Search

The frequency of reports with ectopic ACTH syndrome is increasing year by year. But the intermittent function by hormone producing tumor has been reported rarely. We report a patient with ectopic ACTH syndrome caused by a carcinoid tumor of the thymus in whom remarkable fluctuating hormonal production was closely associated with the fluctuation of clinical features such as pigmentation, acne, edema, polyuria, and hypokalemia.

下垂体腺腫より過剰に分泌されるTSHにより, 2次的に甲状腺機能亢進症を呈したと考えられる1例を報告する.症例は48才,男性で,甲状腺腫を主訴として来院し, T34.2ng/ml, T423.3μg/dlと血中甲状腺ホルモン高値に加えTSHが7.9μU/mlと上昇していた.またTSH-αは8.9ng/mlと高値であり, TSH-βは0.2ng/ml以下であつた.頭部X線写真およびCTスキャンにて下垂体腫瘍を認めた. TSH, TSH-αおよび甲状腺131I摂取率は, T3の投与で抑制されず, TSH, TSH-αはTRHテストでは無反応であつたが,デキサメサゾンにより抑制され,インスリン負荷により奇異な上昇を示した. T3, T4はメチマゾール投与では低下しなかつたが,無機ヨードの投与により低下し, TSHは上昇した.経蝶形骨洞的下垂体腫瘍摘除術を施行し酵素抗体法を用いて腫瘍組織中に,抗TSH抗体,および抗TSH-α抗体に陽性を示す細胞が認められた.腫瘍中TSH, TSH-α含量はそれぞれ0.44mU/mg, 0.24μg/mg湿重量であつた.また,血清および腫瘍のホモジネートをゲル〓過し,各分画のTSH, TSH-αを測定し,標準物質および原発性甲状腺機能低下症患者の血中のそれと,ほぼ同一部位に熔出されることを確認した.

The effects of repeated doses of oral cholecystographic agents on serum thyroxine (T4), 3,3′,5-triiodothyronine (T3), 3,3′,5′-triiodothyronine (rT3) and thyrotrophin (TSH) concentrations were studied in 37 euthyroid male subjects. Iobenzamic acid, tyropanoic acid, iopanoic acid, and ipodate sodium, in a dosage of 3 g for 3 days, respectively, induced a significant decrease in serum T3 and an increase in rT3 within 24 h after the initial dose, followed by an increase in TSH and a slight increase in T4. The extent of the changes in rT3 varied between the agents, ipodate causing the greatest change, but without any relation to the changes in T3 or T4. Responses of serum T4, T3, rT3 and TSH concentrations to exogenous thyrotrophin-releasing hormone (TRH) and bovine TSH were also studied before and after 3-day doses of iopanoic acid. In 11 subjects given iopanoic acid, the response of TSH to TRH (500 μg, iv) was increased but the T3 response was unchanged. A dose of TSH (10 U.S.P. units, im) caused a significant increase in serum T3 and a decrease in TSH concentrations in 5 subjects both before and after cholecystography. It is thus suggested that in euthyroid subjects given multiple doses of oral cholecystographic agents, (1) the primary and consistent events are the reciprocal changes of serum T3 and rT3. although the extent of the changes is not coordinately reciprocal; (2) the responsiveness of the pituitary thyrotrophs and thyroid to TRH is preserved; and (3) the high basal and TRH-induced TSH in the serum may be ascribed to the decrease in the serum T3 concentration.

The response to exogenous parathyroid hormone (PTH) with urinary excretion of phosphate and cyclic adenosine monophosphate (cAMP) was tested by the use of synthetic human parathyroid hormone (1-34) [hPTH-(1-34)] on 59 patients with hypocalcemia and normal or high serum inorganic phosphorus and normal renal function without a history of parathyroidectomy for differentiation between idiopathic hypoparathyroidism (IHP), pseudohypoparathyroidism (PHP) and related diseases along with 18 normal subjects. A positive phosphaturic response to exogenous PTH was defined as the increment of 2 hours phosphate excretion (delta P) of more than 35 mg. A positive urinary cAMP response to exogenous PTH was defined as the increment by more than 1 mumole per one hour (delta cAMP) and the increase of 1 hour excretion by more than 10 times. Increments of 2 hours urinary phosphate excretion in response to hPTH-(1-34) 100 units were 60.5 +/- 7.7 mg (mean +/- SEM) in 27 patients with IHP, 23.5 +/- 5.9 mg in 21 patients with PHP type I and 24.9 +/- 4.0 mg in 17 normal subjects. Increments of 1 hour urinary cAMP excretion in response to hPTH-(1-34) 100 units were 12.0 +/- 1.5 mumole in 27 patients with IHP, 0.33 +/- 0.10 mumole in patients with PHP type I and 23.6 +/- 5.8 mumole in 15 normal subjects. Ratios of 1 hour urinary cAMP excretion were 97 +/- 10 in 27 patients with IHP, 3.6 +/- 0.5 in 21 patients with PHP type I and 54 +/- 14 in 15 normal subjects. Positive phosphaturic and negative urinary cAMP response was encountered in 3 out of 21 patients with PHP type I in response to hPTH-(1-34). This exaggerated phosphaturic response should be considered as due to the influence of treatment with Ca or vitamin D derivatives.

We have previously shown that some oral cholecystographic agents induce marked increase in basal and TRH-stimulated TSH concentrations in normal subjects. To define the relationship between circulating iodothyronines and pituitary secretion after oral cholecystography, temporal changes in the responses of serum TSH and PRL to a fixed dose of TRH (500 micrograms iv) and in serum T4, T3, and rT3 concentrations were assessed before, immediately after, and then at weekly intervals after the three daily doses of iopanoic acid (Ip). Both basal and TRH-stimulated TSH concentrations were significantly increased at the end of the period of Ip administration when the serum T3 concentration was decreased, were still above the pretreatment level 1 week after the course of Ip when the serum T3 had returned to pre-Ip levels, and returned toward normal 2 weeks after the course of Ip. The changes in serum T3 concentration were accompanied by reciprocal changes in rT3 concentration. PRL secretion was not significantly changed. To evaluate further the relationship between the enhanced TSH secretion and the changes in serum iodothyronine concentrations, subjects were given oral doses of T3 (5 micrograms every 4 h) or T4 (50 micrograms every 8 h) during the administration of Ip. In the subjects given Ip plus T3, serum T3 concentrations were maintained at pre-Ip levels, and both basal and TRH-stimulated TSH concentrations were not different from the control. Administration of T4 did not completely prevent the Ip-induced increment of TSH secretion. It is suggested that in subjects given Ip, 1) the serum T3 level is, at least partly, a determining factor for TSH secretion; and 2) the set-point of TSH secretion is appropriately tuned to either reduction or elevation of serum T3 concentration by a mechanism that is different from that in fasting subjects.

A kinetic analysis of iodine metabolism was performed on 7 normal subjects on an iodine-restricted diet, 7 normal subjects and 7 subjects with simple goiter on the usual Japanese diet. 1) The mean intrathyroidal iodine content was 12.2, 27.6 and 43.3 mg/gland, respectively. 2) The escape of nonhormonal iodine from the thyroid gland was confirmed in all cases despite the restriction of dietary iodine. 3) After the occurrence of leveling off of the daily urinary excretion of 131I, the mean daily excretion rate of urinary 131I (E*) was 5 times greater than the mean daily degradation rate of labeled hormonal iodine in the extrathyroidal organic iodine pool (D*) and was 3 times greater than the mean daily secretion rate of the labeled hormonal iodine from the gland (H*). 4) The ratio of the mean daily excretion rate of urinary 131I (E*) to the mean daily secretion rate of PB131I from the gland (H*) was used as one of the indices for the release of nonhormonal iodine. The relationship in 19 subjects be...

The response of thyroid weight and iodine metabolism to excess ingestion of iodide was studied in the chick. Treatment of chicks with 1mg of iodide for 4 weeks induced a marked increase in thyroid weight. The radiochromatography of the 131I labelled thyroid hydrolysate showed that a single injection of carrier iodide resulted in a significant but transient reduction of a relative proportion of organic 131I as well as thyronine 131I and an elevation of the MIT/DIT ratio. After chronic treatment of chicks with excess iodide, the thyronine 131I proportion was still decreased notwithstanding the fact that the organic 131I proportion showed a return to normal and MIT/DIT was rather low. The increased thyroid weight and decreased thyronine proportion returned to normal 9 weeks after termination of the iodide feeding. In the goitrous chicks, the relative proportion of intrathyroidal 127I compounds were virtually identical with that of 131I, although the absolute amount of thyronine 127I was increased depending on the increase in total 127I content. There was no significant difference in both turnover rate of radiothyroxine and plasma thyronine 127I concentration between the goitrous and control chicks. It is suggested that these alterations of iodine metabolism seem to be closely related to the mechanism of goitrogenesis by excess iodide in chicks and may represent an inhibitory effect of iodide on intrathyroidal hormogenesis.

A survey of goitre was made in the goitrous regions on the coast of Hokkaido, the northern island of Japan. Prevalence of goitre was confirmed in Hidaka coast and Rishiri Island. All goitrous patients were clinically euthyroid. The usual diet of the inhabitants of these districts consisted of a large quantity of iodine-rich seaweeds. Urinary excretion of iodine in five patients exceeded 20 mg per day. Studies of 131I and 127I metabolism were performed both during ingestion and after restriction of seaweed. When the patients were taking their usual diet, the mean thyroidal 131I uptake in 57 patients was 9.6% at 3 hours and 11.7% at 24 hours. In five of seven patients plasma inorganic iodine and thyroidal iodine space were markedly increased. Significant discharge of thyroidal 131I followed administration of thiocyanate. After withdrawal of seaweed from their usual diet, the plasma inorganic iodine was below 2 μg/100 ml but the thyroidal stable iodine uptake was higher than normal, depending on increase in thyroidal 131I clearance rate. No discharge was shown by thiocyanate block. Plasma PBI and thyronine-iodine level and serum T3 resin uptake were within the normal range. Radiochromatography of the thyroid tissue of the goitrous patients showed an increase in MIT/DIT ratio and a decrease in T3 + T4 proportion. No evidence for peripheral defect in DIT-131I deiodination was obtained. In a few patients restriction of seaweed induced a marked decrease in the size of goitre. The major cause of the endemic coast goitre seems to be excessive and longstanding intake of iodine from seaweed, and the similarities of iodine metabolism between the endemic coast goitre and iodide goitre arc discussed.

Perchlorate tests were performed after oral administration of radioiodine without carrier iodide (conventional perchlorate test) or with 500 μg of 127I (iodide-perchlorate test). In neither test was there a significant discharge of 131I in control subjects. In subjects treated with l-methyl-2-mercaptoimidazole positive discharge was observed with the iodide-perchlorate test, but not with conventional perchlorate test. Of 8 patients with Hashimoto's thyroiditis, only 2 showed positive discharge tests by the conventional perchlorate test, whereas the iodide-perchlorate test was positive in all these patients.

Our previous study of the iodide-perchlorate test in patients with Hashimoto's thyroiditis led to us to assess the significance of the test in patients with Graves' disease. Perchlorate tests were performed by a conventional method (ClO4 test) and a modified technique in which a dose of 250 or 500 μg 127I was added to the tracer 131I (I-ClO4 test). In the I-ClO4 test (500 μg 127I), a significant discharge was observed in the thyrotoxic patients, as well as in the patients rendered euthyroid by 131I treatment. With the smaller dose of 127I (250 μg), only 131I-treated patients showed significant iodide-perchlorate discharge. The magnitude of dischargeability (discharge percent) in the 131I-treated patients was greater than in thyrotoxic patients. ClO4 tests were negative in both the thyrotoxic and 131I-treated euthyroid patients. Chronic treatment with iodide induced hypothyroidism in 5 of 7 euthyroid patients who had been treated with 131I. The ClO4 test was negative in all patients except one, whereas the...

Chicks or rats were prelabeled by injection with Na131I. Slices from the excised thyroid glands were incubated at 4 C and autoproteolytic activity in each “extract” was determined by further incubation at 37 C after the addition of acetate buffer (pH 3.6) and separation of the radiometabolites by paper chromatography. Proteolytic activity in the thyroid extracts from chicks which had been previously maintained on 1 mg of iodide/day for 4 weeks and which had developed goiters was decreased to one third of that in the thyroid glands from normal control chicks. A slight decrease in autoproteolytic activity was also observed in the thyroids from chicks after a single injection of 1 mg of iodide. In rats maintained on 0.5 mg of iodide/day for 3 weeks or given a single injection of 0.5 mg of iodide, the decrease in thyroid proteolytic activity was small compared with that in control chicks. In thyroid glands of chicks or rats in which proteolytic activity was decreased following the treatment with iodide, iodot...