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Using a highly sensitive bioassay for TSH, in which human thyroid follicles incorporate 125I and release de novo synthesized thyroid hormone into the culture medium, the thyrotropic activities of various hCG preparations were studied. Under the culture conditions employed, bovine TSH (bTSH) was approximately 6- to 9-fold more active than human TSH (hTSH). Highly purified hCG prepared from urine of normal pregnant women (CR 127) had only a trivial thyrotropic activity equipotent to 0.00022 microU bTSH/U hCG or 0.0013 microU hTSH/U hCG (19.7 microU hTSH/mg hCG). Hybrid hCG (AB1ER) also elicited low thyrotropic activity (14.0 microU hTSH/mg), whereas crude hCG had moderate thyrotropic activity (0.041 hTSH microU/U hCG or 127 microU/mg protein). Deglycosylated hCG, a very weak LH/hCG receptor agonist, was the most potent agonist in thyroid follicles (588 microU hTSH/mg protein). hCGs purified from urine of patients with trophoblastic tumors had greater TSH-like activity (37-84 microU hTSH/mg protein) than purified hCG. Asialo-hCG purified from a patient with choriocarcinoma had very potent TSH-like activity (468 microU hTSH/mg). Submaximal doses of bTSH and hCG variants produced additive stimulation of thyroid function. Furthermore, the thyrotropic effect of hCG was inhibited by anti-TSH receptor antibody obtained from patients with myxedema. These in vitro findings suggest that although hCG is reported to exert potent cAMP-stimulating activity on rat thyroid-like cells (FRTL-5) and Chinese hamster ovary cells transfected with hTSH receptor complementary DNA (0.092-0.72 microU hTSH/U hCG), the thyrotropic activity induced by authentic hCG in human thyroid follicles is too weak to cause hyperthyroidism in normal pregnancy. However, hCG produced by some trophoblastic tumors, particularly asialo-hCG, has potent thyrotropic activity sufficient to cause clinically overt hyperthyroidism when produced excessively.

To elucidate the mechanism of decreased 131I uptake by the thyroid gland in patients with subacute thyroiditis and painless thyroiditis, human thyroid follicles were cultured with interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF alpha), and/or interferon-gamma (IFN gamma), and the effects of these cytokines on thyroid function were studied in vitro. When human thyrocytes were cultured in RPMI-1640 medium containing 0.5% fetal calf serum and TSH for 5-8 days, the cells incorporated 125I, synthesized de novo [125I]iodotyrosines and [125I]iodothyronines, and secreted [125I]T4 and [125I]T3 into the medium. IL-1 alpha and IL-1 beta inhibited 125I incorporation and [125I]iodothyronine release in a concentration-dependent manner. The minimal inhibitory effect was detected at 10 pg/ml. Electron microscopic examination revealed a marked decrease in lysosome formation in IL-1-treated thyrocytes. TNF alpha and IFN gamma also inhibited thyroid function in a concentration-dependent manner. Furthermore, when thyrocytes were cultured with IL-1, TNF alpha and IFN gamma, these cytokines more than additively inhibited thyroid function. Although the main mechanism of 131I uptake suppression in the thyroid gland in subacute thyroiditis is due to cellular damage and suppression of TSH release, our present findings suggest that IL-1, TNF alpha, and IFN gamma produced in the inflammatory process within the thyroid gland further inhibit iodine incorporation and at least partly account for the decreased 131I uptake by the thyroid gland in destruction-induced hyperthyroidism.

Isolated porcine thyroid cells were cultured in agarose-coated dishes and allowed to reform follicles with normal polarity. The thyroid cells reaggregated into follicles were compared with cells cultured in monolayer for cAMP responsiveness to TSH and thyroid-stimulating antibody (TSAb). The cells in follicles were sensitive to TSH stimulation and responded to the hormone at concentrations as low as 3.3-10 microU/ml with an increase in cAMP production. In contrast, 10-50 microU/ml TSH were required to elicit a cAMP response in cells cultured in monolayer using identical conditions. cAMP responsiveness to TSAb also was greater in the cells organized into follicles. TSAb was detected in serum from 89.4% of 66 untreated patients with hyperthyroid Graves' disease using thyroid follicles, but TSAb was detected in serum from only 60% of the patients when assayed using cells in monolayer. The assay using thyroid follicles was used to measure TSAb in 27 euthyroid patients who were euthyroid while receiving thionamide therapy and compared with 20-min thyroid 131I uptake after T3 suppression. TSAb was present in 11 of 12 nonsuppressible patients and in 5 of 15 suppressible patients. TSAb was positively correlated with 20-min 131I thyroid uptake. We conclude that thyroid cells cultured in follicles are suitable for measuring TSAb.

The serum levels of somatomedin A, determined by radioreceptor assay, were significantly higher in 57 adult patients with chronic renal failure (X = 2.57 +/- 0.12 U/ml) than in healthy subjects (n = 131; X = 0.77 +/- 0.02 U/ml). A positive correlation was found between somatomedin A and creatinine levels (r = 0.33), but somatomedin A levels did not decrease after hemodialysis. A reduction was only observed after successful renal allografting. Immunoreactive somatomedin A was also found to be increased in patients with chronic renal failure (X = 2.61 +/- 0.21 U/ml), whereas low levels were obtained by the chick bioassay. However, after separating the inhibitory factors from the stimulatory factors by gel chromatography at neutral pH, uremic serum was shown to contain increased levels of somatomedin activity. Although all somatomedin A, determined by different techniques, was present in high molecular forms, the elution pattern differed from that seen in patients with acromegaly.

The pathogenesis of the goiter that is frequently found in patients with acromegaly is not known. Using ultrasonic scanning, we measured thyroid volume in 17 euthyroid patients with acromegaly and examined the relationships among thyroid size, plasma GH and insulin-like growth factor (IGF-I) levels, and serum thyroglobulin (TG) levels. The mean estimated thyroid volume in these 17 patients was 32.8 +/- 15.5 (+/- SD) mL, significantly larger than that in normal subjects (15.4 +/- 3.1 mL), and 64.7% of the patients had multinodular goiter, as identified by ultrasonography. Thyroid volume was positively correlated with plasma GH and IGF-I levels and heel-pad thickness, but not with the serum TSH level. In 7 patients, thyroid volume decreased in association with a decline in plasma GH and IGF-I levels after surgical treatment. The serum TG level was elevated in 7 of the 15 patients in whom it was measured, and the mean value was 51.7 +/- 62.7 (+/- SD) micrograms/L (normal, 12.6 +/- 6.4 micrograms/L). We found no correlations among the serum TG and TSH levels, plasma GH and IGF-I concentrations, and/or thyroid volume. However, serum TG decreased after surgical treatment, just as did plasma IGF-I. These observations together with the results of recent in vitro studies by others suggest that IGF-I is one of the factors involved in goiter formation, but the elevated serum TG levels in acromegaly are controlled not only by IGF-I but also by other factors.

ACTH responsiveness in vitro to synthetic corticotropin-releasing factor (CRF), lysine-8-vasopressin, and cAMP was examined using superfusion of pituitary adenoma tissue and the nonadenomatous tissue from 16 patients with Cushing's disease. Sensitivity of adenomas to lysine-8-vasopressin and cAMP was similar to that of nonadenomatous tissues; however, sensitivity of adenomas to CRF was lower than that of nonadenomatous tissues in 7 of 16 patients. CRF-induced ACTH secretion from adenomas was inhibited by Ca2+-free medium in all instances and by dexamethasone and somatostatin in some. Angiotensins I and II stimulated ACTH secretion from both adenomas and nonadenomatous tissues, while angiotensin Iinduced ACTH secretion was inhibited by angiotensin-converting enzyme inhibitor. These results suggest that the sensitivity of the pituitary corticotroph adenomas to CRF in some patients is low. This may be due to an abnormality of the step(s) before cAMP formation, such as the CRF receptor.

Human ACTH-producing tumor and plasma have been examined by gel filtration and ion exchange chromatography to detect the possible presence of reported multiple forms of immunoreactive beta-endorphin (I-EP) Ion exchange chromatography of I-EP obtained from gel filtration showed four components of I-EP [two major peaks in the positions of EP-(1-31) and EP-(1-27) and two minor peaks in the positions of N-acetyl EP-(1-31) and N-acetyl EP-(1-27)] in two ectopic ACTH-producing lung cancers, and two components of I-EP [the major peak in the position of EP-(1-31) and minor peak in the position of N-acetyl EP-(1-31) in an ectopic ACTH-producing thyroid cancer. Only a single peak in the position of EP-(1-31) was present in plasma from a patient with Nelson's sindrome and a patient with Addison's disease, in the pituitary adenomas from six patients with Cushing's disease, and in the nontumorous pituitary tissues from a patient with Cushing's disease and a patient with acromegaly. These data suggest that the posttranslational processing of EP in human pituitary is different from that in the ectopic ACTH-producing tumor.

The effects of the somatostatin analog octreotide on plasma GH, TSH, and immunoreactive GH-releasing hormone (IR-GHRH) were studied in 10 normal men. After morning sc administration of 50 or 100 micrograms octreotide or placebo, plasma GH, TSH and GHRH were measured frequently for 6 h. Plasma GH or IR-GHRH concentrations did not change after placebo injection, but plasma TSH levels gradually decreased, in conformity with a circadian rhythm during the morning. The mean plasma GH levels after sc injection of 50 or 100 micrograms octreotide declined, and no spontaneous GH pulses occurred for 5 h. Plasma TSH decreased rapidly after both doses of octreotide and was significantly lower than the level after placebo treatment from 90-315 min (P less than 0.05) and 60-360 min (P less than 0.05 or P less than 0.01), respectively. Plasma IR-GHRH levels also were significantly lower from 30-360 min (P less than 0.05) in the group given 100 micrograms octreotide compared with the value in the placebo group. We conclude that octreotide inhibits not only GH and TSH secretion from the pituitary, but also GHRH release from the hypothalamus and/or peripheral tissues. These findings suggest that somatostatin controls GH secretion not only by suppressing pituitary secretion of GH but also by suppressing GHRH release from the hypothalamus.

A human plasma CRH-binding protein (CRH-BP) was identified and characterized by chemical cross-linking of 125I-Tyr-hCRH to human plasma using disuccinimidyl suberate. The apparent mol wt of the cross-linked complex determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography was approximately 43,000. The mol wt was slightly lower in the nonreduced state, suggesting the presence of intramolecular disulfide bonds. Subtracting the mol wt of 125I-Tyr-CRH, the BP appeared to have a mol wt of approximately 38,000. Binding was specific since the appearance of the 43,000 dalton band was not affected by unlabeled ACTH, vasopressin, serum albumin, or gamma-globulin, but was inhibited by unlabeled hCRH dose dependently. Pretreatment of plasma with 0.1 mol/L HCl, 0.01 mol/L NaOH, 10 mmol/L dithiothreitol, or trypsin before cross-linking abolished its ability to bind 125I-Tyr-hCRH. Rat, rabbit, or goat plasma or human cerebrospinal fluid did not bind 125I-Tyr-CRH. It is unlikely that CRH-BP is a CRH receptor, because the estimated mol wt of the CRH-BP is smaller than the reported size of CRH receptors, and the CRH-BP did not bind to ovine CRH. The binding of 125I-Tyr-CRH to CRH-BP decreased in the third trimester of pregnancy, when plasma CRH levels were markedly elevated. However, after dissociating endogenous CRH from the CRH-BP, the binding was almost the same as in nonpregnant subjects. In addition, CRH-BP inhibited CRH-induced ACTH secretion from cultured rat anterior pituitary cells. We conclude that most of the increased plasma CRH found in pregnant women is bound to CRH-BP, and so is inactive, therefore plasma ACTH levels do not increase to above the normal range.

The levels of serum somatomedin peptides were determined with a somatomedin A radioreceptor assay utilizing human placental membranes. Low levels were found in 25 patients with liver cirrhosis and 28 patients with chronic hepatitis with the mean of 0.47 +/- 0.05 and 0.60 +/- 0.04 U/ml, respectively. There was a positive correlation between somatomedin A on one hand and serum albumin, cholinesterase, total cholesterol and thrombotest on the other. There was a negative correlation between somatomedin A and the indocyanine green retention test. These findings confirm earlier results obtained with bioassay.

To study possible adrenergic modulation of pituitary-adrenal responses to insulin-induced hypoglycemia and CRH we examined the effect of nonselective alpha-blockade (phentolamine) and nonselective beta-blockade (propranolol) on plasma ACTH, cortisol, and vasopressin (AVP) responses to hypoglycemia and CRH in five normal men. Infusion of propranolol or phentolamine did not alter basal plasma ACTH or cortisol levels. The propranolol infusion enhanced the stimulatory effect of hypoglycemia on ACTH, cortisol, and AVP secretion and also enhanced the stimulatory effect of CRH on ACTH and cortisol secretion. Infusion of phentolamine inhibited hypoglycemia-induced ACTH and AVP secretion, but had no effect on the stimulatory effect of CRH on ACTH and cortisol secretion. The increments of plasma ACTH and cortisol induced by an almost maximal dose of CRH (1 microgram/kg) were smaller than those induced by hypoglycemia. The propranolol-induced enhancement of the ACTH response to hypoglycemia was almost the same as the ACTH response to CRH alone. From these results we conclude that propranolol may act at the pituitary level to enhance CRH action, rather than AVP action, and that the ACTH response to hypoglycemia may be mediated by hypothalamic alpha-adrenergic activation.

Immunoreactive corticotropin-releasing factor (I-CRF) was measured by radioimmunoassay and immunoaffinity chromatography in human hypothalamus and cerebrospinal fluid (CSF). Dilution curves of I-CRF in the hypothalamus and CSF were parallel to that of synthetic ovine CRF standard. I-CRF content in the hypothalamus was 643 and 281 fmol eq, respectively. I-CRF concentration in CSF was 7.4 +/- 1.1 fmol eq/ml. Sephadex G-75 column chromatography showed the main peak eluted at the position of synthetic CRF.

The effect of alpha-human atrial natriuretic polypeptide (ANP) on adrenal steroidogenesis was studied in human adrenal tissues obtained surgically from four patients with Cushing's syndrome due to an adrenal adenoma and five patients with an aldosterone-producing adenoma (APA). ANP significantly inhibited basal and ACTH (3.4 X 10(-8) M)-stimulated cortisol and aldosterone secretion in both the adenomas and adjacent adrenocortical tissues from patients with Cushing's syndrome. ANP inhibited ACTH-stimulated, but not basal, secretion of cortisol and aldosterone in the adjacent tissues from patients with APA. In addition, ANP significantly inhibited both basal and ACTH-, angiotensin II (10(-6) M)-, and potassium chloride (10 mM)-stimulated secretion of aldosterone from the adenomas of patients with APA. ANP-induced changes in cortisol and aldosterone secretion were accompanied by a decrease in cAMP and an increase in cGMP secretion. These results suggest that ANP may be a possible regulator of cortisol as well as aldosterone secretion in humans, and these effects might be due to concomitant alteration in cyclic nucleotide metabolism.

The effect of FFA on GH-releasing hormone (GHRH)-mediated secretion of GH was examined in six normal young men. Three of the men were infused with 250 ml of a lipid-heparin solution at 1.67 ml/min for 150 min, and the other three were given an equivalent volume of saline in the same manner. Thirty minutes after the start of infusion, 100 micrograms GHRH (the 44-amino acid form) were injected iv, and plasma GH and FFA were measured. One week later, the same men participated in an identical experiment, but the ones who had received lipid-heparin previously were given saline and vice versa. In both experiments, plasma FFA increased to 2.25 +/- 0.16 meq/liter (mean +/- SEM) 60 min after the start of lipid-heparin infusion, whereas FFA levels did not change significantly in the saline-treated group. Mean plasma GH levels reached peak concentrations in both groups 30 min after GHRH treatment. However, the peak GH response when lipid-heparin was given was significantly diminished (8.4 +/- 1.7 ng/ml), compared with the peak response when saline was given (28.9 +/- 7.1 ng/ml). These data suggest that plasma FFA elevations induced by lipid-heparin infusion inhibit GH secretion induced by GHRH.

Pituitary adenomas were obtained from eight of nine patients with Cushing's disease, and the surrounding tissues as well were obtained from six of nine patients. ACTH, beta-lipotropin (beta-LPH), beta-endorphin, GH, TSH, LH, and PRL concentrations in these tissues were determined by RIA. Immunoreactive ACTH and beta-endorphin (beta-endorphin + beta-LPH) were present in high concentrations in all adenomas, and low concentrations were found in the surrounding tissues, except for one patient. As compared to levels seen in normal pituitary tissue, the GH concentration in the surrounding tissues was suppressed in five of six cases. TSH and LH concentrations were suppressed in four and three cases, respectively. The PRL concentration was not suppressed in any of the six patients studied. These four hormones were not detected in any adenoma. Plasma GH, TSH, and LH responses to various stimuli which were suppressed preoperatively returned to normal in most of the patients after adenomectomy. Basal plasma cortisol concentrations were normal or subnormal and were suppressed by the administration of 1 mg dexamethasone after adenomectomy, in contrast to the lack of such suppression preoperatively. ACTH and beta-endorphin secretion were stimulated by lysine-8-vasopressin and suppressed by dexamethasone and cyproheptadine in vitro.

The effect of glucose on GH-releasing hormone (GHRH)-mediated GH secretion was examined in six normal young men. In two paired experiments, the six men drank a 75-g glucose solution or an equal volume of water 30 min before receiving, iv, 100 micrograms of the 44-amino acid form of human pancreatic GHRH (hGHRH-44). One week later, the same men underwent an identical experimental protocol in a cross-over trial. Basal plasma GH concentrations before hGHRH-44 administration were not statistically different in the two experiments [glucose experiment, 2.1 +/- 0.1 (+/- SE) ng/ml; water experiment, 2.6 +/- 0.6 ng/ml]. The mean peak plasma GH level occurred 30 min after hGHRH-44 administration in both experiments. However, the mean GH response was significantly diminished when the men received glucose (8.12 +/- 1.12 ng/ml) compared to that when they received only water (23.70 +/- 8.46 ng/ml; P less than 0.01). Thus, hyperglycemia may exert an inhibitory effect on the plasma GH response to hGHRH-44.

Immunoreactive corticotropin-releasing factor (I-CRF) and ACTH (I-ACTH) were examined using RIA, immunoaffinity chromatography, and gel filtration chromatography in human hypothalamus, adrenal (cortex and medulla), lung cancer, and pheochromocytoma. I-CRF and I-ACTH were present in these tissues. Gel filtration of I-ACTH in the adrenal, pheochromocytoma, and lung cancer showed the presence of larger amounts of I-ACTH with large molecular weight forms in contrast to the hypothalamus. Gel filtration of I-CRF in these tissues showed the main peak eluted at the position of synthetic rat CRF. High performance liquid chromatography of this main peak showed two components which eluted in the positions of synthetic rat CRF and oxidized CRF. These elution positions were the same in all tissues and identical with those in the hypothalamus. These results suggest the presence of I-ACTH and I-CRF in these tissues and that CRF outside the brain is identical to hypothalamic CRF.

ACTH, beta-lipotropin (beta-LPH) and beta-endorphin concentrations were determined in pituitary adenomas of the patients with Cushing's disease. Immunoreactive ACTH and beta-endorphin were present in high concentrations and essentially equimolar amounts in pituitary adenomas. beta-LPH conversion to beta-endorphin was activated in pituitaries associated with ACTH/beta-LPH producing adenomas. Immunoreactive ACTH and beta-endorphin concentrations were markedly suppressed in the surrounding tissues.

The distribution and characterization of immunoreactive corticotropin-releasing factor (I-CRF) in human tissues were examined using a rat CRF RIA, immunoaffinity chromatography, gel filtration chromatography, and high performance liquid chromatography. High concentrations of I-CRF were found in the hypothalamus and pituitary stalk. In addition, ICRF was found in the posterior pituitary, thalamus, cerebral cortex, cerebellum, pons, medulla oblongata, spinal cord, and outside the brain and in the adrenal, lung, liver, stomach, duodenum, duodenum, and pancreas. The major component of I-CRF from these tissues eluted in the position of rat CRF on gel filtration chromatography. High performance liquid chromatography of this major component showed two main peaks which eluted in the positions of CRF and oxidized CRF. These elution positions were the same in all tissues. These results indicate the presence of I-CRF outside the brain and suggest that this CRF is identical to hypothalamic CRF.

The relationship of Graves' disease and heredity was studied in 97 clinically and biochemically euthyroid relatives (resin T3 uptake and serum T3, T4, and TSH within normal ranges) who had more than two thyrotoxic relatives within the second degree relationship. TRH tests were preformed in all 97 cases. In 56 of the 97, T3 suppression tests were performed shortly after the TRH test. Results revealed that 29 of the 97 (29.9%) showed an abnormal response to TRH. fourteen of these (14.4%) revealed no response or a hyporesponse, and 15 (15.5%) revealed a hyperresponse to TRH. Four of 56 (7.1%) were T3 nonsuppressible. Seven individuals who showed no response or a hyporesponse to TRH consisted of 2 nonsuppressible and 5 suppressible subjects. In 14 non- or hyporesponsive cases, serum T3 (1.51 +/- 0.05 ng/ml; mean +/- SE) and T4 (9.91 +/- 0.31 micrograms/dl) were significantly higher compared with those of normal responders (1.30 +/- 0.04 ng/ml, 8.57 +/- 0.21 micrograms/dl; P less than 0.001) or hyperresponders (1.16 +/- 0.06 ng/ml, 7.77 +/- 0.63 micrograms/dl; P less than 0.01). There was no correlation between TRH responsiveness and T3 suppressibility. A relatively high occurrence of thyroglobulin and microsomal antibodies was observed, further suggesting a hereditary predisposition. The findings indicate that even in euthyroid relatives with a family history of Graves' disease who have no clinical or biochemical abnormalities of thyroid dysfunction, many have abnormalities in TRH responsiveness, T3 suppressibility, and thyroidal antibodies.

Immunoreactive and receptor-reactive insulin-like growth factor I (IGF-I) was demonstrated in human urine. Thirty percent of the IGF-I immunoreactivity in urine was free, and the remainder was a high mol wt form (approximately 43K). Urinary IGF-I was quantitated by RIA after extraction with octadecylsilyl silica cartridges (Sep-Pak C18 cartridge), a method that measures only free IGF-I. The mean urinary immunoreactive IGF-I levels in normal adults (n = 8) and patients with acromegaly (n = 10) or hypopituitarism (n = 9) were 72 +/- 7 (+/- SEM), 225 +/- 34, and 19 +/- 4 pg/mg creatinine, respectively; these mean values were significantly different from one another. The results indicate that IGF-I is present in human urine and that the quantity in urine is altered in patients with GH excess and deficiency.

Changes in plasma GH levels in response to an intravenous bolus injection of 200 micrograms GHRH-44 or 0.1 U/kg body weight regular insulin were examined in normal men who were pre-treated with 200 micrograms GHRH-44 or 0.1 U/kg body weight regular insulin 120 min in advance. The prior bolus injection of GHRH-44 inhibited the plasma GH response to the subsequent administration of GHRH-44 whereas the plasma GH response to the subsequent injection of insulin was not influenced by the prior administration of GHRH-44. The prior administration of insulin attenuated the plasma GH response to the subsequently given GHRH-44. These results suggest that desensitization of GHRH receptors in somatotrophs and/or somatostatin hypersecretion induced by increase in plasma GH levels following the prior GHRH-44 administration may be involved in the mechanism by which the prior GHRH-44 administration or insulin-induced hypoglycemia suppressed plasma GH responses to the following GHRH-44 administration. Sudden suppression of somatostatin secretion, which causes rebound of GH secretion, may occur in insulin-induced hypoglycemia.

Pituitary-adrenocortical responses to the iv injection of 100 micrograms synthetic ovine corticotropin-releasing hormone (CRH) were studied in 13 patients with anorexia nervosa, and the concentrations of immunoreactive CRH in cerebrospinal fluid were measured in 7 of them. Mean basal levels of plasma ACTH and cortisol were 32 +/- 5 pg/ml (+/- SEM) and 21.1 +/- 1.5 micrograms/dl, respectively. The latter value was significantly higher than that in age-matched normal women (P less than 0.005). The mean increments of plasma ACTH and cortisol in response to CRH injection in those 13 patients were 21 +/- 5 pg/ml and 5.3 +/- 1.7 micrograms/dl, respectively, significantly lower than those in normal women (58 +/- 6 pg/ml and 15.3 +/- 7.7 micrograms/dl, respectively; P less than 0.005). When 4 patients were reexamined after weight gains of between 3 and 22 kg, their responses to the CRH injection increased. The mean concentration of immunoreactive CRH in the cerebrospinal fluid of seven patients was 30.8 +/- 3.9 pg/ml (+/- SEM), which was higher than the value of 18.4 +/- 1.1 pg/ml (P less than 0.005) in control subjects with cervical spondylosis. These findings suggest the possibility that hypersecretion of CRH may occur in patients with anorexia nervosa.

Renin is present in various tissues outside the kidney. In contrast, the levels of angiotensins (ANG), the active products of the renin-angiotensin system, have not been thoroughly evaluated in tissues. In this study, we demonstrated the presence of immunoreactive (ir) ANG I and ANG II in various human tissues by RIA. Of the tissues examined, uterine tissue contained the most ir-ANG II. Since the anti-ANG II antibody used had significant cross-reactivity with ANG III, high performance liquid chromatography was performed to separate ANG II from ANG III. The major portion of the ir-ANG II in the plasma was ANG II. In contrast, the major portion of the ir-ANG II in uterine tissue was determined to be ANG III, a known biologically active peptide. The adrenal gland and testis also contained ANG III. From these results, it can be postulated that ANG III may contribute to the biological activity of ANG in some tissues.

The response of plasma growth hormone to synthetic growth hormone-releasing factor (hpGRF-44) administered intravenously was examined in normal men of various ages ranging from 20 to 75 years. Most of the subjects who were over forty years old had either no or much lower response of plasma growth hormone to hpGRF-44. In contrast plasma growth hormone increased markedly after hpGRF-44 injection in all men in their twenties and thirties. The mean peak level of plasma GH following hpGRF-44 administration was 29.6 +/- 20.4 (SD) ng/ml in men in their twenties, 30.2 +/- 26.5 ng/ml in their thirties, 9.7 +/- 5.2 ng/ml in their forties, 10.9 +/- 5.4 ng/ml in their fifties, 8.4 +/- 4.8 ng/ml in their sixties and 8.1 +/- 7.5 ng/ml in their seventies. These results suggest that somatotroph cells become less sensitive to growth hormone-releasing factor with aging.

The peroxidase-labeled antibody method and the avidin-biotin-complex method with antiserum to purified human kidney renin were used to identify renin in human endocrine tissues. Renin immunoreactivity was found in some large cells of the anterior pituitary, the zona glomerulosa and the zona reticularis of the adrenal, the Leydig cells of the testis, and the follicular epithelial cells of the thyroid and prostate glands. The specificity of the immunohistochemical reaction was confirmed by immunoabsorption tests. The specific localization of immunoreactive renin in each tissue suggests a possible role of renin in the function of these tissues.

Corticotropin-releasing factor (CRF) tests were performed in normal subjects and patients with hypothalamic-pituitary-adrenal disorders. In normal subjects, after iv administration of 500 micrograms synthetic ovine CRF, plasma ACTH rose significantly to approximately 3.6 times the basal level at 30-60 min and cortisol reached a peak of 2.3 times the basal level at 60-90 min, whereas aldosterone peaked at 1.6 times the basal level at 60 min. Injection of 100 micrograms CRF in normal subjects also caused a significant increase in plasma ACTH and cortisol levels but only a slight increase in aldosterone. However, the total hormone released and their peak levels were lower than those elicited by the 500-microgram dosage. In patients with Cushing's disease, although the basal and peak levels of plasma ACTH and cortisol induced by administration of CRF were variable, the ratios of increase for the two hormones elicited by CRF were lower than those in normal subjects, especially for cortisol. In patients with Cushing's syndrome due to an adrenal adenoma, basal levels of ACTH were markedly suppressed and plasma ACTH and cortisol did not rise after CRF. In patients with isolated ACTH deficiency or Sheehan's syndrome the basal level of plasma ACTH was less than 5 pg/ml and no change in plasma ACTH occurred after injection of CRF. In patients with Nelson's syndrome or Addison's disease the basal levels of ACTH were extremely elevated but infusion of CRF increased plasma ACTH to even higher levels.

To determine the pathogenesis of humoral hypercalcemia associated with esophageal carcinoma in a 65-yr-old patient, clonal cell lines (EC-GI) were established from the tumor. The EC-GI cells produced bone-resorbing activity which eluted from a Sephadex G-75 column in a broad peak, with an apparent mol wt of 10,000-50,000. In addition to PTH-like factor(s), the EC-GI cells produced a factor with thymocyte proliferation-stimulating activity which had an apparent mol wt of 15,000-20,000. This interleukin-1 (IL-1)-like factor(s) with acidic pI (4.8 and 5.2) exactly coeluted with the bone-resorbing activity upon DEAE-Sepharose ion exchange chromatography. Both bone-resorbing and thymocyte proliferation-stimulating activities were completely inhibited by anti-IL-1 alpha antiserum, but not by anti-IL-1 beta antiserum. Northern blot hybridization studies revealed that EC-GI cells produced exclusively mRNA for IL-1 alpha. Furthermore, fractions containing IL-1-like activity and PTH-like activity synergistically stimulated bone resorption in vitro, and transplantation of EC-GI cells into nude mice caused hypercalcemia in vivo. These findings suggest that IL-1 alpha and PTH-like factor produced by this squamous cell carcinoma synergistically stimulate bone resorption and are related to humoral hypercalcemia in tumor-bearing nude mice and in the patient.

A case of FSH and LH secreting pituitary adenoma which was not preceded by hypogonadism is reported. The patient, a 50-year-old man, was admitted to the hospital because of left temporal hemianopsia. No clinical evidence of hypogonadism was demonstrated. Endocrine studies of hypogonadism was demonstrated. Endocrine studies revealed markedly elevated plasma FSH of 295 mIU/ml and slightly elevated LH of 35 mIU/ml (2nd IRP-HMG). Plasma FSH and LH did not respond to the administration of LRF, conjugated equine estrogens and testosterone. Plasma testosterone was 691 ng/dl and rose nromally after pregnant mare's serum gonadotropin. Sperm count was 46 X 10(6)/ml. Transfrontal hypophysectomy was followed by a marked decrease of both FSH (to 19mIU/ml) and LH (to 22 mIU/ml). Histologic examination of the tumor revealed 90% chromophobe cells and 10% slightly eosinophilic cells. Two sizes of secretory granules were demonstrated. Tumor cells in tissue culture secreted both FSH and LH.

An ovarian perifusion technique was used to determine if there is a direct suppressive effect of PRL on human gonadal steroid secretion. Ovarian tissue from nine patients was examined. Ovine PRL (0.1-10 IU/ml) directly suppressed progesterone and 17 beta-estradiol secretion by human ovaries. hCG (1-10 IU/ml) stimulated both progesterone and 17 beta-estradiol secretion. Simultaneous administration of PRL (5-10 IU/ml) suppressed the stimulatory effect of hCG. The ovarian tissue obtained from a hyperprolactinemic patient did not respond to hCG. These results indicate that PRL inhibits both basal and gonadotropin-stimulated ovarian steroid secretion by human ovaries and that this may be one cause of the hypogonadism associated with hyperprolactinemia.

Synthetic growth hormone-releasing factor (hpGRF-44) (100 micrograms) was administered intravenously to ten acromegalic patients. The time when the peak of plasma GH occurred as well as the magnitude of the response were highly variable among these ten patients. From the GH response patterns the ten acromegalic patients were tentatively classified into three groups: (1) those highly GRF-dependent whose GH level increased to four times basal, (2) those moderately GRF-dependent whose GH level rose to less than two times basal and (3) those GRF-resistant whose GH level did not change. These data suggest that there may be differences in the GRF-receptor system in pituitary adenomas causing acromegaly.

Up to the present, 4 methods applicable to study of the electrical properties of skin have been proposed for the diagnosis of thyroid diseases: constant-current resistance, capacitance with audio-frequency current, impedance angle, and impedance. However, accurate correlation of these parameters with the histologic structure of the skin has not been possible. In this study, the initial capacity of the skin to resist a constant current was measured by a new electrical method in 75 untreated subjects with suspected thyroid disease. It was found that: 1) the correlation coefficient between the initial capacity and the basal metabolic rate was 0.90 in 19 males and 0.74 in 56 females, and between the initial capacity and the 24-hour thyroidal I131 uptake was 0.88 in 13 males and 0.61 in 33 females; 2) the initial capacity was normal or higher in 15 hyperthyroid patients and the lower than normal in 5 hypothyroid patients, whereas in 17 euthyroid subjects with nontoxic goiter and in 17 subjects with nonthyroid ...

Thyroidal absolute iodine uptake (AIU) and the degradation of thyroxine were compared in euthyroid Japanese subjects (9 males and 6 females) whose diet customarily included moderate to large quantities of foods rich in iodine. AIU was measured a) from thyroidal clearance of 131I and serum inorganic 127I, and b) from thyroidaly 131I uptake and specific activity of urinary iodine. Values for both methods agreed well and increased as serum inorganic 127I or urinary 127I increased, while the degradation of thyroxine measured in the same subjects did not differ greatly with differing serum inorganic 127I or urinary 127I. Invariably, values for AIU were higher than those for the degradation of thyroxine. Protein-bound 131I in normal thyroid tissue collected at surgery (5 subjects) was more than 85% of total thyroidal 131I when 131I was injected 2 hr before thyroidectomy. These results suggest that thyroid glands of Japanese subjects on a diet rich in iodine organify more 127I than they secrete as thyro...

LATS is inactivated when incubated with human thyroid particulate fraction (HTP). This inactivation is presumed to be due to binding of LATS to the fraction. In the present investigation, we sought to determine whether binding to thyroid particulate fraction is related to the thyroid-stimulating activity of LATS, by comparing LATS inactivation by comparable quantities of human and murine thyroid particulate fraction (MTP) with that of chicks (CTP) whose thyroid glands have been shown not to be stimulated by LATS. HTP inactivated LATS markedly and regularly, while both MTP and CTP did so only slightly and erratically. On the other hand, intracellular colloid droplets were induced in vitro by LATS to a significant extent in murine as well as human thyroid tissue, while not in chick thyroid tissue. These findings suggest that thyroid-Stimulation by LATS is not necessarily accompanied by its inactivation and that inactivation of LATS in vitro is not due to the same binding which precedes thyroid activation.