We studied 17 short prepubertal children, aged 7.5 to 17.0 years (mean±SD: 11.7±2.4) more than 2.0 SD below the mean height for their age and of delayed bone age (M±SD: 8.1±2.3), to clarify their physiological GH secretory status. The mean concentration of GH (MCGH) was calculated and was compared with the subjects' GH responses to insulin and arginine tolerance tests (IATT) and plasma somatomedin-C (SM-C). The mean 24-h MCGH value was 3.2±1.3ng/ml (range 1.6-5.5). The mean peak GH response to the IATT was 13.0±7.5 ng/ml (range 2.4-33.9). In addition to the two patients with abnormally low GH responses to the IATT, seven with normal responses showed low 24-h MCGH values, a small number of GH pulses and low mean GH amplitude. The mean plasma SM-C in all patients was 0.60±0.20 U/ml. This was significantly lower than that of age-matched children of normal height (p<0.001). The 24-h MCGH was significantly correlated with plasma SM-C levels (r=0.51, p<0.05) and with that of the first three hours of sleep at night (r=0.84, p<0.01).
These results indicate that: 1) some short children with normal GH response to pharmacological tests secrete a low amount of GH physiologically and 2) blood sampling during the first three hours of sleep as well as 24-hour sampling is suitable in evaluating the physiological secretion of GH.

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The roles of human low density lipoprotein (LDL)-cholesterol and high density lipoprotein (HDL)-cholesterol on adrenal steroidogenesis were investigated using cultured human adult and fetal adrenocortical cells and the findings were then compared to those obtained with bovine adrenocortical cells.
The secretion of cortisol in both human and bovine adrenocortical cells was dose-dependently increased by the administration of LDL-or HDLcholesterol in the presence of adrenocorticotropin (ACTH). LDL-cholesterol was utilized to a greater extent than HDL-cholesterol in both human and bovine adrenal steroidogenesis in the presence of ACTH. Exogenous lipoproteinderived cholesterol was less utilized in human adrenal steroidogenesis than in bovine adrenal steroidogenesis, compared to the endogenous cholesterol.
An increase in the secretion of cortisol and dehydroepi androsterone sulfate (DHEA-S) continued for the 5-day culture period, in the presence of lipoprotein cholesterol and ACTH in both human adult and fetal adrenocortical cells. The secretion of aldosterone increased on the first day of the culture period, then gradually decreased for the 5-day culture period in human adult adrenocortical cells, but not in human fetal adrenocortical cells in the presence of lipoprotein cholesterol and ACTH.
These findings demonstrate that exogenous cholesterol utilized in the biosynthesis of steroids is mainly from LDL-cholesterol in both human adult and fetal adrenals and bovine adrenal and the proportion of cholesterol synthesized de novo is significantly larger in the human adult adrenal than in the bovine adrenal.

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We examined the utilization of human low density lipoprotein (LDL)-and high density lipoprotein (HDL)-cholesterol for steroid production in primary monolayer culture cells from adenomas of primary aldosteronism and Cushing's syndrome and an adrenal of nodular hyperplasia of Cushing's syndrome. We compared the data obtained with findings in the case of cultured normal human adrenocortical cells. In the presence of 10-7 M adrenocorticotropin (ACTH), the addition of either LDL or HDL to the culture medium at a cholesterol concentration of 100μg/ml led to a significant increase in the daily secretion rates of cortisol, dehydroepiandrosterone sulfate (DHEAS) and aldosterone in the adenoma and nodular hyperplasia cells, as in the normal cells. Although LDL greatly increased the secretion of steroid hormones, no significant difference in steroid secretion following the treatments with LDL and HDL were observed in these cultured cells. The contribution of endogenous cholesterol to steroid production was also high, thereby indicating that the neoplastic transformation did not have untoward effects. Cells from adenomas of primary aldosteronism secreted not only aldosterone, but also cortisol and DHEA-S. The daily secretion rates of these steroids were markedly increased when ACTH was added to the medium. With prolonged exposure to ACTH, however, the rate of aldosterone secretion showed a gradual decrease with the incubation time. This decrease might be due to the impaired conversion of corticosterone to 18-hydroxycorticosterone. In case of adenomas in patients with Cushing's syndrome, the secretion of steroid hormones varied in quantity and quality, depending on the type of plasma cortisol response to the rapid ACTH test in vivo, thereby suggesting that the adrenocortical adenoma of Cushing's syndrome might be divided into two subtypes. These results indicate that human functioning adrenocortical adenoma cells utilize plasma lipoproteins as a source of cholesterol for steroidogenesis during the prolonged stimulation of steroid secretion.

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In order to examine the effects of a-human atrial natriuretic polypeptide (α-hANP) on the basal plasma concentrations of GH, TSH, LH, FSH and PRL in humans, synthetic α-hANP was infused into 10 normotensive, euvolemic, healthy volunteers. There were observed marked hypotensive, diuretic and natriuretic effects during the α-hANP infusion. The basal plasma concentrations of GH, TSH, LH and FSH, showed no significant change following the α-hANP infusion. However, significant suppression of the plasma PRL concentration was observed with the α-hANP administration. The mean plasma PRL concentration tended to be decreased during 20 min of α-hANP infusion, however, there the differences were not statistically significant. A significant reduction in the mean plasma PRL concentration (-20%, P<0.5) was observed 10 min after the end of infusion, following the reversion to the preinfusion level at 70 min after the end of infusion. Such a significant and delayed suppression was not seen in the case of placebo infusion. The data suggest that the circulating hANP may reduce the release of PRL.

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In order to elucidate the mechanism of suppression of plasma aldosterone by chronic ACTH administration, especially the role of the renin-angiotensin system and dopamine, we administered ACTH with or without MK422, a converting enzyme inhibitor, to reduce the endogenous angiotensin II in rats, and measured the plasma renin activity, plasma corticoid concentrations and urinary dopamine excretion. The plasma aldosterone concentration (PAC) was decreased after chronic ACTH administration. However, in the ACTH+ MK422 administered group, aldosterone suppression was not observed. It appeared therefore that the aldosterone suppressing mechanism was independent of the weakened renin-angiotensin system following chronic ACTH administration, since PAC was not decreased in the ACTH+ MK422 administered group when angiotensin II might be completely eliminated. The urinary excretion of dopamine was significantly increased in the chronic ACTH+MK422 administered group as well as in the chronic ACTH administered group. This suggested that the inhibitory effect of dopamine on aldosterone did not contribute significantly to the suppression of plasma aldosterone.
The present results suggest therefore that the mechanism of suppression of plasma aldosterone following chronic ACTH administration was not dependent on the renin-angiotensin system and dopamine.

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To clarify the possible direct effects of hyperprolactinemia on the ovulatory process, we experimentally established hyperprolactinemia in female rabbits with 4 daily injections of sulpiride (SLP) at different doses and induced ovulation with human chorionic gonadotropin (hCG). Plasma levels of prolactin (PRL) were increased significantly before hCG injection in each SLP-treated group compared with the corresponding values for the controls. The ovulation rates at 14 h after hCG were significantly reduced in the 16 and 24mg/kg/day SLP-treated groups. An inverse correlation (r=-0.74, P<0.001) was found between the ovulation rate and the increasing in plasma PRL measured just prior to hCG injection. The increase in peripheral as well as ovarian venous progesterone and 20α-hydroxypregn-4-en-3-one (20α-OHP) at 4 and 14 h after hCG injection in inhibited ovulation groups was much less than in the control group. However, the estradiol, androstenedione and testosterone concentrations were comparable with the control values. These results indicate that hypersecretion of PRL induced by SLP has a direct effect on ovary by inhibiting follicular rupture induced by hCG and this inhibitory effect was partly due to the suppression of progesterone secretion during the course of ovulation.

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HLA-A, -B, and-C antigen frequency of 61 Japanese patients with Graves' disease, and HLA-DR and-DQ frequency of 53 patients with it were compared that of 1, 998 controls. The prevalence of Bw46 was significantly higher in patients with Graves' disease (23.0% vs 8.4%, Pc <0.003). The result was quite different from previous reports on Japanese Graves' disease.

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The pathophysiological role of thyroid blocking antibody (TBAb) in patients with adult primary hypothyroidism and the mechanism of TBAb action were studied.
A sensitive bioassay for TBAb, which inhibits the TSH-induced cAMP accumulation, was established using normal human thyroid cells in culture.
Thirty-four patients with primary hypothyroidism consisting of 17 goitrous and 17 non-goitrous patients were examined. Two out of 17 goitrous patients (11.8%) and three out of 17 non-goitrous patients (17.6%) were TBAb positive. There were no significant differences between TBAb positive and negative patients in terms of the severity of hypothyroidism or the titers of MCHA or TGHA.
Four out of the five TBAb-positive IgGs had strongly positive thyrotropin binding inhibitor immunoglobulin activities. All five TBAb-positive IgGs inhibited the cAMP increase induced by Graves' IgG, but did not affect the action of either prostaglandin E1 or cholera toxin. However, three TBAb positive IgG also inhibited the cAMP increase induced by forskolin.
These findings indicate: 1) TBAb is present in hypothyroid patients with autoimmune thyroiditis and TBAb may play a role in the pathophysiology of these patients. 2) TBAb may inhibit the action of TSH not only at the level of the TSH receptor, but also at a different site from the TSH receptor.

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Twenty-two women with hyperprolactinemia and amenorrhea were followed up for at least 18 months after 22 bromocriptine-induced full term pregnancies. Return of menstruation occurred in 9 of the 22 patients after pregnancy. Five of them conceived subsequently without any treatment. The prolactin (PRL) concentration before or during bromocriptine treatment was not significantly different between the patients who conceived spontaneously and those who did not. However, the PRL concentration after weaning was significantly lower in the patients who conceived spontaneously than in those who did not. Serum PRL levels were normal or only slightly elevated in the patients who conceived spontaneously.
In 11 of the 22 patients, PRL levels were serially determined during bromocriptine-induced pregancies. In 7 of the 11 patients, serum PRL levels fellduring the second or third trimester. Spontaneous pregnancy occurred in 3 of the 7 patients who showed a decrease in PRL values during pregnancy, but in none of the 4 patients who did not. Furthermore, PRL levels after weaning correlated with PRL levels during the third trimester in these 11 women. Consequently, a decrease in PRL values during pregnancy may result in a fall in PRL levels after pregnancy, which in turn leads to the restoration of reproductive function in some subjects.

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The effect of the suckling stimulus on pulsatile luteinizing hormone (LH) secretion in mid-and late lactation (days 10 and 20 of lactation) in rats was examined. Pulsatile LH secretion was strongly suppressed on either day 10 or 20 of lactation in intact rats in which the baselines of LH secretion were kept very low. In ovariectomized rats the baseline was kept as low as was observed in intact rats on day 10 of lactation, and pulsatile LH secretion was observed in 3 out of 6 rats. On day 20 the baseline secretion increased and pulsatile LH secretion was observed in 5 out of 6 rats, and the baseline for each rat showed various levels. These results clearly indicate that the pulsatile LH secretion was strongly suppressed until ovulation occurred on day 18-23 of lactation in intact rats and suggest that suppression of pulsatile LH secretion by the suckling stimulus at the hypothalamo-pituitary level is removed in late lactation and the time of the removal varies from animal to animal.

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Basic properties of the binding of [¹³¹I]-labeled rat FSH ([¹³¹I] rFSH) to the testicular homogenates of fetal rats were analyzed by micro-radioreceptor assay. Specific binding of FSH was detectable in the testicular preparations from 15.5-day fetuses, but it was very low. After 17.5 days of gestation, specific FSH binding was apparent in the testis and was effectively displaced by rat FSH but not by rat LH. The Scatchard plot analyses of the binding of FSH to the testicular preparations of fetuses showed straight lines similar to those of postnatal rats, suggesting the presence of a single class of binding sites. The mean dissociation constant (Kd) for FSH receptors in 17.5-day fetuses was 0.413±0.043 nM, which was significantly greater than that in postnatal rats at 50 days of age. However, the Kd in 19.5-day fetuses was not significantly different from those in 17.5-day fetuses and postnatal rats due to its considerable variance. The capacity of FSH binding sites was 0.51±0.01 fmol/testis in 17.5-day fetuses, which was significantly less than those of 19.5-day fetuses and postnatal rats.

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We investigated cholecystokinin (CCK) receptors on isolated gastric chief cells from guinea pig. CCK stimulated pepsinogen secretion from chief cells at the same effcacy as that induced by carbamylcholine. Binding of ¹²⁵Ilabeled CCK-33 (¹²⁵I-CCK) to chief cells was tempepature-dependent, and was saturable and reversible at 37°C. Hofstee plots of the ability of CCK-8 to inhibit binding of ¹²⁵I-CCK showed a linear regression line, suggesting that CCK receptors possessed one binding site. The dissociation constant of the binding site was calculated to be 3.8×10^-10 M. The dose-response curve of CCK for pepsinogen secretion was superimposed on that for the binding to its receptors. These results indicated that gastric chief cells from the guinea pig possess CCK receptors that relate closely to the action of CCK involved in pepsinogen secretion.

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In order to detect the portion of the angiotensin II molecule binding to the human arteriolar receptor, angiotensine II-(1-5)-pentapeptide, angiotensin II-(1-4)-tetrapeptide and angiotensin II-(1-3)-tripeptide were infused intravenously as saline solutions into the same 5 normal men from 0900 h at a rate of 30 nmol (20 μg)/kg min (1.2 ml/min) for 15 minutes, at a rate of 90 nmol (54.5μg)/kg·min (3.0ml/ min) for 6 minutes and at a rate of 140 nmol (54.5μg)/ kg· min (3.0 ml/ min) for 6 minutes, respectively, on different occasions. At the end of the infusions average increases in blood pressure were 20/22 mmHg (p<0.001) and 6/7 mmHg (p<0.001), respectively, with the former 2 peptides, while the last peptide showed no pressor action at all. It had previously been found by our research group that angiotensin III, angiotensin II-(3-8)-hexapeptide, angiotensin II-(4-8)-pentapeptide, angiotensin II-(2-7)-hexapeptide, angiotensin II-(1-7)-heptapeptide and angiotensin II-(1-6)-hexapeptide have some pressor action but that angiotensin II-(5-8)-tetrapptide has no pressor action in normal men. When these previous results are combined with the present result, it is evident that only tyrosine-containing molecules show pressor activity and that tyrosine-deleted molecules do not show pressor activity at all. It is concluded that tyrosine in position 4 is the key amino acid for the binding of angiotensin II to human arteriolar receptor.

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Postprandial glycaemic and hormone responses to meals with different nutrient compositions and their heterogeneity were evaluated in 16 non-insulindependent diabetic patients and 5 healthy volunteers. Five kinds of nutrient stimulation-75 g glucose, a Japanese mixed meal (400 kcal, carbohydrate 60%, protein 14%, fat 26%), a high protein meal (300 kcal, C 26%, P 64%, F 10%), a high fat meal (300 kcal, C 23%, P 5%, F 72%) and 20 giv glucose-was given to each subject. On the average, in both normal and diabetic subjects, the increases in plasma glucose (PG) and insulin (IRI) were the largest with the oral glucose load and the smallest with the high protein meal. The ratio of increase in IRI and PG (ΣΔIRI/ΣΔPG) was the highest with the high protein meal and the lowest with the oral glucose load.ΣΔIRI with the high protein meal and the high fat meal were the same in normal and diabetic subjects. However, each of the 16 NIDDM patients and 5 normal volunteers exhibited a different pattern of response to the nutrient stimuli and no definite subgroup could be classified. There was no correlation between metabolic responses and family history of diabetes mellitus, duration of diabetes, body mass index and fasting plasma glucose.
The present results suggest the nearly intact capacity of insulin secretion in NIDDM in response to a high protein or high fat meal and the difficulty of subclassification in NIDDM according to the glycaemic and hormone responses to the different nutrient stimuli.

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Searching for the best procedure for simultaneous estimation of the anterior pituitary hormones, extraction efficiencies of various media, additives such as urea and triton X-100, and physical treatments such as freezing-thawing (F-T) and sonication, were examined by measuring prolactin (PRL), growth hormone (GH), lutropin (LH), follitropin (FSH), and thyrotropin (TSH) in the extracts. Ethanolic media (60% EtOH) gave high yields of PRL at neutral to alkaline pH, but poor extraction of GH accompanied by a marked loss of its immunoreactivity during storage. Ethanolic media also gave a poor yield of LH even at high pH. Aqueous media like PBS at various pH, 0.1 M acetic acid and distilled water were considerably effective in the extraction of GH, LH, FSH and TSH if they were coupled with F-T and sonication. However, high yields of PRL could not be obtained with these aqueous media even with F-T and sonication. Hartree's 40% EtOH-6% ammonium acetate, pH 5.1, solubilized considerable amounts of glycoprotein hormones, but yielded almost no GH and only a small amount of PRL. The addition of triton X-100 to PBS (pH 7) at 0.1% resulted in the maximum extraction of glycoprotein hormones with homogenization and F-T, but further sonication was necessary for GH and PRL. When the anterior pituitaries were homogenized and frozen-thawed in PBS (pH 7) containing 1 M urea, yields of PRL, GH, LH, FSH, and TSH were maximum, and sonication did not cause any additional extraction, indicating that this procedure, i.e. homogenization and F-T in 1 M urea-PBS, would be the best for the simultaneous estimation of these anterior pituitary hormones.

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Eleven cases of nonfunctioning parathyroid cyst are reported. Ultrasonography revealed the cystic nature of the asymptomatic lump in the neck. Clear watery fluid obtained by needle aspiration and the increased parathyroid hormone concentration in the fluid established the diagnosis. Five patients, four of whom the cysts reappeared after one (3 cases) or seven (1 case) needle aspirations, underwent surgical resection of the cysts. Six other patients were followed conservatively after the aspiration maneuver. In four patients with enough follow-up time for evaluation, the cyst fluid has not reaccumulated 2 and 2 years after only one aspiration, and 1 year after two aspirations. one patient, the cyst reappeared 9 months after the initial aspiration. Simple percutaneous aspiration may be curative in some cases of nonfunctioning parathyroid cysts.

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We report a 46-year-old male patient with a transient thyrotoxicosis that seems to have been caused by hemorrhagic infarction of a cold thyroid nodule. serum level of triiodothyronine was markedly but transiently elevated, while the serum thyroxine level remained within the normal range. The resected nodule, measuring 8×7×5cm, showed extensive degeneration and necrosis with viable follicles left only at the margin of the nodule. A transient thyrotoxicosis due to acute hemorrhagic infarction of autonomously functioning thyroid nodules has already been reported. This case showed that.the phenomenon could occur even in cold thyroid nodules. Its implications were discussed in relation to the high incidence of impaired TSH response to TRH patients with nodular goiter.

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To verify the influence of the protein binding status of steroids adjacent adrenal cells on steroidogenesis, the effect of transcortin, a specific binding protein of cortisol or corticosterone, on adrenocorticotropin (ACTH)-stimulated corticosterone production in monolayer cultured rat adrenal cells studied.
The transcortin in concentration of 5×10^-7 M was loaded with 0, 2.5, 5 and 10 pg/ml ACTH-(1-24), and the cells were incubated for 2 and 4 hours. Since molar concentrations of corticosterone produced in the medium were below the transcortin concentration at all levels of stimulation, proteinunbound corticosterone in the medium may have been largely reduced by the addition of transcortin. However, the total corticosterone production was not influenced by the transcortin added to the medium. It was speculated that protein-unbound steroid within the concentration range modulated by transcortin in the area surrounding the adrenal cells may not affect adrenal steroidogenesis.

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The plasma concentrations of immunoreactive norepinephrine (NE), dopamine (DA), β-Endorphin (β-E), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were determined by RIA and HPLC every 6 h until 72 h after iv administration of conjugated estrogens during the midfollicular phase. The LH level showed a biphasic pattern after the injection of conjugated estrogens, i. e. significant suppression (-50%) for 6-42 h after the injection, followed by a rebound increase with a peak (+85%) at 72 h. The plasma levels of immunoreactive β-E, NE and DA did not change significantly for 72 h after the injection.

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