase crystal-membrane interactions. Crystal-membrane interaction was associated with an increase in the negative charge on the RBC membrane surface.

CONCLUSIONS

Specific membrane compositions seem to facilitate the formation of crystal attachment region on the RBC surface that is necessary for effective crystal attachment to the cell membrane.