Endocrinologia Japonica
Online ISSN : 2185-6370
Print ISSN : 0013-7219
ISSN-L : 0013-7219
Volume 31, Issue 2
Displaying 1-15 of 15 articles from this issue
  • HARUO TAMAKI, NOBUYUKI AMINO, YOSHINORI IWATANI, MINORU KAWASHIMA, HIR ...
    1984 Volume 31 Issue 2 Pages 99-108
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The relationship of structural polarity to functional activities was examined in cultured human thyroid follicles, which were isolated from the thyroid gland of patients with Graves' disease by collagenase treatment. Structural polarity was examined morphologically by electron microscopy, while the functional response to bovine TSH was examined by measuring intracellular cAMP accumulation and T3 release. In freshly isolated thyroid follicles, structural polarity was normal and TSH induced significant cAMP accumulation but no significant release of T3. After culture for 5 days the structural polarity of thyroid follicles became inverted in the absence of thyroid stimulators, but normal polarity was retained in the presence of TSH or dibutyryl cAMP ((Bu) 2 cAMP). The response to TSH of cAMP accumulation increased markedly after culture in either the presence or absence of TSH, suggesting that cAMP accumulation in response to TSH is not related to structural polarity. In contrast, thyroid follicles cultured without thyroid stimulators showed no significant T3 release in response to TSH, whereas those cultured with TSH or (Bu) 2 cAMP showed significant T3 release in response to TSH. These data indicate that in cultured human thyroid follicles, the responses to TSH of cAMP accumlation and T3 release are not always correlated. Among many other explanations, the results were at least compatible with the idea that normal structural polarity is necessary for thyroid hormone release in reponse to TSH.
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  • HAJIME NAWATA, KAZUMI HIGUCHI, MASAYOSHI HIGASHIZIMA, KEN-ICHI KATO, H ...
    1984 Volume 31 Issue 2 Pages 109-116
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Glucocorticoid receptors (GR) in cultured fibroblasts obtained by forearm skin biopsy were characterized and GR in patients with hyper- and hypocortisolism were compared. Scatchard analysis of specific whole cell [3H]-dexamethasone binding showed a single class of high affinity receptors with a mean (±SD) binding capacity (R0) of 126, 800±21, 600 sites/cell and mean (±SD) apparent dissociation constant (Kd) of 2.9±0.4 nM in 6 normal subjects. Competition study of various steroids revealed that glucocorticoids were the most potent competitors. The order of the strength of competition was dexamethasone > betamethasone > prednisolone > hydrocortisone. Sucrose density gradient analysis revealed a specific 8.6 S binding peak in cytosol and 3.6 S in nuclear extracts. Dexamethasone showed the dose-dependent suppressive effect on thymidine incorporation. An inverse linear correlation between CI50 and % inhibition of thymidine incorporation by glucocorticoids was observed. There were no significant differences in parameters of whole cell GR among healthy controls, Cushing's disease (n=4, R0=131, 225±29, 950/cell, Kd=3.1±0.6 nM) and Addison's disease (n=2, R0=131, 600±25, 600/cell, Kd=3.2±0.2 nM). In one additional patient of hypercortisolism without clinical symptoms of Cushing's disease, R0 (144, 000±12, 960) was the same as control, but Kd (5.0±1.2 nM) was higher than the control.
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  • SEIICHI SUMI, KIKUO ICHIHARA, NORIO KONO, KYOHEI NONAKA, SEIICHIRO TAR ...
    1984 Volume 31 Issue 2 Pages 117-125
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    In order to study the effect of insulin and epidermal growth factor (EGF) on glycolysis in quiescent 3T3 fibroblasts and their mechanisms of action, l actic acid produced by cells and activities of key glycolytic enzymes in cell extracts were determined. Insulin increased lactic acid production; the maximal stimulation occurred at the concentrations above 250 ng/ml and the halfmaximal dose was 50ng/ml. This effect of insulin appeared as early as one hour, and lactic acid production in the presence of insulin linearly increased up to 4 h. The 24-h pretreatment with insulin exhibited no significant effect on the production by cells afterward incubated either with or without insulin. Lactic acid production decreased as the concentration of phloridzin increased. However, insulin stimulation of the production still remained in the presence of phloridzin. Parahydroxymercuribenzoate reduced production only by the equivalent of the increase due to insulin. EGF also increased lactic acid production ; this effect occurred at 1 ng/ml and was maximal at 100 ng/ml. The activities of hexokinase, phosphofructokinase and pyruvate kinase in quiescent cells were not increased by insulin, and the affinities for substrates of these enzymes remained unaltered. These findings suggest that glucose uptake is a rate-limiting step in glycolysis in quiescent 3T3 fibroblasts and that the stimulatory effect of insulin on glycolysis is mediated by enhanced glucose entry.
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  • HIROSHI MATSUSHITA, MITSURU HARA, YOSHIMASA SHISHIBA, HIDEKI NAKAZAWA
    1984 Volume 31 Issue 2 Pages 127-131
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The size of the parathyroid gland was evaluated at different functional levels of the gland (control: 216 glands in 54 autopsy cases, chronic renal failure: 74 glands in 21 autopsy cases, hypercalcemia: 16 glands in 15 patients with primary hyperparathyroidism). This study is based on the fact that chronic renal failure causes a hypersecretory state of parathyroid hormone (PTH), and that hypercalcemia suppresses PTH secretion. The size of the parathyroid gland was represented by the largest area cut through the hilum of the gland. Interstitial and fatty tissues were excluded from the measuring.
    The lower parathyroid glands are larger than the upper glands in the control. Both the upper and the lower glands enlarge with a predominance of the lower glands in size in chronic renal failure. These results suggest that the functional level of the lower glands is higher than that of the upper glands not only in the normal but in a hypersecretory state of PTH. Hypercalcemia has been shown to cause a decrease in size of the lower glands, while the upper glands scarcely decrease in size. This result indicates that the lower glands play a major role in reducing PTH secretion when PTH secretion is suppressed.
    It is concluded that the lower parathyroid glands play a more important role than the upper glands in the maintenance and regulation of PTH secretion.
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  • TOSHIAKI TANAKA, TADASHI AIBA, YOSHIMASA SHISHIBA
    1984 Volume 31 Issue 2 Pages 133-140
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The heterogeneity of hGH in the sera, culture media of tumor cells and tumor extract from acromegalic patients was studied employing gel chromatography, RIA and lymphoma cell bioassay.
    The chromatographic profile of the sera on Sephadex G-100 (superfine) column showed three peaks: the major peak eluted with 125I-hGH (little hGH), the less retarted small peak (big hGH) and the peak at void volum (big-big hGH). Bioassay to radioimmunoassay ratio of big-big, big and little hGH were 1.07-5.75, 0.25-0.70 and 0.70-1.56, respectively. These ratios were not significantly different among the acromegalic sera obtained before and after TRH test.
    The longer duration sera were kept for, the higher percent of big-big hGH and the lower percent of little hGH the sera contained by RIA. The percentage of big-big hGH was less in the culture media of tumor cells than that in acromegalic sera, and the least in tumor extract by RIA. Rechromatography of big-big hGH fraction of tumor extract showed the conversion of big-big hGH to big and little hGHs. These data suggest that big-big hGH was artificially made from little and big hGH during storage.
    Rechromatography of fractions between big-big hGH and big hGH produced another peak (medium-big hGH) with approximately 80 K-90 K daltons of molecular weight. This peak was converted to almost a little hGH peak after mercaptoethanol treatment and was supposed to be a tetramer of little hGH.
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  • KAZUTAKA HARAGUCHI, KIYOSHI HASHIZUME, KAZUO ICHIKAWA, MUTSUHIRO KOBAY ...
    1984 Volume 31 Issue 2 Pages 141-149
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The effect of thyroid hormone on the high affinity Ca2+-ATPase activity in rat liver plasma membrane was studied.
    The high affinity Ca2+-ATPase activity in plasma membrane was activated by 10-7-10-5 M of Ca2+ and was inhibited by 70μM trifluoperazine.
    Thyroidectomy of rats was associated with an increase in the activity of high affinity Ca2+-ATPase. The increased enzyme activity was normalized by T4 administration to the animals. On the other hand, Na+-K+-ATPase activity in the membrane was decreased by thyroidectomy and the decreased enzyme activity was normalized by T4 administration.
    The results suggest that thyroid hormone inhibits the Ca2+ extrusion system by inhibiting calmodulin-independent high affinity Ca2+-ATPase in liver plasma membrane.
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  • NOBUO KUGAI, YOSHINOBU KOIDE, SATOSHI KIMURA, KAMEJIRO YAMASHITA
    1984 Volume 31 Issue 2 Pages 151-158
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    To study the effects of various vitamin D preparations on PTH secretion, serum calcium and urinary excretion of cAMP were monitored in conscious perfused rats, and the influences of a bolus iv injection of the preparations on these parameters were examined. Three hours after the administration of 0.25 μg/kg (0.6 nmol/kg) of 1α, 24 (R)-dihydroxycholecalciferol [1α, 24 (OH) 2D3], the urinary excretion of cAMP decreased to a level compatible with that of parathyroidectomized (PTX) rats (50% of initial value; p<0.05) with no change in the concentration of serum calcium (total and ionized). In PTX rats supplemented with bovine PTH (1 U/h), the vitamin D preparation showed no significant effects either on the urinary excretion of cAMP or on serum calcium. These effects were rather specific for active vitamin D preparations, i. e. 1α, 25 (OH) 2D3 (0.25μg/kg) and 1αOHD3 (1.25-6.25μg/kg). However, 24, 25 (OH) 2D3 (up to 25μg/kg) had no significant effect on these parameters. These results suggest that, in rats, active vitamin D preparations specifically inhibit PTH secretion without causing a significant increase in the serum calcium concentration, reflecting a direct feedback mechanism between active vitamin D metabolite and the parathyroid glands.
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  • Comparison with 13 Previously Experienced Cases with Hypertension
    TAKATOSHI NISHIMIYA, KENJIRO KIKUCHI, HIROSHI OIMATSU, SHIGEKI OTA, YA ...
    1984 Volume 31 Issue 2 Pages 159-164
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    A 47-year-old woman with normotensive primary aldosteronism is reported. In this case, hypopotassemia was found, but the patient's blood pressure was within the normal range. Her condition was diagnosed as primary aldosteronism without hypertension, which is very rare, based on an increased level of plasma aldosterone concentration, low plasma renin activity, and a typical finding of aldosterone-producing adenoma by adrenal scintigraphy. In the present case, similar values for urinary volume, renal function, plasma aldosterone concentration, plasma renin activity, plasma volume, total exchangeable sodium, urinary kallikrein excretion and a similar weight of the resected adenoma, but a shorter duration between the onset of symptom and hospital admission were observed as compared with those in 13 previously experienced cases of primary aldosteronism with hypertension. Thus, a shorter duration of primary aldosteronism appears to be an important factor in explaining the mechanism of normotension. However, we were unable to reach a definite conclusion and this is only a hypothesis. Further investigation will be required to clarify the mechanism of normotension in primary aldosteronism.
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  • Possible Dependence on Protein Synthesis
    KUNIO SHIOTA, KEIJI YOSHIDA, TSUNEO MASAKI, MASAHIRO KAWASE, RYO NAKAY ...
    1984 Volume 31 Issue 2 Pages 165-175
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Mechanisms related to the biphasic release of TSH were studied using primary cultured cells of the rat anterior pituitary gland on micro-carrier beads in a superfusion system. Release of TSH in response to continuous exposure to TRH exhibited a biphasic pattern; the first phase was characterized by a rapid, transient and high-rate release (phase I) and the second phase by a chronic and low-rate release (phase II). The shift of the release from phase I to phase II occurred by treatment with TRH at concentrations from submaximal to maximal. When the Ca2+ concentration in the medium was decreased, the phase I release was partially inhibited, while the phase II release was completely inhibited, suggesting a difference between the mechanisms in phase I and phase II release. The phase I release was not suppressed by cycloheximide. This protein synthesis-independent release of phase I seemed to be linked to the intracellular releasable pool of TSH. The phase II release was suppressed by the presence of a protein synthesis inhibitor. After the phase II release was suppressed by cycloheximide, the magnitude of phase I release in response to re-exposure to TRH markedly decreased. The decreased phase I release in response to TRH was observed with the cells which were previously stimulated by high K+instead of TRH, suggesting that the decrease in the response of phase I reflects the depletion of a releasable pool of TSH rather than homologous desensitization of thyrotrophs with TRH. These results suggest that the phase I release of TSH depends on a portion of the previously prepared-releasable pool while phase II release depends on previously prepared plus newly prepared pools of TSH. Replenishment of the releasable TSH pool was considered to involve protein synthesis.
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  • SACHIKO MUKAI, MITSUHIRO OKAMOTO, TOSHIO YAMANO, KAZUNORI ISHIMURA, HI ...
    1984 Volume 31 Issue 2 Pages 177-184
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Rat adrenocortical cell suspensions (106 cells) were incubated with ACTH (40nM) in 2ml of Krebs-Ringer bicarbonate buffer for 90 min. About 42 nmol of corticosterone and 14 nmol of 18-hydroxydeoxycorticosterone were generated and released into the medium. Aminoglutethimide at 50μM inhibited the steroidogenesis to 16%. Mitochondrial pellets were prepared from the cells incubated in the absence, or in the presence, of ACTH and aminoglutethimide, and cholesterol content was determined. The mitochondria of the cells incubated without the drugs contained 25.2 fig cholesterol/mg protein. Cholesterol content increased by 10% in the mitochondria of the ACTHstimulated cells. The mitochondria of the cells incubated in the presence of both ACTH and aminoglutethimide contained 143% of cholesterol compared to those of the nontreated cells. When rats were subjected to ether stress after aminoglutethimide pretreatment, cholesterol content of the mitochondrial fraction increased to about 200 % compared to that of the control rats. These results suggest that a cholesterol pool exists in the adrenocortical mitochondria and that the amount increases during the steroidogenic stimulation of the cells. The mitochondria were fixed with filipin-containing fixative and examined by freeze-fracture electron microscopy. Accumulations of filipin-cholesterol complexes were observed in the inner membrane of the mitochondria as protuberances or pits 25 nm in diameter.
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  • MASAKAZU TAKAHASHI, KATSUMI WAKABAYASHI, SUMI NAGASE
    1984 Volume 31 Issue 2 Pages 185-193
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The hormone levels in the anterior pituitary gland and serum in Nagase analbuminemia rats (NAR), a mutant strain established from Sprague-Dawley rats with hyperlipidemia, were examined. For the anterior pituitary gland, the prolactin, TSH, GH, LH and FSH contents in male NAR were significantly lower than those of normal rats. In female NAR, prolactin, TSH and LH levels were also lower than those in normal rats, whereas FSH and GH were normal. For the serum, the concentrations of TSH, total T3, total and free T4, estradio1-17β and testosterone were examined. The serum testosterone concentration in NAR was lower than that of normal rats. Histochemical examination of the hydroxysteroid dehydrogenase (HSD) activity of testes was made in relation to the serum testosterone level. NAR testes, which are rather small compared with those of normal rats, have lower HSD activity. A higher level of serum TSH was seen in NAR. Total and free T4 concentrations were low in the male NAR only. Estradiol-17β and T3 concentrations in NAR were unchanged. Changes in serum LH and FSH levels during the estrous cycle in NAR were also studied. Their patterns of change are normal.
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  • Simultaneous Assay of PRL as a Pituitary Marker
    KOSHI TANAKA, NAOKATA SHIMIZU, MEGUMI NAGATA, TATSUO SEKI, JUN NAGAI
    1984 Volume 31 Issue 2 Pages 195-200
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    To identify an obscure site of excessive ACTH production, selective venous sampling was performed by Seldinger's method in a 32-year-old man. Differential diagnosis between an ectopic ACTH producing tumor and Nelson's syndrome was quite inconclusive in this patient in spite of extensive clinical and laboratory evaluations, including pituitary surgery. In this study, PRL was measured in every sample as a reliable marker for pituitary drainage. Significantly higher rations (2.6 to 5.3) of catheter to peripheral (C/P) concentration of PRL at sites closer to the pituitary indicated successful samplings of pituitary drainage. C/P ratios of ACTH correlated very closely (correlation coefficient=0.906, p<0.01) with those of PRL at every sampling site. Thus, it was concluded that the site of excessive ACTH production in this patient was in the pituitary gland. The methods applied in this study appear to be useful in differentiating ectopic from eutopic production of other pituitary hormones as well.
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  • KAZUO SHIZUME
    1984 Volume 31 Issue 2 Pages 201-206
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The results of 6 months to 8 years of treatment of pituitary dwarfism in 1, 959 patients in Japan were summarized. The data were based on the reports of the physicians treating the patients. Among the patients, 1, 720 cases suffered from idiopathic pituitary dwarfism, 227 cases from secondary pituitary dwarfism, and 12 cases from unknown causes. Their initial age ranged from 9 months to 36 years old and their initial bone age ranged from 3 months to 15 years old. In most cases, a definite effect was observed. The effect was most remarkable during the initial 6 months and then declined gradually up to the fourth year. Males responded better than females. In younger and more immature patients, the effect was more remarkable. There were almost no side effects other than a few cases of impairment of capital femoral epiphysis.
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  • YUICHI WADA, AKIRA YAJIMA, MASAKUNI SUZUKI, GILBERT GREENWALD
    1984 Volume 31 Issue 2 Pages 207-215
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    In order to assess the direct luteotropic effects of steroids, dispersed luteal cells from rats on day 8 or 16 of pregnancy were incubated for 2h with various concentrations of estradiol (1-1000ng/ml), testosterone (1-100ng/ml) or progesterone (1-100ng/ml).
    Estradiol, at any concentration, did not cause significant changes in the in vitro accumulation of progesterone, 20a-dihydroprogesterone (20α-OHP) or testosterone by dispersed luteal cells on both days 8 and 16. Addition of testosterone (1-100 ng/ml) increased the accumulation of estradiol on day 8 with estrone synthesized at half to one third the rate of estradiol. On day 16, accumulation of estradiol by dispersed luteal cells was more sensitive to 1ng/ml testosterone than on day 8 with a concomitant drop in estrone synthesis.
    Although luteal secretion of estradiol was readily stimulated by testosterone, there were no corresponding changes in the production of progesterone or 20α-OHP.
    Although the addition of a small amount of progesterone did not cause the anticipated increase in accumulation of 20α-OHP, 100 ng/ml progesterone elicited a slight but significant increase in accumulation of 20α-OHP on day 8.
    Thus, none of 3 steroids added was found to exert any direct in vitro luteotropic action in the pregnant rat, in acute experiments.
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  • 1984 Volume 31 Issue 2 Pages e1
    Published: 1984
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
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