No abstract

Tartrazine, amaranth and sunset yellow fed at concentrations of 0ṁ03, 0ṁ3, and 1ṁ5 per cent of the diet for 64 weeks, did not increase mortality in male or female rats. Amaranth, at a level of 1ṁ5 per cent, caused a significant decrease in growth rate in female, but not male, rats. This was attributed to an effect on food utilisation rather than on food consumption. Female rats fed amaranth at 0ṁ3 and 1ṁ5 per cent concentrations showed an increase in the weight of the liver. At the higher concentration there was also an increase in kidney weight. Histopathological studies were made on the lung, heart, liver, spleen, thyroid, pancreas, stomach, small intestine, kidney, urinary bladder, adrenal, testis, prostate, coagulating gland, ovary, uterus, and thymus. None of the changes observed were considered to be due to the ingestion of the food colours. There was no significant difference in tumour incidence between the control animals and the rats receiving the colours.

The wet weight of the sciatic nerve of the rat increased as the nerve degenerated after nerve section. At the same time the concentration of nucleic acid increased and the concentration of total phospholipid, sphingomyelin (phosphosphingoside), and free cholesterol decreased. Cholesterol ester, absent from intact nerves, appeared during the degeneration. These findings are in agreement with those previously reported for the sciatic nerve of the cat (3, 5), with the exception that all the changes took place more rapidly in the rat than in the cat. It would thus appear that the changes previously described for the cat are general in nature and not merely characteristic of one particular species. These experiments indicate that the rat is a suitable experimental animal for the study of the effect of dietary and other factors on Wallerian degeneration.

No abstract

The food colours Brilliant Blue FCF, Guinea Green B and Benzyl Violet 4B were fed to rats at concentrations of 0.03, 0.3 and 3 per cent of the diet for 75 weeks. Thirty rats were used at each feeding level. Brilliant Blue and Benzyl Violet had no adverse effects on growth at any of the levels used. With Guinea Green there was an initial depression of growth at the two higher levels accompanied by a decreased food efficiency and, in one group, a lower food consumption. There was an increase in mortality in female rats fed 3 per cent of all three colours. With Brilliant Blue, indications were that this increase was not related to treatment. In the groups fed 3 per cent Guinea Green and 3 per cent Benzyl Violet there was a total of eight malignant tumours. Five of these were derived from the epidermis. Further investigation of these two colours is required.