RESUMO
Liver extract, plasma from intact mice, ES2 tumour extract and plasma from tumour bearing mice has an inhibiting effect on the mitotic activity of hepatocytes and duodenal enterocytes. In the present experiments, the effect of these treatments on the mitotic activity of renal tubular cells was studied. C3HS 28 day-old male mice, standardized for periodicity analysis were used. The determination of normal mitotic circadian curve of the renocytes was done. A second batch of mice were injected with 0.01 ml/gr of either liver extract, plasma from intact mice, ES2 tumour extract or plasma from tumour bearing mice, at 16:00 hours and controlled at 08:00, 12:00 and 16:00 hs during 2 consecutive days post treatment. Colchicine (2 micrograms/gr) was injected 4 hours before killing. Kidneys were processed for histology and mitotic index determinations. Results were expressed as colchicine metaphases per 1000 nuclei, and showed that mitotic activity values of treated animals were significantly lower than those of controls. In conclusion, mitotic activity inhibition of renocytes may be due to some non specific plasmatic and/or tissue factors.