Co-contamination, but not mammalian cell conversion of melamine to cyanuric acid the likely cause of melamine-cyanurate nephrolithiasis.

摘要

Melamine, a nitrogen rich industrial chemical used for manufacturing durable crockery, whiteboards, furniture, etc, has also been investigated as nitrogen source for farm animals, but found inferior to urea and cottonseed [1]. Recently, unscrupulous individuals in China added the chemical to wheat gluten (processed into pet foods) and milk to surreptitiously boost the "protein" content, with dire consequences. Countless pets in America and six infants out of 300,000 children fed tainted food in China have died, primarily from kidney failure [2]. While melamine is relatively non-toxic and 90% is excreted in urine within 24 h [2], the kidney damage results from melamine-cyanurate calculi deposited in distal nephrons. Melamine per se failed to form renal calculi in experimental animals; and neither did its counterpart - cyanuric acid (CA). Nephrolithiasis only occurred when melamine and CA were co-administered to animals [3,4].