The experimental development of the mammary gland with special reference to the interaction of the pituitary and ovarian hormones

Publication authorized May 13, 1948.Digitized 2007 AES.Includes bibliographical references (pages 41-48)

Studies of the adrenal cortex

PART I. The development of an assay method for ACTH based on its inhibiting effect on the formation of granulation tissue, and examination of the physiological factors affecting the response of experimental wound healing to ACTH.PART II. Adrenal function in guinea pigs with particular reference to scurvy.1). Adrenocorticotrophic hormone inhibits the formation of granulation tissue in mice, and this fact has been used as the basis of an assay in which a quantal response is measured. Potencies by this method and that of Sayers, Sayers and Woodbury (1948) are in close agreement.2). Physiological factors affecting the response of experimental wound healing to ACTH have been investigated in mice.a). No gonadotrophic activity was detected in the sample of ACTH used, and pitressin tannate and chorionic gonadotrophin did not produce this effect.b). Hypophysectomised mice became progressively and rapidly less responsive to ACTH.c). The gonads were essential for inhibition in very young and in mature mice.d). Adrenalectomised mice at the beginning of the breeding season, adrenalectomised pregnant mice, and adrenalectomised mice pretreated with chorionic gonadotrophin showed inhibition of healing by ACTH. Adrenalectomised mice pretreated with follicle - stimulating hormone or pregnant mares' serum gonadotrophin_ were not inhibited.e). Cortisone acetate caused inhibition in intact and gonadectomised mice. Neither testosterone, oestriol nor oestradiol had any effect, but progesterone gave definite impairment under the conditions of the experiment.f). It is suggested that in mice the gonads are capable of responding to ACTH under the influence of luteinizing hormone.3). Cortisone does not inhibit healing in guinea pigs.4) . a)Guinea pigs placed on a scorbutic diet showed a gradual increase of varying extent in urinary 17- ketosteroid excretion. This reached a peak in the terminal phases. No increase occurred in the absence of the adrenals, but the increase was unaffected by castration.b). Daily administration of ACTH in acute scurvy failed to influence the fall in body weight or time of ultimate death.c). Daily administration of cortisone failed to influence the ultimate outcome of acute anC chronic scurvy. Cortisone prevented adrenal hypertrophy in scurvy, and in chronic (but not acute) scurvy it reduced the haemorrhagic manifestations.d). In animals maintained on a dose of ascorbic acid leading to chronic scurvy, cortisone stimulated new bone formation at the epiphyses.5). In the late stages of acute scurvy when adrenal ascorbic acid is minimal, there is still a normal response to exogenous ACTH as judged by a rise in urinary 17 -ketosteroid excretion, over and above that due to developing scurvy.6). Normal pregnant guinea pigs show a greater response to ACTH than non - pregnant ones. Urinary 17- ketosteroid excretion was not increased by gonadotrophin administration to castrated animals.7). It has been shown that dehydroascorbic acid (DHA) is antiscorbutic. DHA administration leads to the development of characteristic features, which include fatty degeneration of the liver, flexion of the fore and hind feet and partial hind -leg paresis.8). The dietary intake of adrenalectomised animals has been measured. The possible presence of an important dietary factor, other than ascorbic acid, in cabbage has been discussed

Sex differences for object location memory in rats : the contribution of the dentate gyrus

ix, 72 leaves : ill. ; 29 cmFemales exhibit superior object location memory (OLM) compared to males, but the reasons for this sex difference remains unknown. This thesis investigates the role of the dentate gyrus (DG) in an OLM task in normal rats (Experiment 1) and after bilateral adrenalectomy (ADX; Experiment 2). ADX is known to reduce volume of the DG and impair spatial learning. There was no sex difference for OLM in Experiment 1 but females exhibited superior OLM in Experiment 2. Experiment 2 found a significantly smaller DG due to ADX but this had no effect on behaviour. The male DG was significantly larger than the female DG in both experiments. Behaviour during the OLM task was not a predictor of DG volume, although a larger than average DG was related to poor OLM memory in females Thus, the DG involvement for OLM appears to differ between the sexes

Method of estimating thyroid hormone secretion rate of rats and factors affecting it

Digitized 2007 AES MoU.Includes bibliographical references (pages 53-58)

The in vitro metabolism of desoxycorticosterone and pregesterone by bovine corpus luteum.

Thesis (M.S.)--Boston Universit

Effects of chronic ACTH stimulation, gonadal hormones, thyroidal hormone treatment and age on adrenocortical function of the rat

Thesis (Ph.D.)--Michigan State University. Department of Physiology, 1970Includes bibliographical references (pages 153-165