The authors recently reported that occupational exposure to trimethyltin (TMT) is a risk factor for developing kidney stones. To further examine the association between TMT exposure and the formation of kidney stones, a 180-day animal study was conducted. The randomly grouped Sprague-Dawley (SD) rats were exposed to TMT in the drinking water at doses of 0, 8.2, 32.8 and 131.3µgkg(-1) day(-1) . Transient behavioural changes were observed in the high-dose group during the first 2 weeks of exposure. TMT exposure led to a significant dose-dependent inhibition of renal H(+) /K(+) -ATPase and an increase in urinary pH. In comparison to no kidney stones being identified in the control and the lowest dose group, 1 rat in the 32.8µgkg(-1) day(-1) dose group and 3 out of 9 rats in the 131.3µgkg(-1) day(-1) dose group were found to have stones in the kidney/urinary tract. Pathological analysis showed that more wide spread calcium disposition was observed in kidneys of rats with TMT exposure compared with the rats in the control group. However, X-ray diffraction (XRD) analysis found that the kidney stones were mainly composed of struvite with the formula: NH4MgPO4 6H2 O, while calcium-containing components were also detected. The authors concluded that together, this study further demonstrates through animal studies that chronic exposure to a relatively low level of TMT induces nephrotoxicity and increases the risk for developing kidney stones.
Authors: Ren X, Wu X, Sui G, Gong Z, Yawson E, Wu B, Lai G, Ruan X, Gao H, Zhou F, Su B, Olson JR, Tang X. ;Full Source: Journal of Applied Toxicology. 2014 Sep 16. doi: 10.1002/jat.3054. [Epub ahead of print] ;