Effects of rubratoxin B on liver composition and metabolism in the mouse

A single dose of rubratoxin B (0.67 mg/kg, ip) in propylene glycol caused a transient inhibition of leucine incorporation into liver proteins of 20–30 g male mice of the Swiss-Webster strain. This 12-hr suppression was followed by a stimulation of hepatic protein synthesis that persisted for 2 days after dosing. If there was any effect of the rubratoxin initially, it was partially or completely hidden by the comparable effect of the solvent. The highest doses (1.67 mg/kg and 2.67 mg/kg) caused decreases in total glycogen and protein. There was an increase after 24 hr in total liver lipids, principally in the triglycerides, at the highest dose (2.67 mg/kg) employed. Four consecutive daily ip administrations, totaling 0.67 mg/kg of rubratoxin B, resulted in a suppression of animal growth and lowering of food intake: however, liver composition was not altered significantly. No differences were detected in biochemical parameters between animals receiving rubratoxin B ip or po. Considerably greater quantities of rubratoxin B were required orally, however, to produce effects comparable to those observed following ip injection.