PLoS ONE (Jan 2013)

Monosodium glutamate (MSG) consumption is associated with urolithiasis and urinary tract obstruction in rats.

  • Amod Sharma,
  • Vitoon Prasongwattana,
  • Ubon Cha'on,
  • Carlo Selmi,
  • Wiphawi Hipkaeo,
  • Piyanard Boonnate,
  • Supattra Pethlert,
  • Tanin Titipungul,
  • Piyapharom Intarawichian,
  • Sakda Waraasawapati,
  • Anucha Puapiroj,
  • Visith Sitprija,
  • Sirirat Reungjui

DOI
https://doi.org/10.1371/journal.pone.0075546
Journal volume & issue
Vol. 8, no. 9
p. e75546

Abstract

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BackgroundThe peritoneal injection of monosodium glutamate (MSG) can induce kidney injury in adult rats but the effects of long-term oral intake have not been determined.MethodsWe investigated the kidney histology and function in adult male Wistar rats that were fed ad libitum with a standard rat chow pellet and water with or without the addition of 2 mg/g body weight MSG/day in drinking water (n=10 per group). Both MSG-treated and control animals were sacrificed after 9 months when renal function parameters, blood and urine electrolytes, and tissue histopathology were determined.ResultsMSG-treated rats were more prone to kidney stone formation, as represented by the alkaline urine and significantly higher activity product of calcium phosphate. Accordingly, 3/10 MSG-treated rats developed kidney stones over 9 months versus none of the control animals. Further, 2/10 MSG-treated rats but none (0/10) of the controls manifested hydronephrosis. MSG-treated rats had significantly higher levels of serum creatinine and potassium including urine output volume, urinary excretion sodium and citrate compared to controls. In contrast, MSG-treated rats had significantly lower ammonium and magnesium urinary excretion.ConclusionOral MSG consumption appears to cause alkaline urine and may increase the risks of kidney stones with hydronephrosis in rats. Similar effects in humans must be verified by dedicated studies.