Safety evaluation of yeast grown on hydrocarbons. IV. Two year feeding and multigeneration study in rats with yeast grown on pure n paraffins
article
Yeast grown on pure n-paraffins was fed at dietary levels of 10, 20 or 30'~ to groups of
30 male and 30 female rats in a 2-yr study and to groups of ten male and 20 female rats in a
reproduction study over three generations. Each study included two control groups, one on feed similar
to the yeast diets but with soya-bean meal substituted for the yeast, and the other on the Institute's
stock diet. In the 2-yr study, the feeding of the yeast had no adverse effect on mortality, rate of
body-weight gain, haematology, urine composition or kidney-function tests. The activities of glutamicoxalacetic transaminase and alkaline phosphatase in the serum of yeast-fed rats were relatively high but within the normal range. The feeding of the yeast did not affect the incidence or severity of
histopathological changes nor the type and incidence of tumours. The multigeneration study revealed
no effects on fertility, the number of young or the growth and mortality of the young during lactation.
In a 90-day study on rats from the third generation, no changes attributable to yeast-feeding were
apparent in any of the parameters investigated. It was concluded that the type of yeast examined
did not exert a harmful effect in rats at dietary levels up to 30%. Chemicals/CAS: Alkanes; Enzymes
30 male and 30 female rats in a 2-yr study and to groups of ten male and 20 female rats in a
reproduction study over three generations. Each study included two control groups, one on feed similar
to the yeast diets but with soya-bean meal substituted for the yeast, and the other on the Institute's
stock diet. In the 2-yr study, the feeding of the yeast had no adverse effect on mortality, rate of
body-weight gain, haematology, urine composition or kidney-function tests. The activities of glutamicoxalacetic transaminase and alkaline phosphatase in the serum of yeast-fed rats were relatively high but within the normal range. The feeding of the yeast did not affect the incidence or severity of
histopathological changes nor the type and incidence of tumours. The multigeneration study revealed
no effects on fertility, the number of young or the growth and mortality of the young during lactation.
In a 90-day study on rats from the third generation, no changes attributable to yeast-feeding were
apparent in any of the parameters investigated. It was concluded that the type of yeast examined
did not exert a harmful effect in rats at dietary levels up to 30%. Chemicals/CAS: Alkanes; Enzymes
Topics
TNO Identifier
227902
ISSN
00156264
Source
Food and Cosmetics Toxicology, 13(6), pp. 619-627.
Pages
619-627
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