EFFECT OF TISSUE AND PLASMA FACTORS ON KIDNEY PROLIFERATION

Liver extract, plasma from intact mice, ES2 tumour extract and plasma from tumour bearing mice has an inhibiting effect on the mitotic activ ity of hepatocytes and duodenal enterocytes. In the present experiment s, the effect of these treatments on the mitotic activity of renal tub ular cells was studied. C3HS 28 day-old male mice, standardized for pe riodicity analysis were used. The determination of normal mitotic circ adian curve of the renocytes was done. A second batch of mice were inj ected 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 hour s and controlled at 08:00, 12:00 and 16:00 hs during 2 consecutive day s post treatment. Colchicine (2 mu g/gr) was injected 4 hours before k illing. Kidneys were processed for histology and mitotic index determi nations. Results were expressed as colchicine metaphases per 1000 nucl ei, and showed that mitotic activity values of treated animals were si gnificantly lower than those of controls. In conclusion, mitotic activ ity inhibition of renocytes may be due to some non specific plasmatic and/or tissue factors.