Ovarian follicles of 5 to 15mm in diameter were isolated from 45 ovaries of 34 patients in the follicular and luteal phases of the cycle. Three experiments were done. In the first, follicles were minced and incubated in Krebs-Ringer bicarbonate buffer containing 1 to 21μCi of testosterone-4-¹⁴C in the presence or absence of 100 IU human chorionic gonadotropin (hCG). In the second, minced follicles were incubated with 100μCi of sodium acetate-1-¹⁴C under identical conditions. In the third, ten follicles from a single patient in the late proliferative stage of endometrial dating were cut in halves and incubated with 100 μCi of acetate-1-¹⁴C under identical conditions. The minced follicle preparation was capable of aromatizing testosterone-4-¹⁴C into radioactive estrone and estradiol in significant amounts. Incorporation of radioactive acetate into pregnenolone, progesterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, testosterone, estradiol and estrone was assessed by reverse dilution analysis with recrystallization to constant specific activity. The major radioactive products formed were androstenedione and 17-hydroxyprogesterone in the latter two experiments. Dehydroepiandrosterone was one of the major steroids in the second experiment. The minor products were testosterone, progesterone and pregnenolone. Smaller, but definite incorporations of radioactive acetate into estradiol and estrone occurred in the second experiment. On histological examination, the follicles were characterized by atretic changes. This distribution pattern of radioactive acetate among the steroids was considered to represent the steroidogenic profile of unstimulated or atretic follicles.

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The development of 1, 25-(OH) ₂D₃ receptor in the duodenal cytosol of chick embryo was studied by the sucrose density gradient analysis.
The binding profile for 1, 25-(OH) ₂D₃ in the cytosol of vitamin D-deficient chick duodenum on the sucrose density gradient revealed 3 binding components, and the sedimentation constant was estimated as 2.5, 3.5 and 5.5S respectively. The 3.5S binding component has high affinity and low capacity for 1, 25-(OH) ₂D₃ and is thought to be 1, 25-(OH) ₂D₃ receptor.
During the development of chick embryo, the 3.5S binding component was not detected in 13-day embryonic duodenum, it appeared on 15th day of incubation and then gradually increased to the level of vitamin D-deficient chick on 19th day of incubation.
The 5.5S binding component was specific for 25-OH-D₃ and it was found even in 13-day embryo, but it did not show any significant change during development. On the other hand, the 2.5S component was not specific for either 1, 25-(OH) ₂D₃ or 25-OH-D₃. However, it was main binding component in early stages of development and decreased during development.
From these results, it is suggested that the receptor for 1, 25-(OH) ₂D₃ is available a few days before hatching and the inability to produce CaBP in the duodenum of chick embryo could not be ascribed to the absence of the receptor.

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The pituitary functions were tested in two males with the typical clinical pictures of hypogonadism. The secretions of ACTH, TSH, GH and prolactin in these patients were maintained within normal limits, whereas they had markedly diminished LH and FSH levels in plasma. Plasma LH and FSH responses to the intravenous injection of 100μg LH-RH were absent or limited. After 7-day treatment with intravenous infusion of 400μg LH-RH, they showed normal or improved responses to the intravenous injection of 100μg LH-RH. Thus, the diagnosis of isolated gonadotropin deficiency due to a hypothalamic lesion was established. Initially, the standard LH-RH test (100μg intravenous injection) did not elicit a rise in plasma GH levels. However, it was of interest that after the repeated stimulation by 400μg LH-RH, GH response to the intravenous injection of 100μg LH-RH was observed in both patients.

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The intracellular localization of ³H-estradiol-17 (3 and ³H-progesterone to the different types of cells in the mouse uterus was investigated using autoradiographic techniques). The kinetics of cell proliferation in the surface epithelium of the uterus and in the vaginal epithelium (basal layer) are analysed by means of cumulative labelin gmethod and mitosis chase method using ³H-thymidine autoradiographic procedures. The results are as follows.(1) Epithelial cell population of the uterine lumen and basal cell population of the vaginal epithelium in the ovariectomized mouse are divided into a major subpopulation of Go cells and a minor subpopulation of proliferating cells.(2) Proliferative potencies of uterine surface epithelial cells and vaginal basal cells in the ovariectomized mouse are regulated by a steroid-independent mechanisms through which the proportion of the G₀ cell-compartment and Tc value of the proliferating cell-compartment are determined according to their age; as the castrated mouse grows older, Tc value becomes longer and the proportion of the G₀ cellcompartment becomes larger.(3) If the dose levels of estrogen administered exceed the threshold value, estrogen-dependent cell proliferation will be provoked by transferring the cells in the G₀ cell-compartment to the proliferating cell-compartment in all or none fashion, and by reducing the Tc value of proliferating cell to 1/2-1/3 of that in the castrated mouse.(4) It is suggested that proliferating cells in the uterine surface epithelium and in the vaginal epithelium turn the cell cycle at a constant Tc value during estrous cycle, and that the tissue growth during estrous cycle is dependent on the size of the proliferating cell-compartment but not on the Tc value.(5) The results obtained from autoradiography of tritiated steroids in the mouse uterus gave a supporting clue to the kinetic data.

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Resting cells (G₀ cells) of the uterine surface epithelium in castrated mice began to synthesize DNA with high synchrony from 10hr after the injection of 50ng of estradiol-17β with or without 5.5μg of clomiphene citrate. Highly synchronized DNA synthesis in G₀ cells elicited with estradiol was delayed approximately 5hr when the simultaneous administration of 0.5mg of progesterone was given. In Go cells of castrated mice which received 5.5μg of clomiphene or 55μg of clomiphene plus 50 ng of estradiol, DNA synthesis with partial synchrony began 15hr after the injection. The effects of estradiol were completely suppressed by the administration of 55μg of clomiphene. It is suggested that the inhibitory action of clomiphene may be due to the competitive blocking of estrogen binding, while progesterone suppresses the estrogen-induced DNA synthesis of the surface epithelium and transfers them to the G₀ cell-compartment.

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The effects of mannoheptulose and DL-glyceraldehyde on glucose-induced insulin release and cyclic AMP levels in islets isolated from rat pancreas were investigated. Mannoheptulose inhibition on glucose-induced insulin release was observed after only 5-min incubation period, indicating an inhibitory effect on the early phase of insulin release. This inhibition on insulin release was accompanied with the simultaneous depression of cyclic AMP levels in islets. By the addition of DL-glyceraldehyde to the medium in which glucose and mannoheptulose were present, the depressed cyclic AMP levels in islets were recovered to the control level completely but the restoration of insulin release in the early phase was not complete. In the absence of glucose, DL-glyceraldehyde did not demonstrate a significant increase of insulin release during 5 min incubation, though a marked stimulation was observed after 30-min incubation. Cyclic AMP levels in islets were not affected by DL-glyceraldehyde. When DLglyceraldehyde was added to the medium with glucose, significant inhibition of glucoseinduced insulin release in its early phase was observed without the reduction of cyclic AMP levels in islets
From these findings, the following possibilities are suggested and discussed. 1. Maintenance of the cyclic AMP levels in islets is a necessary but insufficient condition for glucose-induced insulin release particularly for its early phase. 2. Glucose-induced insulin release seems to depend on both the binding of glucose with glucoreceptor and the supply of some metabolites. Mannoheptulose inhibits both mechanisms. DL-glyceraldehyde may supply metabolites but competitively inhibit the binding of glucose to the glucoreceptor.

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The time course of hypothalamic corticotropin-releasing factor (CRF) activity after the administration of ether stress was different from that after immobilization stress. The maximal response of CRF activity was observed 2min after ether stress, followed by a precipitous decrease 5min after the stress. A gradual increase of CRF activity was subsequently observed for several minutes with fluctuated changes. Thus, response pattern was vibratory. But under immobilization stress, markedly fluctuant changes of CRF activity seen in the case of ether stress did not appear after the maximal response observed at 2 min, indicating that the response pattern was not vibratory. On the other hand, the concentration of plasma corticosterone increased significantly 5min after the ether or immobilization stress with the peak value around 17min.

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Twenty-four-hr patterns of plasma corticosterone levels were determined at 4-hr intervals every 3-4 weeks in sighted and blinded pinealectomized rats of adult age. Through the whole period of the experiment, 24-hr patterns of food intake were also measured weekly.
The sighted rats manifested the same 24-hr patterns of plasma corticosterone levels and food intake for 15 weeks after pinealectomy as those observed in the intact control rats. The magnitude of peak levels of plasma corticosterone and the amount of food intake did not differ between the two groups.
A phase shift in circadian rhythms of plasma corticosterone levels and food intake was observed in both groups of blinded rats, with and without pinealectomy. Between the two groups, the patterns of phase shift were essentially similar for 10 weeks examined after optic enucleation. The peak elevation of plasma levels took place at 11p.m. at the end of the 4th week after optic enucleation. Thereafter, 4-to 8-hr delay of peak appearance was observed every 3 weeks. No significant differences were found in peak values between the two groups of blinded rats. Furthermore, the circadian rhythm of food intake shifted in parallel with that of plasma corticosterone levels. A phase reversal of these two activities was observed between the 8th and 10th week after the operation.
These results indicate that the pineal gland does not play any important role either in the maintainance of normal circadian periodicities of adrenocortical activity and food intake or in the shift in circadian rhythms of the two activities in the blinded rats.

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Endocrine functions were investigated in a case of “β-adrenergic hyperdynamic circulatory state”. This state was diagnosed by (1) typical symptoms of cardiac awareness, (2) physical findings (increments of pulse rate and blood pressure by changing positions or walking), (3) increase in cardiac output (5.25l/min→14.03l/min) and decrease in circulatory time (10.8 sec→45.5sec) by isoproterenol infusion (0.02μg/min/kg body weight), (4) rapid loss of symptoms and above findings by propranolol treatment (30mg per os daily) and reappearence by discontinuing medication.
The mechanism of insulin response to glucose has been a controversy as to whether the secretion is transmitted by β-receptor or independent glucose receptor. And in this physiologic β-adrenergic state, it was found that insulin responses in IVGTT and OGTT were within normal limit. When β-adrenergic condition was corrected by propranolol treatment, insulin responses were shown lowered, though in the normal range. This could be reproduced by discontinuing medication. Insulin, glucagon and growth hormone secretions caused by arginine were also found normal, but during the period the patient was on propranolol therapy, all responses were decreased, within the normal range. These results do not positively support the idea that glucose receptor is linked to β-receptor. They do not either agree with the contention that secretions of insulin, glucagon and growth hormone induced by arginine are mediated through β-receptors.

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Two hr after birth, newborn rats were given a subcutaneous injection of 0.01mg estradiol benzoate dissolved in 0.05ml sesame oil. Other siblings were given sesame oil alone. Autopsy was performed on days 1, 2 and 3 after birth. Gravimetric and histologic examinations of the adrenals from these animals and from normal littermate controls were made together with the determination of plasma corticosterone concentrations. In all the three groups of rats, estrogen-treated, oil-treated and nontreated, the weight of the adrenal glands declined with a concomitant decrease in the plasma corticosterone concentrations. The results indicate that estradiol benzoate, when given after birth, does not prevent the neonatal adrenal from shrinking.

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Eight euthyroid subjects were administered 500μg of thyrotropin-releasing hormone intravenously before and after the administration of 10mg potassium iodide daily for 7 days. Basal serum concentrations of TSH and the response of TSH to TRH were significantly increased following iodide treatment, while serum levels of T₄ and T₃ did not differ significantly. It is suggested that the administration of 10mg/day of potassium iodide can produce similar changes in serum TSH to those in previous reports using large doses of iodide

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The following five tyrosine-containing analogs of somatostatin (GIF) were synthesized by the solid-phase method: Tyr-GIF;[Tyr⁶]-GIF;[Tyr⁷]-GIF;[Tyr⁸]-GIF;[Tyr¹¹]-GIF.These analogs except [Tyr⁸]-GIF were demonstrated to possess almost the same potency to inhibit thyrotropin release stimulated by thyrotropin-releasing hormone as that of synthesized GIF in vivo.[Tyr⁸]-GIF had potencies less than 0.5% of GIF. They also had the activity to inhibit Nembutal-induced growth hormone rise. The structure-activity relationship and availability of these analogs for radioimmunoassay were discussed.

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The effect of hypophysectomy on the hypothalamic somatostatin content was examined in rats. Somatostatin content in the acid extract of the pituitary stalk and the median eminence tissue (SME) was measured by specific radioimmunoassay.
In young male rats, the mean somatostatin content in SME was 63.9±5.0ng. Two weeks after hypophysectomy, it was reduced significantly to 34.4±3.3ng.
The result may indicate that the elimination of feedback actions of GH and/or TSH on the hypothalamus led to the decreased synthesis and/or the release of somatostatin. However, the possibility that structural changes in the pituitary stalk and the median eminence tissue ensued after hypophysectomy resulted in the depletion of somatostatin cannot be ruled out.

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