The toxicity of sulphite. I. Long-term feeding and multigeneration studies in rats
article
The toxicity of sulphite was studied by feeding rats on diets containing 0-2% sodium metabisulphite (Na2S2O5) for periods up to 2 yr and over three generations. Undue losses of sulphite were reduced by storing the diets at -18°C prior to feeding. Thiamine deficiency due to destruction of this vitamin by sulphite was prevented by drastic enrichment of the diets with thiamine. During storage up to the time of consumption, the losses of sulphite from the diets containing Na2S2O5 at levels of 0·125, 0·25, 0·50, 1·0 and 2·0% averaged 22, 14, 12, 8 and 4·5%, respectively, while the decrease in thiamine was 2·7, 1·7, 8·3, 14·5 and 15·4%, respectively. The feeding of sulphite considerably decreased thiamine levels in the urine and liver, but the addition of 50 ppm thiamine to the diet prevented thiamine deficiency in rats at sulphite levels up to 2%. A level of 2% sulphite caused slight growth retardation in F1- and F2-generation rats both before and after weaning. Occult blood was present in the faeces in groups given 1% sulphite or more. Relative weights of the kidneys were increased by the 2% sulphite level in the F2-generation females only, but this increase was accompanied by neither functional nor histological changes. Pathological examination revealed hyperplastic changes in both the fore- and glandular stomach with levels of 1 and 2% sulphite in each of the three generations. Some slight alterations were found also with 0·5% in the stomach of the F2-generation rats. There was no indication that sulphite had any carcinogenic effect. In studies on high sulphite levels (0-8%) for 10-56 days, diets containing 6% sulphite caused considerable growth depression and reduced food intake and food efficiency. Anaemia occurred at 2% and above, while the leucocyte count was slightly increased at 6%. Splenomegaly accompanied by a pronounced splenic haematopoiesis occurred with levels of 4% and above. In the forestomach, hyperplastic changes were found with 1% sulphite or more, while ulcers and papillomatous elevations occurred with 6 and 8%. In the glandular stomach, hyperplastic glands, haemorrhagic erosions, necrosis and inflammatory changes were observed with 4, 6 and 8% sulphite. The effects of sulphite on growth, food intake, food efficiency, the blood picture, spleen and stomach pathology and the presence of blood in the faeces were reversible. The dietary level of sulphite showing no untoward effect in rats was 0·25 or 0·215% Na2S2O5 (equivalent to 72 mg SO2/kg body weight/day) taking the loss of sulphite from the diet into account. © 1972 Pergamon Press Limited.
Chemicals/CAS: sodium, 7440-23-5; sulfite, 14265-45-3; thiamine, 59-43-8, 67-03-8; Sodium, 7440-23-5; Sulfites; Thiamine, 59-43-8
Chemicals/CAS: sodium, 7440-23-5; sulfite, 14265-45-3; thiamine, 59-43-8, 67-03-8; Sodium, 7440-23-5; Sulfites; Thiamine, 59-43-8
Topics
sodiumsulfitedrug effectfecesfeeding behaviorfemalefreezinghematopoiesisiatrogenic diseasephysiologysplenomegalystomachstomach ulcertimeAnemiaAnimalDietFecesFeeding BehaviorFemaleGrowthHematopoiesisInflammationKidneyLeukocyte CountMalePapillomaRatsRefrigerationSodiumSpleenSplenomegalyStomachStomach UlcerSulfitesThiamineThiamine DeficiencyTime FactorsUrine
TNO Identifier
227380
ISSN
00156264
Source
Food and Cosmetics Toxicology, 10(3), pp. 291-310.
Pages
291-310
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