The effects of high dietary levels of sodium saccharin on mineral and water balance and related parameters in rats

The effects of sodium saccharin (NaS) treatment on mineral and water balance and a number of related parameters were studied over a 10-day period in rats. Treatment-related effects were observed in most study parameters. In addition, a number of differences between male and female rats in baseline values and/or in response to NaS administration were observed. With increasing dietary levels of NaS body weights decreased, but there were increases in water consumption, faecal water content, and caecal weights. NaS treatment resulted in increased urine volume and decreased urine osmolality, changes in urine mineral concentrations and increases in fresh and dry bladder weights, bladder-tissue hydration, and mineral concentrations in bladder tissue. The pattern and the dietary concentrations at which a number of these changes occurred in the bladder tissue suggest that increased urine volume and/or some property of the urine plays an important role in the aetiology of the bladder tumours that have been observed in rats fed high dietary concentrations of NaS. The evolution of the study parameters in rats with and without in utero exposure indicated that in utero exposure does not play an important role in the occurrence or severity of these changes.