W. G. JAFFE Y CRISTINA MONDRAGON
Instituto Nacional de Nutrición, Apartado 2049, Caracas, Venezuela
(Received 16 May 1974 – Accepted 17 June 1974)
- Rats were given moderate-selenium (4·5 mgfkg) or low-Se (0·5 mgfkg) diets during gestation and lactation. Their young were given diets with high (10 mgfkg), moderate or low Se contents from weaning, and groups of rats were killed at intervals during the 14-week experimental period.
- Compared with young rats which received the low-Se diet, those which received the moderate- or high-Se diets had a high incidence ofliver lesions and there were changes in liver Se content, haemoglobin concentration, packed cell volume, prothrombin activity, fibrinogen content, spleen weight, body water and serum glutamic-oxaloacetic and glutamic-pyruvic transaminase (L-aspartate: 2-oxoglutarate aminotransferase; EC 2.6. 1. 1 and L-alanine: 2-oxoglutarate aminotransferase; EC 2.6. 1.2 respectively) and alkaline phosphatase (EC 3. 1.3 . 1) activities. In those rats which received the high-Se diet the changes were more pronounced than in those which received the moderate-Se diet.
- In young rats from dams given moderate-Se diets, which were themselves given the moderate-Se diet, the liver Se content decreased continuously, whereas rats given the same diet but from dams which had received the low-Se diet, the liver Se content increased continuously. There was a slight improvement of symptoms of Se toxicity in all groups by the 5th week of the experimental period
- The results suggest that there was an adaptation to chronic Se intake.
The study of the prolonged action of selenium is of special interest in view of the fact that animals and humans living in seleniferous areas may be exposed to the effects of Se throughout their lives and for generations. Most of the long-term studies of Se toxicity have involved the use of inorganic salts of Se, although there are wellrecognized differences between their effects and those due to organic forms of the element, e.g. those found in food products and animal foods (Smith & Lillie, 1940).
Although there are numerous publications about the toxic effects of Se in animals (Rosenfeld & Beath, 1964), our knowledge of the physiological and pathological changes which occur in chronic selenosis is still incomplete.
In previous experiments, we found indications of an adaptation to moderate doses of Se (Jaffé & Mondragón, 1969). We have also reported (Jaffé, Mondragón, Layrisse & Ojeda, 1972), that the administration of organic Se to rats over a period of 6 weeks produced changes in the activities of some serum enzymes as well as in other blood factors. We suggested that the variations in these activities might be useful for the diagnosis of human selenosis.
In the present paper we report on the changes in activity of serum enzymes and some other indices of selenosis in young rats from dams given moderate-Se or low-Se diets.