The influence of ovariectomy on the chemical composition of regenerating rat liver.

Because of the remarkable rate of restoration of liver tissue, the partially hepatectomized rat has been recognized as a useful preparation in which to study the process of active tissue growth (1-13) and the participation of various cellular components in this process (cf. (14)). However, the very early postoperative period, during which extreme fluctuations in liver constituents occur, has been almost uniformly neglected. Parallel studies of the various liver components have not been made in such a manner as to permit integration of the rates of restoration of lipide, protein, and water during early hepatic regeneration. In the present investigation, the nitrogen, water, and lipide content of the regenerating rat liver has been followed at frequent intervals during the first few days after partial hepatectomy. The results obtained have been correlated with the increase in size of the remaining liver and with the onset of true growth as indicated by mitotic activity. In addition, the role of ovarian secretions in the mobilization of these liver constituents has been investigated.