Twenty-eight-day oral toxicity study of lycopene from recombinant Escherichia coli in rats.

Lycopene produced by recombinant Escherichia coli was tested for subacute oral toxicity to determine its No-Observed-Adverse-Effect Level (NOAEL). Doses of 0, 200, 500 and 2000 mg/kg body weight/day were administered daily by gavage to 10 rats/sex/group for 28 days. No statistically significant, dose-related effect on body weight gain, clinical signs or ophthalmoscopic parameters was observed in any treatment group.

Recovery of injured adrenal medulla by differentiation of pre-existing undifferentiated chromaffin cells.

We described previous that the adrenal medulla recovers rapidly from the injuries due to salinomycin. In the present study we found the recovery to be apparently due to differentiation of pre-existing, primitive undifferentiated, chromaffin cells, rather than mitosis, as evidenced by lack of incorporation of 5-bromo-2-deoxyuridine in the differentiating and/or differentiated chromaffin cells. Electron-dense, striated fibrils observed within the necrotic cells and in the extracellular space were presumed to be intermediate degradation products.