Peroxidase activity in thyroid tissue from 25 patients with Graves' disease was measured by Mini assay method (J. Biochem. 98,637-647, 1985) employing guaiacol or iodide as a second substrate. The mean values of protein-based specific activity were 0.496 guaiacol unit/mg protein and 0.187 iodide unit/mg protein, reaching 16 fold and 28 fold those of normal thyroids, respectively. The mean value of ratio of iodide unit to guaiacol unit in each thyroid, 0.68, was also much higher than that of normal human thyroid, 0.16. No significant difference in peroxidase activity was observed between patients treated with methylmercaptoimidazole and those with propylthiouracil, but the activities of those groups were significantly higher than those of patients treated with potassium iodide, suggesting that inorganic iodine therapy plays some role in suppressing the synthesis of thyroid peroxidase in Vitro.

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Serum thyroglobulin (Tg) levels were measured in 15 normal volunteers, 69 patients with differentiated thyroid carcinoma, 22 with adenoma, 45 with adenomatous goiter, 5 with functioning adenoma and 24 with Graves' disease, utilizing a double antibody radioimmunoassay technique.
Serum Tg levels in the normal volunteers were found to be less than 30 ng/ml as determined from their mean value, i.e., 16.9 ±13.4 ng/ml (mean + 2SD), whereas serum Tg in the patients with various thyroid disorders showed significantly elevated (P<0.01).
Serum Tg of patients with differentiated thyroid carcinoma without distant metastasis was 71 ±7 ng/ml (mean ±SE), that in adenoma 124 ±22 ng/ml, that in adenomatous goiter 147 ±19 ng/ml, that in functioning adenoma 120 ±41 ng/ml, and that in Basedow disease 122 ±22 ng/ml. Furthermore, it appears that Tg concentration in serum is correlated with the size of the nodules in differentiated thyroid carcinoma (P<0.01) and benign nodules (P<0.05).
Present results suggest that thyroid tumor also release Tg into serum in addition to Tg stored in the normal tissue. Furthermore, the level of circulating Tg in patient is not correlated to the level of serum TSH.
In treated differentiated thyroid carcinoma, serum Tg levels were markedly reduced. (21 ±2 ng/ml) in patients with no evidence of either recurrences or metastases, but significantly elevated in those with recurrences and/or metastases (257 ±109 ng/ml). Therefore, serum Tg measurements in the follow-up of patients treated for differentiated thyroid carcinoma are useful in the search for recurrences or metastases.

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Aromatization of C-19-steroid (androstenedione;Δ⁴ A) and C-19 norsteroid (19- nortestosterone; NT) was measured in human placenta, liver and adipose tissues. The tissue homogenates (0.5-1.0 g w.w.) were incubated with [6, 7-³1-1] -Δ⁴ or [6, 7-³H] -NT (10 μCi) and NADPH (1 mg/ml of 0.1M-bisodium phosphate buffer) at 37°C for 2 hr in air. The enzyme reaction was terminated with 3 volumes of ethyl acetate, and [4-¹⁴C] -estrone (El) and [4-¹⁴C] -estradiol-170 (E₂) (10,000 dpm, 250μg) were added in the incubated sample. The extract with ethyl acetate was subjected to Bio-Rad AG1-X2 column chromatography. The phenol fraction thus obtained was subjected to thin layer chromatography (TLC) (cyclohexane-ethyl acetate = 2 : 1, V/V and chloroform-ethyl ether = 4 : 1, V/V). The resulting E₁ and E₂ were finally isolated by co-crystallization to constant specific activity and ³H/¹⁴C ratio of crystal crops.
In human placental microsomes, estrogen formation from Δ⁴A and NT was 8.10 and 1.84 pmol E₁ + E₂/hr/mg protein, respectively. In adult liver homogenates, only E₁ (35-76 fmol/hr/g) was formed from Δ⁴ A, but E₁ and E₂ were formed (70 and 31 61 fmol/ hr/g, respectively) from NT. On the other hand, adipose tissue had the ability to aromatize Δ⁴A to E₁ (38 - 69 fmol/hr/g), but its ability to aromatize NT was significantly lower than that for Δ⁴ A. These results show that NT is readily aromatized to estrogens in the liver.

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The purpose of this study is to clarify the role of renal dopamine receptor in the pathogenesis of salt-dependent hypertension. Male Wistar rats were raised under three different conditions, control, 1% NaCl loading (NaCl) and 1% NaCl plus metoclopramide with a dose of 1.5mg/kg daily (MC), for 2 weeks. Then, renal plasma membranes were prepared by ultracentrifugation method, and maximal binding capacity (Bmax) and dissociation constant (Kd) were determined by Scatchard analysis using 3H-spiperone. And plasma aldosterone and prolactin concentration in these three groups were measured by radioimmunoassay.
Results: Systolic blood pressure measured tail-cuff method significantly elevated in MC group, but not control and NaCl group. Bmax of renal dopamine receptor was 535.9 ± 85.0 fmol/mg protein, 594.9 ± 159.3 fmol/mg protein, 529.1 ± 166.1 fmol/mg protein, in control, NaCl and MC group, respectively. Kd of renal dopamine receptor in NaCl group was significantly lower than control (p<0.05). Renal dopamine contents of NaCl and MC group were lower than control. There was a negative correlation between renal dopamine content and Bmax of renal dopamine receptor in NaCl group (r = - 0.95, p<0.02). In MC group, plasma aldosterone concentration was slightly higher than control and NaCl group,but there was no differences in Plasma prolactin concentration among these three groups.
Conclusion: These data suggests that renal dopamine receptor may participate in sodium transport in kidney, and that the impairment of dopaminergic activity may cause sodium-dependent hypertension.

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Corticotropin-releasing factor (CRF), a hypothalamic releasing hormone, is now known to be widely distributed in extrahypothalamic tissues such as the pancreas and gastrointestinal tract. There are, however, no data concerning the development of CRF in the gastrointestinal tract in immature animals. Using a specific RIA technique for rat CRF, we have determined the IR-CRF concentrations in acid extracts of hypothalamic, pancreatic and gastrointestinal tissues in immature rats. Gel filtration of the extracts was also under-taken in order to investigate the molecular characteristics of the IR-CRF in the digestive system.
Pregnant rats were decapitated at 20 days of gestation and the male fetuses (1 day before birth) were removed by hysterotomy. The male pups were also killed by decapitation immediately after birth and at 1, 3, 7, 14, 21, 28 and 42 days postnatally. The rats older than 3 days were divided into fed and 15-h-fasted groups. Pups were weaned at 21 days. The hypothalamus, pancreas, gastric antrum, duodenum and proxymal jejunum were removed immediately after decapitation. The individual tissue fragments were homogenized in 2N acetic acid and boiled for 5 min. The homogenates were centrifuged at 15,000g at 4°C for 30 min and supernatants were removed, lyophilized and stored frozen until assay.
Gel filtration was performed at 4°C on a Sephadex G-50 (fine) column (1.6 × 82cm).A 3 ml of sample was applied to the column and eluted with 0.2N acetic acid containing 0.25% BSA. Fractions of 3 ml were collected and stored at - 20°C until assay.
The reagents for RIA were purchased from Peninsula Lab., INC. (Belmont, CA.). ¹²⁵ I-Tyr°rat-CRF was labelled by chloramine-T method. Rabbit anti-CRF serum was used at the final dilution of 1 : 33,000. The antigen bound antibody was separated from the free antigen by the double antibody method using goat anti-rabbit IgG serum. The sensitivity of this RIA was 2-4pg/tube. The average coefficients of variation for interassay and intra-assay were 11.2% and 9.0%, respectively.
Extracts of the pancreas, duodenum and jejunum of immature rats gave dilution curves that were parallel to the rat CRF standard curve as well as that of the hypothalamus. IR-CRF from extracts of the hypothalamus of one- and 42-day-old rats coeluted with synthetic rat CRF on Sephadex G-50 gel chromatography, and those from extracts of the pancreas and jejunum of one-day-old rats and that of the duodenum of 42-day-old rats also coeluted with synthetic rat CRF. These findings suggest that peptide very similar to rat hypothalamic CRF is present in these tissues.
The mean hypothalamic IR-CRF concentration was 5.5 ± 3.5ng/g wet weight of tissue one day before birth and remained almost constant during the first week of life. Then it increased gradually by about threefold up to day 21.
The mean IR-CRF concentrations in the pancreas and jejunum were very low before birth. But they increased abruptly immediately after birth and reached the levels about four times higher than that in the hypothalamus. Thereafter, they declined progressively with age.
On the other hand, the mean IR-CRF concentrations in the gastric antrum and duodenum were much lower than that in the hypothalamus throughout maturation.
No significant difference was seen between the fed and 15-h-fasted rats in any age group except that in the pancreas at day 3.
These findings show : 1) that IR-CRF present in the pancreas and gastrointestinal tract is similar to hypothalamic CRF in the immature rats, and 2) that mean IR-CRF concentrations in the pancreas and jejunum had very high peaks, while that in the hypothalamus remained constant in the early neonatal period. Therefore, these findings also suggest that CRF in the pancreas and jejunum may play a particular role in the neonatal rats.

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Determination of plasma IGF-I concentrations is not easily accessible to clinical use at present because of extremely limited supply of purified natural IGF-I essential for its assay system. Thus, an alternative method has recently been introduced by the development of a specific radioimmunoassay (RIA) for IGF-I (26 - 46).
We examined the specificity and sensitivity of this assay system, and then investigated the changes in plasma concentrations of IGF-I in normal children, adults and in patients with various endocrine and metabolic diseases. Each plasma sample was subjected to acid-ethanol treatment before assay to separate IGF-I from its binding protein.
The recovery rate of known amount of IGF-I (26 - 46) added to untreated plasma sample was more than 90%. The coefficients of variation of intra- and interassay were 9.0% and 13.6%, respectively. This assay system was able to detect IGF-I as low as 10pg/tube. When plasma sample of a patient with active acromegaly was applied to Sephadex G-75 column, immunoreactive IGF-I was eluted at the position of 7,000 molecular weight. An inhibition curve of plasma extract from an acromegalic patient was parallel to that of IGF-I (26-46), indicating that the RIA could detect IGF-I. There was no remarkable difference between IGF-I values of plasma and serum from the same individual.
The value of IGF-I concentration of cord plasma was considerably low (144 ± 6.7pg/ ml, M ± SEM) as compared with that of sera of 49 normal children aged 7 - 12 years (320 ± 14.3 pg/ml). The highest value (460 ± 54pg/ml) was attained at the age of 13 years, followed by gradual decrease toward adult age. Plasma IGF-I concentration of normal adults between 20 and 69 years of age was 290 ± 10pg/ml. When plasma IGF-I values of adult males and females were separately plotted against age group of each decade, the value declined gradual-ly with age in males while in females there was a remarkable increase in plasma IGF-I concentration at 4th and 5th decades, suggesting the effect of hormonal change at menopause on plasma IGF-I levels.
There was a good correlation between disorders of GH secretion and plasma IGF-I concentrations. In 10 cases of active acromegaly the level was 506 ± 67pg/ml (285 - 970pg/ ml). On the other hand in 20 patients with pituitary dwarfism it was only 180 ± 15pg/ml. In one patient with pituitary dwarfism plasma IGF-I concentrations were determined before and 3 successive days after intramuscular administration of 8U hGH. While plasma GH level reached the peak at 6 hours after the administration, plasma IGF-I rose from low value of 140pg/ml to normal value of 315pg/ml at 48 hours.
Plasma IGF-I levels of 36 patients with type II diabetes mellitus were correlated only with HbA1, but not with the degree of obesity and with the presence or absence of retinopathy.
In patients with liver diseases, concentrations of plasma IGF-I showed tendency to decline in proportion to the degree of impaired liver function. Low levels of plasma IGF-I was also noted in patients with malignant diseases.
These results indicate that the RIA for IGF-I (26-46), presented in this study, is a specific and sensitive assay system and a useful tool for determination of plasma IGF-I concentrations until full molecule IGF-I and its specific antibody become easily available.

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