The influence of hormones on cell division. I. Time-response of ear, seminal vesicle, coagulating gland and ventral prostate of castrate male mice to a single injection of estradiol benzoate.

THE mitogenic actions of hormonal materials have been studied in a variety of tissues belonging to the endocrine system proper or to its “target tissues”. The results of many such studies have been tabulated by Eigsti and Dustin [ 141. Estrogens and androgens have been demonstrated to be powerful mitotic stimulators of both the stromal tissues and epithelia of such glands as the seminal vesicle and ventral prostate [I 1, 231. Bullough and van Oordt [lo] have demonstrated that these materials are capable of inducing elevated levels of mitotic activity in the malpighian layer (stratum germinativum) of mouse ear epidermis. Dirschel, Zilliken and Dropp [13], in dose-response studies, have shown that a linear relationship exists between dose level and mitotic activity in mouse seminal vesicle when androgens are employed. Estrogenic materials, however, do not yield simple linear curves in this type of experiment. Experiments have been carried out to determine which hormonal factors may act to inhibit mitotic activity. Green and Ghadially [16] have demonstrated inhibition of mitosis in rodent skin following administration of cortisone. Bullough [5] has presented provocative data derived from in vitro studies on the effects of estrogen on mitotic activity of ear epidermis which tends to indicate that this material exerts its influence on cell division by intervention in the glycolytic phases of carbohydrate metabolism. In spite of the research effort which has been expended upon the problem of control of mitotic activity by hormonal materials, no clear picture of the points of hormonal interposition or of the hormonal interrelationships involved has as yet emerged. Much of the work concerned with the influence of hormones upon cell division has had as its goal the simple demonstration of the fact that a particular hormone is capable of inducing mitotic activity in a given tissue [22]. Data are often presented in relative terms such as the number of mitotic