Characteristics of the cell proliferation profile of activated rat hepaticstellate cells in vitro in contrast to their fibrogenesis activity

Purpose. Alterations in the kinetics of hepatic stellate cells (HSCs) after the cells are activated once have not been well documented. We investigate d the characteristic profiles of cell proliferation of once-activated HSCs in contrast to the in fibrogenesis activity. Methods, HSCs from male Wistar rats were submitted to primary culture for 14 days and to secondary cultur e for 7 days. The potential for cell proliferation was evaluated by the num ber of the cells in G2/M phase, based on flow cytometric analysis of the ce ll cycle. The fibrogenesis activity was assessed by Northern blot analysis of the expression of type I and type III procollagen mRNA. Results, The num ber of HSCs in G2/M phase was maintained at a low level in primary culture after 6 days, while a significantly (P < 0.05) elevated number of HSCs in G 2/M phase was observed on days 3 to 4. In secondary culture, the number of HSCs in G2/M phase was also consecutively maintained at a decreased level. By contrast, HSCs showed progressively increased type I and type III procol lagen mRNA expression during the experimental periods of primary culture. C onclusions, These results clearly demonstrated consecutively decreased prol iferative activity, evaluated by the potential for cell mitogenesis, in onc e-activated HSCs, in contrast to their progressively increased fibrogenesis activity.