The present study is designed to elucidate certain biological characteristics of urinary chorionic gonadotropin and to see what differences could be demonstrated between HCG in normal pregnancy and in the trophoblastic diseases. We have attempted the biological characterization of HCG using crude HCG and the purified HCG (12, 000 I.U./mg) by zone electrophoresis on starch grain and chromatography on DEAE cellulose. Evidence has been presented that urinary HCG extracts are fractionated into two or more biologically active components. The one component has predominantly FSH activity and the other predominantly LH activity. Furthermore, our present investigation revealed possible differences between the gonadotropin in the urine from pregnant women and from patients with trophoblastic tumors.

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The secretory rates of progesterone and 20α-hydroxypregn-4-en-3-one (20α-OHP) from the ovary and the concentration of both progestins in the ovarian tissues were determined during the estrous cycle in 4-day cyclic rats illuminated 12 hrs. a day (8a.m. to 8 p.m.). The progesterone secretion increased twice a cycle, markedly on the evening (peak at 7p.m.) of the day of proestrus and slightly on the afternoon of the day of early diestrus. The prompt and tremendous increase of progesterone secretion at the preovulatory stage almost synchronized with the release of luteinizing hormone (LH). It was also demonstrated that a marked preovulatory rise of progesterone secretion depended upon pituitary LH discharge, and a slight increase in both progestin secretions-at early diestrus was not dependent on the pituitary function at that stage. These facts together with the following fmdings, (a) an enormous increase in the ratio of progesterone over total progestin (progesterone plus 20α-OH-P) in the ovarian venous blood at the preovulatory stage, (b) the secretory pattern of 20α-OH-P which roughly paralleled with that of progesterone at the diestrous phase, and (c) a higher concentration of progesterone in the ovary as compared with that of 20α-OH-P at the diestrous phase and its reverse relationship of the concentrations at the stages of proestrus and estrus, suggest that a drastic shift occurs at the sites of progesterone synthesis from the involuting corpora lutea to the LH sensitive ripening follicles or interstitial tissues under the influence of released LH which exerts both luteinizing effect and steroidogenic action on the ovary, and the present data suggest that the newly developed corpora lutea after ovulation gain the automaticity of progestin synthesis, storage and secretion independently of the pituitary function.

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The ovarian progesterone secretion markedly increased on the evening of the day of proestrus during the estrous cycle in rats. This increase was completely disappeared when the rats were hypophysectomized at 5.00p.m. on proestrus. Intravenous administration of pituitary extracts obtained from the rats at any stage of the estrous cycle was able to restore the increase in progesterone secretion in the rats hypophysectomized at 5.00p.m. on proestrus. Various gonadotropins and other pituitary hormones were examined to see their effects on ovarian progestin secretion in the hypophysectomized rats. Luteinizing hormone (LH) showed a strong stimulating action which was relatively long-lasting and its minimum effective dosage appeared to be 0.2 to 0.5μg per rat. A similar stimulatory effect was produced by follicular stimulating hormone (FSH), human chorionic gonadotropin (HCG), pregnant mare's serum gonadotropin (PMS), thyroid stimulating hormone (TSH), and growth /hormone (GH), but not by prolactin, adrenocorticotropin (ACTH), oxytocin, and vasopressin. The action of FSH was transient and its potency was only 1 to 2 per cent of the activity of LH. Taking account of a minute amount of LH which possibly contaminates the preparations of FSH, TSH and GH, it is suggested that a preovulatory increase of progesterone secretion is most likely caused by LH released from the pituitary into the circulating blood.

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A single subcutaneous injection of progesterone (3mg/rat) into 4-day cyclic rats at 11a.m. on the 2nd day of diestrus caused an approximately 48-hr. delay in ovulation. Estrogen administered 24 to 30hrs. after the progesterone treatment restored the delayed ovulation in approximately 24hrs. The minimal effective doses of various estrogens to cause a 24-hr. recovery of the progesterone-delayed ovulation were 0.2mg for estradiol-17β and estrone and 0.05mg for estriol, suggesting that LH releasing activities of estrogens are not related to their estrogenicity but to their metabolism in the liver. Estrogens administered 6hrs. after the progesterone treatment restored the ovulation completely, which was otherwise expected to delay by 48hrs. Hexestrol and mestranol (17α-ethinyl-3-methoxyestra-1, 3, 5 (10)-trien-17β-ol) also showed a similar effect, but they were less active than estradiol. The ovulation was advanced by 24hrs. when 10 or 20mg of progesterone was injected again 48 to 54hrs. after progesterone pretreatment, but it was not advanced by the administration 24hrs. after the pretreatment. The blood LH level always showed the peak at 7p.m. on the day before ovulation regardless of administration of ovarian steroid. It was concluded, therefore, that both estrogen and progesterone were able to provide a 24-hr. acceleration for the mechanism of LH release, but unable to produce an hourly change in the time of LH release. It is suggested, therefore, that in normal estrous cycle the estrogen started to secrete on the afternoon of the day before proestrus triggers somehow the initial discharge of LH at the critical time which has been fixed already by the neural mechanism of CNS under certain environmental factors, mainly lighting schedule, and that progesterone discharged under the influence of initial release of LH, in turn, facilitates the LH releasing mechanism in CNS to induce further release of LH, the amount of which is sufficient to cause ovulation.

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It was confirmed that estrogen secreted on the day before proestrus (diestrus II) is required for proestrous uterine distension, for ovulatory discharge of luteinizing hormone (LH) and for vaginal cornification in the rat. Further investigation was made to determine the timing of estrogen secretion responsible for LH release at the critical period on proestrus and for uterine and vaginal changes in the rats showing 4-day estrous cycle under the illuminating schedule of 12hrs. light (8a.m. to 8p.m.) a day. The rats were ovariectomized at varying times between diestrus II and proestrus, and autopsied at 7 p.m. on proestrus for the determination of LH concentration in the circulating blood. it was demonstrated that the ovary must be in situ between 4a.m. and 7a.m. at proestrus for the discharge of LH. In the same experiment, a complete uterine distension was observed at 7p.m. on proestrus only in the rats ovariectomized at 4a.m. or later in proestrus, but no uterine distension was obtained in the rats operated at 7p.m. or earlier in diestrus II. In the rats hypophysectomized at 1p.m. or earlier in diestrus II, vaginal cornification did not occur on the expected day of estrus, but did occur in all the rats hypophysectomized at 4p.m. on diestrus II. Anti-estrogen, MER-25, given at diestrus I (metestrus) at the dosage of 10mg per rat inhibited the appearance of proestrous smear, subsequent ovulation and vaginal cornification, while no inhibition of those were obtained when the compound was injected at diestrus II. It is suggested, therefore, that estrogen secreted at diestrus I is responsible for the proestrous change of vaginal smear which is a necessary step to the subsequent cornification; estrogen secreted till 1-4a.m. on proestrus accounts for uterine distension; and estrogen secreted till 4-7a.m. on proestrus is necessary for ovulatory discharge of LH.

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The effects of hypothyroidism for a short period of postnatal life on the induction of persistent estrus by androgen were investigated in female rats of 10 and 13 days of age. Hypothyroidal new born rats produced by feeding propyl thiouracil (PTU) to the mother rats, were more succeptible to the persistent-estrus inductive influence of androgen than normal and thyroxine-therapied hypothyroidal rats of the same age.It is concluded that the period during which androgen exerts a persistent-estrus inductive influence was prolonged in hypothyroidal rats, possibly as the result of the retardation of development of the hypothalamic region, the site affected primarily by androgen.

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Injection of a homogenate of the pituitary gland of bull frog tadpoles remarkably increased the tyrosinase activity in the skin of hypophysectomized toad tadpoles. The enhancement of the enzyme activity was blocked by the simultaneous treatment with actinomycin D (Act. D), indicating that the increase in activity by the homogenate is closely related to RNA synthesis.
Activation of the enzyme of the skin by the pituitary homogenate injection was greater in hypophysectomized tadpoles than in normal. When the hypophysectomized tadpoles were subjected temporarily to the influence of the pituitary in advance of the treatment with the pituitary homogenate, the activation of the enzyme the homogenate injection was reduced to a level observed in normal tadpoles, suggesting that some regulatory mechanisms concerning tyrosinase activity develop in skin during the embryonic period under the influence of pituitary hormones.

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The chromatographic separation of gonadotropin-inhibiting substance in the extract obtained from adult male urine according to the method of Johnsen was attempted on a Sephadex G-100 column. The ovulation assay was employed to detect the inhibitor in the fractions using female mice, 19-20 days old, which received PMS and HCG to obtain a minimum constant ovulation. In the chromatography of the extract, the inhibitor mainly emerged in the early fractions or in the excluded volume, while HPG appeared in the later fractions which induced super-ovulation when injected with the standard dose of HCG. A slight inhibition on the ovulation was observed in the far later fractions.

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Plasma Human Growth Hormone (HGH) levels were determined in 176 healthy school children, 74 monozygotic and 14 dizygotic twins of 13-to 18-year-old, and in 34 healthy adult subjects 4 hrs. after the test breakfast. There was a considerable variation in plasma HGH concentrations, but most samples showed the values of 0.25mμg/ml to 40mμg/ml. The wide distribution of plasma HGH was especially noted in 13-and 14-year-old subjects in both sexes. In the male subjects, a definite difference in the distribution was noted between the 13-to 14-year-old school children and the 16-year-old or older subjects. In the female subjects, the difference was not so noticeable as in the male subjects. No correlation was noted between the plasma HGH levels and physical size of the subjects, nor between the values of plasma HGH in individual twins.

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O, P'-DDD was given to a 41-year-old Japanese woman with metastatic adrenocortical carcinoma with dosage of 8g a day orally. The treatment resulted in objective regression of all metastases for 237 days. Significant decrease was seen in ketosteroid, 17-hydroxycorticosteroid, 17-ketogenic steroids, estrogen in the urine, 17-hydroxycorticosteroid, cortisol in plasma during the course of treatment.

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