Comparative effects of semisynthetic D-5-vinyl-2-thiooxazolidone and water-extracted rapeseed meal in the rat.
The toxic effect of two levels of semisynthetic D-5-vinyl-2-thiooxazolidone (VTO) (0.006 and 0.0012%) was compared in rats with that of 0.005% of the same substance present in 'detoxified' rapeseed meal (DRSM). Diets containing 10% protein as casein (control group) or DRSM were tested. Growth rates and protein efficiency ratio with DRSM were slightly less than in the controls. VTO did not affect the growth rate and seems to increase the protein efficiency ratio. Liver and thyroid weights were normal in rats fed DRSM. VTO increased liver weight independently of the concentration in the diet. The The effect on thyroid weight was proportional to VTO concentration, and the glands reached weights twice or three times that of normal. Both levels of semisynthetic VTO led to damage of the hepatic parenchyma. Liver weight was increased. Animals receiving DRSM did not show differences either in liver weight or histology compared to the controls. Thyroid histology of animals fed VTO or DRSM showed smaller follicles lined by tall cells and reduction of lumenal colloid. These changes were more severe in animals fed VTO. It is postulated that both VTO and isothiocyanate may decrease thyroid hormone production which in turn stimulates TRH and TSH release leading to glandular hyperplasia and hypertrophy.
D000818:Animals; D001937:Brassica; D004032:Diet; D005260:Female; D008099:Liver / Q000648:ultrastructure*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010080:Oxazoles / Q000633:toxicity*; D023303:Oxazolidinones; D010940:Plant Proteins / Q000633:toxicity*; D051381:Rats; D013961:Thyroid Gland / Q000648:ultrastructure*
D010080:Oxazoles; D023303:Oxazolidinones; D010940:Plant Proteins; C004333:goitrin