The livers removed from thyroidectomized and L-T₄ supplemented rats were rapidly frozen by Freon-12 chilled with liquid nitrogen, and concentrations of metabolites which affect glycogen synthetase and phosphorylase were determined. Serum liver glucose levels were not changed in any state of thyroid functioning. But G6P and ATP were increased by thyroidectomy and decreased by L-T₄ supplement, while cAMP was increased by the hormone supplement.
The “enzyme activity” ratio of glycogen synthetase a to phosphorylase a was increased by thyroidectomy and decreased by L-T₄ supplement. The most intimate correlation was observed between the “enzyme activity” ratio and the ratio of the “energy charge” ratio to cAMP among other indices calculated from changes in the metabolite concentrations in the various thyroid functioning.
The change in the substrate levels brought about by thyroidectomy and L-T₄ supplement appeared to modulate both the enzyme activities which in turn regulate the glycogen metabolism.

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The association constants and the binding capacities of association of small molecules with macromolecules have been determined by the tangent analysis, the graphical analysis, and the computer data analysis by trial and convergence of the Scatchard plot. The analytical method for the calculation of the binding parameters based on the Scatchard plot was derived and the optimum values of the binding parameters were obtained by the least-squares calculation based on the analytical method. The errors by the analytical method were smaller than those by the graphical method in the equilibrium system between ³H-estradiol and some cytosols of uterus.

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A new method for the estimation of the maximal T₄-binding capacity of TBG (max. TBG) in serum (dextran-coated charcoal-triosorb method) was devised. Thyroxine (T₄) concentration in test sera were determined by the Tetrasorb method and then T₃ resin sponge uptake (T₃ RSU) was determined after extraction of 70% of the endogenous T₄ with dextran-coated charcoal. The binding capacity of unsaturated TBG in treated sera was estimated from the reciprocal of T₃ RSU. Max. TBG was calculated from the arithmetic sum of the unsaturated binding capacity of TBG and the serum T₄ concentration multiplied by 0.3. The normal range for max. TBG was 20.1±2.6 (mean±SD)μg T₄/100ml (14-24) and it was 19.2±3.5μg T₄/100ml in hyperthyroidism which was lower compared with hypothyroidism (21.1±2.6μg T₄/100ml). Max. TBG in 8 hyperthyroid patients did not change significantly after treatment in half of the case, although in the other half it was slightly increased. Increased values of max. TBG were observed in pregnancy (32.9±4.4) and in a hyperthyroid state associated with pregnancy (31.4±4.7). Decreases were observed in TBG deficiency (<5.6μg T₄/100ml). These procedures can be applied for the determination of both the unsaturated binding capacity of TBG and that of max. TBG.

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C-peptide immunoreactivity (CPR) was demonstrated not only in plasma, but in urine, ascites, cerebrospinal fluid and pleural effusion.
The concentration of CPR in urine was very high compared with that in the other body fluids and was easy to assay. CPR in urine after glucose administration or tolbutamide injection increased parallel to the change of CPR in plasma and also to that of IRI in normals or diabetics without renal disturbances.
The results suggest that the determination of CPR in urine before and after stimulation of insulin secretion could serve as a simple indicator of insulin secretory function of pancreas.

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Partial purification of prolactin-release stimulating factor (PRF) was performed by Sephadex G-25 gel filtration of bovine hypothalamic extracts. PRF activity was evaluated on the basis of the measurement of immunoreactive prolactin released from the isolated rat hemipituitary in vitro. PRF activity was found in the fractions with Kav=0-0.49 and prolactin-release inhibiting activity was also detected in the fractions with =0.69-0.89. The dose-response relationship was established between the partially purified PRF and its activity. The elution position of the partially purified PRF preceded that of TRH on Sephadex G-25. TRH at the dose of 100nM stimulated the release of TSH in vitro, but not the release of prolactin.
These results may indicate that there exists PRF with a relatively high mo lecular weight in the bovine hypothalamus.

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The role of the pineal gland in inducing and maintaining the persistent estrus of rats exposed to continuous illumination was examined. Under the cyclic illumination, the pinealectomy or sham-operation revealed no effect on the estrous cycle, although weights of the ovaries, adrenals and hypophysis were slightly but definitely greater in the pinealectomized animals. In rats exposed to the continuous illumination immediately after pinealectomy or sham-operation, both groups exhibited the persistent estrous states soon after the change of lighting condition. In these rats, neither the degree of persistent estrus nor the organ weights at autopsy showed any significant difference between the groups. Moreover, the pinealectomy could not alter the incidence of estrous phases in persistent estrous rats which had been established already by the continuous illumination.

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Preoperative physical and radiological findings, if specific to a certain extent, are important for detecting patients with sporadic form of medullary thyroid carcinoma and especially for the first patient in the family having a hereditary form of medullary thyroid carcinoma and pheochromocytoma syndrome. To delineate clinical features of medullary thyroid carcinoma, a total of 9 patients with this tumor were reviewed retrospectively. In most patients, the thyroid lesions were located in the upper two thirds of the lobe, which was determined by careful palpation or ¹³¹I scintiscanning of the thyroid. The primary lesion in the thyroid could be felt more or less as a round, sharply demarcated nodule with fairly good mobility. These findings suggested rather a benign thyroid nodule when there was no lymph node involvement. However, it could be considered a sign suggesting medullary thyroid carcinoma when accompanied by marked lymph node metastasis. In our recent 2 cases, the diagnosis of medullary thyroid carcinoma was strongly suspected on these clinical bases, one of the cases being presented in detail. In 4 patients, lymph node metastasis in the central neck extended to either submandibular or upper mediastinal regions or both. In about one third of the patients, calcified deposits were shown in the cervical roentgenograms. With the use of soft tissue roentgenography, grossly punctate calcific deposits associated with psammoma-like shadows were recognized and the pattern was a criterion for definitive diagnosis of medullary thyroid carcinoma.

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Female rats were irradiated with 190R of X-rays at 10 days of age and sacrificed 4, 7 or 12 months later. Their ovaries were histologically examined and serum levels and pituitary contents of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were determined by radioimmunoassay. Both serum levels and pituitary contents of LH and FSH rose significantly 4 and 7 months after irradiation, although the ovaries were markedly reduced in weight. On the contrary, 12 months after irradiation, the ovaries increased in weight and consisted mostly of polyhedral, hyperplastic interstitial cell masses, and both LH and FSH in the serum and pituitary were reduced to normal levels.
These characteristic changes in the ovarian weight and histological appearance could not be observed in the similarly irradiated animals which were received daily injections of estrone for the first 30 days of postnatal life, i. e., daily injections of 50μg for the first 10 days, 100μg for the middle 10 days and 200μg for the last 10 days. Serum LH levels of the estrogenized irradiated rats at 7 or 12 months of age did not elevate although those of FSH were significantly higher than the non-irradiated intact levels.
From these results, a rise in the blood levels of LH and FSH may be attributed to the increase in weight and the histological changes in the ovaries of the irradiated female rats, and the elevation of only FSH level may not result in the abnormal growth of the irradiated ovaries.

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Lordosis behavior was very rare in castrated male rats which had been pretreated with 50 μg estradiol benzoate (EB) for successive 2 days and 1 mg progesterone (P) 6-8 hr prior to testing on the third day. Only one out of 8 rats displayed lordosis in response to mounts by the sexually matured males. However, the occurrence of lordosis behavior was markedly increased in similarly treated castrated males in which the dorsal afferents to the preoptic area (POA) and hypothalamus were removed by the surgical cut. Twelve out of 19 rats of the group showed lordosis response. The incidence was less frequent in rats receiving sham deafferentation. These results suggest that the dorsal inputs to the POA and hypothalamus may exert a tonic inhibitory influence on the lordosis mediating system in the male rat.

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A sensitive and specific double antibody radioimmunoassay has been developed capable of measuring LH-RH in extracted human plasma. Thyrotropin releasing hormone, lysine vasopressin and most of LH-RH analogues did not appear to affect the assay. Hypothalamic extract and some of the LH-RH analogues produced displacement curves which were parallel to that obtained with the synthetic LH-RH. Sensitivity of the radioimmunoassay was about 3 pg per assay tube. The coefficient of variation of intraassay was 6.4%, while that of interassay was 9.6%. Exogenous LH-RH could be quantitatively extracted by acidic ethanol when varying amounts of synthetic LH-RH were added to plasma. Immunoreactivity of LH-RH was preserved in plasma until 2 hr in the cold and gradually reduced thereafter. The plasma levels of LH-RH were 20 pg/ml or less in normal adults and not detectable in children. The aged males over 60 yr and postmenopausal women showed a tendency to have higher levels of plasma LH-RH. Plasma LH-RH level was significantly higher in midcycle than in follicular and luteal stages. The disappearance rate of LH-RH from the circulation after intravenous injection could be represented as half-times of 4-6 min. Between 0.2-0.4% of the injected dose was excreted into urine within 1 hr. These results indicate that the determination of LH-RH might be a useful tool for elucidating hypothalamic-pituitary-gonad interactions.

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Serum T₃ level in various thyroid diseases was determined in unextracted serum with the Dainabot kit for T₃ RIA. The serum T₃ level in 33 normal subjects was 0.8-1.6ng/ml. It was 5.7±3.5ng/ml (mean± S.D.) in 36 hyperthyroid patients, and undetectable to 0.8 ng/ml in 21 hypothyroid patients.
Generally the serum T₄ and serum T₃ decreased in parallel after radioiodine therapy for hyperthyroidism. However, in some cases the serum T₃ level remained high in spite of normalized serum T₄ after radioiodine therapy. This state indicated “T₃-toxicosis”, and hyperthyroidism was apt to recur. When thyroid function was observed for 2 years following radioiodine treatment, the ratio of serum T₃ (T₃ level before treatment/T₃ level after treatment) decreased more significantly as compared with the ratio of serum T₄ in euthyroid cases. Serum T₃ provides a more sensitive index of thyroid function than serum T₄ in euthyroid states after radioiodine or anti-thyroid drug therapy.
The present data indicate that the serum T₃ level and the T₄/T₃ ratio are valuable aids in the estimation of prognosis of hyperthyroid patients after various treatments.

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The corpus luteum in mature Sprague Dawley rats was weighed at the various stages of pseudopregnancy and pregancy. The average size of these corpora lutea was 1.0±0.10mg, 1.61 ±0.69mg, 1.90±0.25mg, 3.69±0.36mg, and 4.37±0.50mg on day 2 of diestrus, on days 10-15 of pseudopregnancy, on days 9-10, 14, and 20 of pregnancy, respectively. The fact that the average size of the corpus luteum on days 10-15 of pseudopregnancy was larger than that on day 2 of diestrus is thought to drive from prolonged exposure of the corpus luteum to prolactin. The average size of the corpus luteum on days 9-10 of pregnancy had a tendency to be larger than that on days 10-15 of pseudopregnancy and this seems to demonstrate that the placenta secreted placental lactogen by this stage of pregnancy. The average size of the corpus luteum on day 14 of pregnancy was larger than that on days 9-10 of pregnancy. This phenomenon might be attributed to the presence of large amounts of placental lactogen secreted from the placenta between days 10 and 14 of pregnancy. Furthermore, it was noted that the size of the corpus luteum on day 20 of pregnancy was larger than that of day 14, which suggests that further secretion of placental lactogen continued after day 14 of pregnancy. As there was a remarkable decrease in the number of fetuses on day 20 of pregnancy when ovariectomy was performed on day 14 of pregnancy, the ovary was considered indispensable in maintaining pregnancy in the rat.

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An acromegalic patient with galactorrhea was treated with an ergot alkaloid, 2-Br-α-ergocryptine (CB-154). Serum prolactin decreased rapidly to normal level by CB-154 and the complete cessation of galactorrhea was noted. The inhibitory effect of CB-154 on growth hormone (GH) release was also noted, but slight. The mechanism of inhibitory action of CB-154 on both prolactin and GH secretion was discussed in connection with the experimental model of pituitary tumors, in which both hormones were produced by a single type of tumor cells. The discontinuation of CB-154 treatment was associated with the return of both prolactin and GH levels to the initial high values with resumption of galactorrhea.

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In a 41 year-old patient with Klinefelter's syndrome, a failure of TRH-induced TSH secretion was noticed. Low 131I-thyroid uptake, together with the elevation following exogenous TSH administration, indicates that the defective locus exists in the hypothalamus or pituitary resulting in an impaired secretion of TSH. Such a defect may underlie thyroid dysfunction often associated with Klinefelter's syndrome.

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The culture medium of mouse placental tissues was analyzed on acrylamide gel electrophoresis to localize lactogenic substances. Placental explants from 12-or 14-day-pregnant BALB/cHe mice were organ-cultured for 6 days in leucine-free Waymouth's medium supplemented with ³H-leucine (10μCi/ml) and insulin (0.12 I. U./ml). The medium was collected every other day and subjected to acrylamide gel electrophoresis. The electrophoretic pattern of radioactive leucine incorporated into proteins was examined on stained 7% gels. Five protein bands were associated with high radioactivity. The location of lactogenic activity on acrylamide gel was then investigated by the technique of organ culture of mouse mammary tissues. Placental explants from 12-or 14-day-pregnant BALB/cHe mice were organ-cultured in Waymouth's medium supplemented with insulin for 2 days. After electrophoresis, proteins were eluted by keeping the segment of acrylamide gel in phosphate buffer, dialyzed and dissolved in tissue culture medium 199 supplemented with insulin and cortisol. Mammary tissues from 8-day-pregnant KA2 mice were cultured for 3 days in the medium containing each eluate. Mammary glands always responded to eluted proteins from two positions of 7% gel, as judged in histological sections. The data suggest the presence of two lactogenic substances in the mouse placenta.

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