Several authors have reported that metoclopramide (MCP), a dopaminergic antagonist, stimulates aldosterone secretion and that dopamine (DA) inhibits the MCP-mediated aldosterone secretion in man. However, many controversial results have been reported relating to the direct effect of MCP and DA on the secretion of aldosterone by adrenocortical cells in in vitro experiments. The present studies were designed to determine whether or not MCP and DA exerts its effect directly on the cultured human adrenocortical adenoma cells and adjacent non-adenoma cells obtained from patients with primary aldosteronism. A bolous intravenous injection of 10 mg MCP significantly increased the plasma aldosterone concentration (PAC) from 255 ± 57 pg/ml (mean ± SD) to 386 ± 98 pg/ml after 15 min in patients with primary aldosteronism. But MCP (10^-10-10^-16M) failed to increase aldosterone secretion from both adenoma cells and non-adenoma cells in culture. DA (10^-9 and 10^-6M) did not suppress the basal secretion and the enhanced secretion of aldosterone by A II or ACTH in cells of either culture. The analysis by HPLC showed that 57% of dopamine hydrochloride added in the medium was preserved after 60 min incubation. These results suggest that MCP and DA do not act directly on the human adrenal glomerulosa cells in the regulation of aldosterone secretion.

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We have studied the internalization of insulin and the mechanism of insulin degradation in cultured Bri-7K human lymphocytes. The internalization of ¹²⁵I-insulin was observed by using an acid extraction technique by Heigler's method which removed surface-bound insulin, leaving only intracellular insulin associated with cells. Insulin binding to Bri-7K cells reached a peak at 15 min and showed a gradual fall thereafter at 37°C. Internalization of insulin rose with a peak in 30 min, and its rate was nearly 25% of the total specific cell-associated radioactivity. Insulin degrading activities in Bri-7K cells were examined as to precipitability with trichloroacetic acid (TCA method), Sephadex G-50 column chromatography (gel chromatography method) and the ability to bind to specific receptors on Bri-7K cells (rebinding method). Under conditions demonstrating that the insulin degradation didn't take place in the medium but was cell-mediated, the insulin degradation was not demonstrated by the TCA method. Chromatographic studies showed that the extractable radioactivity consisted almost entirely of intact insulin, whereas the supernatant and the nonextractable radioactivities consisted of large molecular weight material and intact insulin. Thus, the apparent degradation of insulin was not detectable by the TCA and gel chromatography methods, however, using the rebinding method, we could obtain results demonstrating that fair amounts of insulin in the supernatant were degraded. These results suggest that the products of insulin degradation are peptides with a molecular size similar to insulin itself but with little or no receptor binding activity.
In conclusion, insulin internalizes into Bri-7K cells at physiological temperature, and the mechanism of insulin degradation in Bri-7K cells seems to be a limiting proteolysis of insulin by specific enzyme (s).

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It is well recognized that in the fetal adrenal cortex, 3β-hydroxysteroid dehydrogenase (3β-HSD) activity is lower and in fetal tissues, steroid sulfokinase (SK) is higher than in the adult. In order to clarify a part of the developmental processes of the adrenal cortex or steroidgenesis in humans, a combined radioimmunoassay (RIA) method to estimate serum 17α-hydroxypregnenolone (17-OH-Δ⁵P), 17α-hydroxypregnenolone sulfate (17-OH-Δ⁵ P-S) and 17α-hydroxyprogesterone (17-OH-Δ⁴P) was devised.
The method consisted of the following procedures : 1) diethyl ether extraction and chromatographic separation of unconjugated steroids (17-OH-Δ⁵P and 17-OH-Δ⁴ P), 2) enzymatic hydrolysis of 17-OH-z5P-S using the residue of diethyl ether extraction for a material, 3) diethyl ether extraction and chromatographic purification of hydrolyzed 17-OH-Δ⁵P-S, and 4) RIAs for 17-OH-Δ⁵ -Pto estimate 17-OH-Δ⁵P and 17-OH-Δ⁵P-S concentration, and for 17-OH-Δ⁴P.
Extracted 17-OH-Δ⁵P was well separated from 17-OH-OΔ⁴P by Sephadex LH-20 microcolumn chromatography, using a benzen/methanol= 95/5 (v/v) solvent as a mobile phase.
Several procedures for hydrolysis or solvolysis of 17-OH-Δ⁵P-S were compared using available tritiated Δ⁵-3β-hydroxysteroids including dehydroepiandrosterone (DHA), DHA sulfate (DHA-S) and 17-OH-Δ⁵5P, and it was found that the most suitable method was an enzymatic hydrolysis by arylsulfatase from Helix Pomatia in an appropriate condition in which the percent hydrolysis was 92.9 ± 1.2 (mean ± SEM)%.
The final percent recoveries were 88.7 ± 1.2% in 17-OH-Δ⁴ P, 90.7 ± 1.4% in 17-OH-Δ⁵P and 78.1 ± 2.1% in 17-OH-Δ⁵P-S, respectively.
A suitable antiserum and its final dilution titer for RIA of 17-OH-Δ⁵P (hydrolyzed 17-OH-Δ⁵P-S also) was 1:12,000 dilution of anti-17-OH-Δ⁵P-3-succinate-BSA serum. An anti-7-oxo-17-OH-Δ⁵P-7-carboxymethyloxime-BSA serum was considered to be unsuitable for the measurement of hydrolyzed 17-OH-Δ⁵5P-S, presumably because of a significant cross-reactivity with a large amount of unknown steroid sulfates simultaneously hydrolyzed.
The fact that concentrations of the steroids estimated by this method were well in agreement with those previously reported by other authors and that the precision and accuracy of this method were both satisfactory indicates the availability of this combined RIA method for the elucidation of developmental changes in the activities of 3β-HSD and SK in infancy and childhood.

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There are many reports of glucose intolerance in adult patients with hyperthyroidism but few reports of glucose intolerance in hyperthyroid children. In this study, we measured plasma levels of glucose, insulin, glucagon and growth hormone in hyperthyroid children and control subjects by the use of three kinds of tolerance tests : an oral glucose tolerance test, an arginine tolerance test and an insulin tolerance test. In the oral glucose tolerance test, mean fasting glucose levels (79.6 ± 1.4 mg/dl) rose to maximum levels (157.3 ± 4.3 mg/dl) at 30 min in hyperthyroid children which were significantly higher than the levels in control subjects (p<0.01). The maximum levels of glucose fell slowly and returned to fasting levels at 180 min. In this test, plasma insulin levels increased from basal levels (12.7 ±1.9 μU/ml) to maximum levels (120.8± 22.1.μU/ml) at 30 min in the prepubertal age group of hyperthyroidism. On the other hand, in the pubertal age group of hyperthyroidism, maximum levels of insulin were observed at 60 min, but not at 30 min. These maximum levels of insulin of both hyperthyroid age groups were significantly higher than those in the control subjects (p<0.05, p<0.01 respectively). There was no difference in insulin-glucose ratio at 30 min (ΔIRI/ΔBG) and insulinogenic index (I.I.) at 0 to 60 min between these two groups of hyperthyroid children and control subjects. However, I.I. at 0 to 120 min and 0 to 180 min decreased significantly in the pubertal age group of hyperthyroidism as compared with those in the control group (p<0.05, p<0.02 respectively). In the oral glucose tolerance test, plasma glucagon levels decreased from basal levels (74.1 ± 4.3 pg/ml) to minimum levels (36.4 ± 4.7 pg/ml) at 90 min in hyperthyroidism, which were significantly lower than those in the controls (p<0.05). However : there was no difference in -ΣΔAIRG/ΣΔBG (cummurative glucagon response/cummurative glucose response) between the subjects with hyperthyroidism and the controls. On the other hand, lower responses of blood glucose, insulin, glucagon and growth hormone to arginine were observed in subjects with hyperthyroidism than in the controls.
Moreover in the insulin tolerance test, there was no difference in glucagon and growth hormone response between the subjects with hyperthyroidism and the controls.
Thus our conclusions are as follows : 1) A marked increase in blood glucose after oral glucose load was observed in spite of normal insulin-glucose ratio in hyperthyroid children, suggesting the existence of peripheral insulin resistance. 2) In the pubertal age group, as indicated by the decrease of LI., insulin insufficiency may also be responsible for glucose intolerance in hyperthyroidism. 3) Adequate suppression of glucagon to oral glucose load was observed in the subjects with hyperthyroidsm and the controls, suggesting that there is no difference in pancreatic A-cell sensitivity to glucose between hyperthyroidism and controls. 4) Lower responses of insulin and glucagon to arginine in the subjects with hyperthyroidism compared with those in the controls were observed, suggesting that the islets of Langerhans are insensitive to arginine in hyperthyroidism. 5) Adequate growth hormone response to insulin-induced hypoglycemia was observed in the subjects with hyperthyroidism, suggesting that growth hormone is secreted normally.

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The image diagnoses of a case of so-called “nonfunctioning” adrenal adenoma, weak mineralocorticoids producing adrenal carcinoma, congenital adrenogenital syndrome due to 21-hydroxylase deficiency-simple virilizing form-, and 5 cases of pheochromocytoma were studied.
In a patient with so-called “nonfunctioning” adrenal adenoma (2.3 × 3.0 × 3.3 cm), in which steroids biosynthesis was confirmed, computed tomography (CT) delineated the tumor shadow with extremely low density, and ultrasonography (US) demonstrated the round tumor echo with homogenous and low echogenicity at the superior region of the right renal pole. Adrenal scintigraphy also showed the tumor image.
A weak mineralocorticoids-producing left adrenal carcinoma (3.5 × 3.5 × 3.0 cm) was shown as a heterogenous round tumor at the left lateral portion of the vertebra by CT. On adrenal scintigraphy under dexam, ethasone pretreatment, there was good uptake in the tumor and disappearance of the contralateral.
Both bilateral adrenal images on CT in a patient with congenital adrenogenital syndrome were linear-shaped and markedly enlarged. The enlarged right adrenal was clearly demonstrated by US with an electronic sector scanner but not with an electronic linear scanner, although the left one was hardly shown by either US instruments.
Three of 4 patients with pheochromocytomas examined by US were correctly detected, while in the remaining one the tumor image was judged to be a retroperitoneal tumor. CT also correctly demonstrated the former 3 pheochromocytomas, but misjudged the latter one as a pancreatic cancer. Good uptake of Adosterol^® by bilateral adrenals was shown in a case of extra-adrenal pheochromocytoma. Three of 4 cases of adrenal pheochromocytoma showed the isotope uptake of the contralateral normal adrenal alone. In another case of right adrenal pheochromocytoma, isotope accumulation in the colon obscured whether the isotope uptake in the right adrenal was shown or not.

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In a previous study, we showed that the percentage of peripheral K cells of patients with subacute thyroiditis (SAT), determined by a plaque-forming cell technique, was significantly lower than that of normal controls, and that the sera from SAT significantly inhibited the activity of K cells in normal lymphocytes, suggesting that in the sera of SAT there is some factor which inhibits K cell activity.
In this study, we investigated the relationship between K cells and the serum immunosuppressive acidic protein (IAP), the sex difference in percentage of K cells, and the absolute count of K cells in patients with SAT.
In normal controls, there was a sex difference in the percentage of K cells in total lymphocytes; the percentage was significantly lower in women (mean ± S.D., 5.0 ± 2.0%; n= 12; <0.01) than in men (8.4 ± 2.9%; n= 20). However, there was no sex difference in the absolute count of peripheral K cells.
In the acute phase of SAT, the percentages of K cells were 2.4 ± 1.8%, 2.4 ± 1.9% and 2.7 ± 1.0% in 19 patients, 16 females and 3 males, respectively, which were significantly lower than 6.8 ± 3.0%, 5.0 ± 2.0% and 8.4 ± 2.9% in 25 controls, 12 females and 13 males, respectively. The absolute counts of K cells in the acute phase of SAT were 56 ± 45/mm3 and 58 ± 48/mm3 in 13 patients including 11 females, respectively, which were significantly lower than 165 ± 63/mm3 and 153 ± 73/mm3 in 12 patients including 5 female controls, respectively.
It was observed that serum IAP values in SAT were correlated negatively with the percentage of K cells and positively with the inhibition rate of SAT sera on K cells from normal subjects.
Moreover, purified IAP showed a dose-related inhibition on the K cells from the control subjects. These results suggest that IAP in the sera of SAT seems to be one of the factors which inhibits the activity of K cells.

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To investigate the effects of bromocriptine on the secretion mechanism of pituitary gonadotropins and testosterone, 5 mg of bromocriptine was administered to five young adult men who were normal in their endocrinological states. Blood samplings were taken from two hours before until six hours after the administration every 15 min., and after that, blood samplings were continued until 21 hours every one hour by an intravenous indwelling catheter. Serum FSH, LH, prolactin and testosterone levels were determined by RIA, and the changes of the pulsatile patterns of FSH and LH, and the circadian profile of these hormones by the administration of bromocriptine were analysed.
Serum prolactin levels decreased significantly (p<0.005) from two hours after the administration of bromocriptine and remained in a very low range until the end of the experiment. The basal levels of FSH showed a significant decrease from two to six hours after the administration (p<0.005). Also the basal levels of LH showed a significant decrease from two to six hours after the administration (p<0.005). However, the basal levels of serum FSH and LH did not show significant decreases after that until the end of the experiment. No significant change was observed in the amplitude or the frequency of the pulsatile patterns of FSH and LH until six hours after the administration of bromocriptine. The serum levels of testosterone were also significantly decreased from two to six hours after the administration (p<0.005), but they did not show a significant decrease after that until the end of the experiment. The circadian profile of serum prolactin levels showed a significant rise during 20 to 23 o'clock (p<0.005) and 4 to 8 o'clock (p<0.005) in the control group. With the administration of bromocriptine, however, these nocturnal surges of prolactin diminished. There was no conspicuous circadian profile in serum FSH and LH levels in either the control or the bromocriptine administered group. But in serum testosterone levels, there was an obvious circadian profile. The basal levels of serum testosterone during 18 to 21 o'clock were significantly lower than those of 6 to 9 o'clock both in the control group and in the bromocriptine administered group (p<0.005, p<0.005). From these facts it is suggested that bromocriptine acts mainly on the pituitary rather than the hypothalamus to decrease the serum levels of gonadotropins, and it may also play some role in the steroidogenesis of the testis. However, the action of bromocriptine which decreases serum gonadotropins or testosterone seems to be moderate.

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