Regulatory toxicology and pharmacology : RTP
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Regul. Toxicol. Pharmacol. · Oct 1996
Disposition of 14C-erythritol in germfree and conventional rats.
The metabolism and disposition of U-14C-erythritol was examined in four groups of three male and three female, nonfasted rats each. The rats of groups A and D were germfree; the rats of groups B and C were kept under conventional conditions. The rats of group B received an erythritol-supplemented diet for 3 weeks prior to the experiment (adapted rats). ⋯ It is concluded that ingested erythritol is efficiently absorbed mainly from the small intestine, is not metabolized to a relevant extent in the body, and is excreted unchanged in the urine. The fraction of erythritol not absorbed is fermented by the gut microflora to intermediate products which are largely absorbed and metabolized. The data support a proposed physiological energy value for erythritol of about 0.5 kcal/g.
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Regul. Toxicol. Pharmacol. · Oct 1996
Subchronic oral toxicity studies with erythritol in mice and rats.
Erythritol is a sugar alcohol (polyol) with potential applications as a low-calorie, bulk sweetener. Ingested erythritol is efficiently absorbed and excreted unchanged via the urine since it is not metabolized systemically by the animal or human body. Erythritol was administered to four groups of 10 male and 10 female Swiss CD-1 mice and four groups of 15 male Wistar Crl:(WI) WU BR rats at dietary levels of 0, 5, 10, or 20% for 90 days. ⋯ In conclusion, the ingestion of erythritol for 90 days at dietary levels of up to 20% did not produce signs of toxicity in mice or rats. In particular, the morphological integrity of the kidneys was not adversely affected by the treatment in either species. The increases in urinary excretion of protein, GGT, NAG, and electrolytes were considered to result from extensive osmotic diuresis and a potential overload of the renal excretory system at the high dose levels employed.
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Erythritol was orally administered to Wistar rats at dietary levels of 0, 5, and 10% for 4 weeks. Soft stools and diarrhea were observed in male and female animals of the 10% group and in female animals of the 5% group. These symptoms disappeared during the course of the study. ⋯ No treatment-related histological changes were observed. No ill effects, other than early diarrhea, were observed from erythritol levels at 5 or 10% in the diet. Based on these results, it was concluded that the feeding of erythritol at a dietary level of 10% did not result in toxicologically significant effects.
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Regul. Toxicol. Pharmacol. · Aug 1996
On the use of scaling factors to improve interspecies extrapolation of acute toxicity in birds.
In avian toxicology, it is customary to extrapolate between species on the basis of acute toxicity measurements expressed in mg/kg body weight. Recently, it has been suggested that extrapolations should be on the basis of weight raised to the 0.6-0.7 power because there is good empirical evidence that, for mammals, this produces the best agreement between species. ⋯ With a subset of 37 pesticides of varying structures but heavily weighted to cholinesterase inhibitors, we found that the appropriate scaling factor in birds is usually higher than 1 and can be as high as 1.55. Extrapolations on the basis of weight alone or, worse, the use of inappropriate mammalian scaling factors could lead to serious underprotection of small-bodied bird species modeled in the course of risk assessment procedures.