The effect of oestrone on the metabolism of rat uterus.

IT has been established that injection of oestrogenic hormone causes an increase in the rate of metabolism of certain tissues. Thi's has been shown for uterus by several workers (for literature see Tesauro [1936]), for ovary by Kiyohara & Izawa [1936], for anterior pituitary and for liver by Victor & Andersen [1937], Andersen & Victor [1938]; the latter workers, as well as Kiyohara & Izawa, showed further that kidney tissue is unaffected by injection ofhormone. Another effect of injecting such hormones is to produce rapid growth of the uterus. This growth can be measured by observing either the increase in dry weight [Astwood, 1938; Varangot, 1939] or the number of cell divisions after injection of colchicine [Allen et al. 1937]. Both methods show that growth can first be observed 6-9 hr. after injection, and that it is maximal after 36 hr. The results to be reported here show that the changes in metabolic rate closely follow these growth changes, the first increase occurring from 6 to 12 hr. after injection, whilst the maximal rate is reached after 24-36 hr. During the subsequent regression period metabolic rate is depressed, the original rate being regained 96 hr. after injection, when the weight has returned to the pre-injection value [Varangot, 1939].