Factors contributing to the deposition of oxalate in the heart in chronic renal failure

Abstract

The present study was undertaken in rats to clarify factors contributing to the myocardial deposition of calcium oxalate in chronic renal failure. A simple increase in plasma oxalate levels produced by injection of sodium oxalate did not cause deposits in the heart, nor did increased levels of plasma ionized calcium appear to be important. However, the absence of renal mass (bilateral nephrectomy) caused a minimal degree of oxalate deposition in many organs including the heart, lasting for only two days. The kidney may be likened to a selective sponge that accommodates most of the crystalized oxalate. Bilateral nephrectomy could therefore lead to precipitous oxalate crystallization in other tissues. Although oxalate deposits were hardly seen in the rat's own healthy heart, following heterotropic cardiac transplantation a much larger deposition of crystals was identified in the heart allograft which was histologically damaged by rejection. This finding suggests that the state of local tissue is a much more important factor in the deposition of oxalate crystals.