Abnormal Responsiveness to Dexamethasone-Suppressed CRH Test in Patients With Bilateral Adrenal Incidentalomas.

CONTEXT: The bilateral formation of nodules indicates that the pathogenesis of bilateral adrenal incidentalomas (AI) may differ from that of unilateral AI. A possible role of hypothalamo-pituitary-adrenal (HPA) axis dysregulation in their formation has not been investigated. OBJECTIVE: The objective of the study was to evaluate the presence of altered feedback regulation of HPA axis in patients with bilateral AI. DESIGN: The dexamethasone (DEX) suppression-CRH test was used to assess ACTH and cortisol responses in controls and patients with unilateral and bilateral AI. SETTING: The study was conducted at endocrine departments of two tertiary centers. PATIENTS: We studied 24 controls and 39 patients with unilateral and 46 with bilateral AI. INTERVENTIONS: All subjects underwent standard low-dose dexamethasone suppression followed by iv bolus administration of human CRH (100 µg). RESULTS: Bilateral AI had higher levels of ACTH and cortisol after the DEX-CRH challenge compared with both controls (P < .01 for ACTH and P < .001 for cortisol) and unilateral AI (P < .01 for ACTH and cortisol). A positive response, defined as peak ACTH greater than 10 pg/mL at 15 and/or 30 minutes followed by a significant rise in cortisol levels, was noted in 41.3% of bilateral vs 2.6% in unilateral AI (P < .001). Bilateral responders did not differ from nonresponders in demographic or hormonal characteristics, but they had larger total adrenal size compared with nonresponders. CONCLUSIONS: A significant proportion of patients with bilateral AI demonstrate positive responses to the DEX-CRH test compared with unilateral AI, providing ground for potential involvement of HPA axis dysregulation in the pathogenesis, in at least a subgroup, of bilateral AI patients.

Incidence of pituitary incidentalomas in patients with adrenal adenomas.

With the advent of modern imaging modalities, endocrine incidentalomas are increasingly being discovered. We aimed to investigate the presence of pituitary incidentalomas (PI) in patients with adrenal incidentalomas (AI), and identify potential metabolic correlates in this cohort. 26 patients (18 females) with AI discovered on abdominal computerized tomography were studied. All patients underwent pituitary magnetic resonance imaging (MRI) and endocrine investigations to evaluate functional adrenal pathology, anterior pituitary hormonal status, insulin-resistance indices and presence of metabolic syndrome. Pituitary MRI revealed a microadenoma and a 4×5 mm cyst in 1 patient respectively, and an empty sella in 4 (2 partial) patients. Overall, 6/26 (23%) patients with an AI had evidence of pituitary imaging pathology but only 8% had a PI; none had any evidence of abnormalities in pituitary function. Subclinical hypercortisolism was the only hyperfunctional status detected in 4 patients with AI but was unrelated to the pituitary findings. No abnormality of insulin secretion and action was found between patients with or without pituitary pathology. In the present study 23% of patients with AI had some alteration in pituitary morphology, and 2 a PI without accompanying pituitary hormonal deficit or metabolic derangement. Further studies are required to address this issue and identify a potential pathogenetic mechanism.

Response to the article: "primary aldosteronism: are we missing the wood for the trees?".

This letter is a short response to Dr Funder's recent commentary on primary aldosteronism under the title "Primary aldosteronism: are we missing the wood for the trees?". We briefly discuss recent data from our department on autonomous aldosterone secretion (AAS) and the efficacy of mineralocorticoid receptor antagonists in a group of patients with AAS, that would otherwise remain undiagnosed.

Azathioprine as an alternative treatment in primary hypophysitis.

Primary hypophysitis (PH) is an unusual disorder characterized by inflammatory infiltration of the pituitary gland with various degree of pituitary dysfunction. Glucocorticoids are the treatment of choice in the majority of patients. Still, in patients with poor response in glucocorticoids or when their administration is accompanied with serious side effects, the use of alternative agents should be considered; up to now, data on other therapeutic approaches remains scant mainly due to the rarity of the disease. Among them, the immunosuppressant azathioprine could represent an effective and safe alternative. In this article, we present our clinical experience of two cases with PH successfully treated with azathioprine following serious side effects after initial treatment with glucocorticoids and provide a brief review of the existing literature.

Cardiovascular risk factors in adult patients with multisystem Langerhans-cell histiocytosis: evidence of glucose metabolism abnormalities.

BACKGROUND: Langerhans-cell histiocytosis (LCH) is a rare disease with features of chronic inflammation and it may also induce hypopituitarism, conditions associated with an increased risk of cardiovascular diseases. AIM: Cardiovascular and metabolic risk profile investigation in multisystem LCH patients with and without anterior pituitary deficiency. DESIGN: Prospective, observational study. METHODS: Fourteen adult patients with LCH, 7 with and 7 without anterior pituitary deficiency, and 42 controls matched for age, body mass index (BMI) and smoking. Cardiovascular risk factors were estimated in all subjects: glucose and lipid profile, mathematical indices of insulin resistance (IR), blood pressure, structural arterial and functional endothelial properties (intima-media thickness, brachial artery flow-mediated dilatation). Cardiovascular risk factors were estimated in the three groups studied; the effect of disease activity and/or treatment was also determined in patients with LCH. RESULTS: Ten patients had diabetes insipidus, and 7 anterior pituitary hormone deficiencies: 8 patients had active disease and 11 had received systemic treatment. No difference was observed between the study groups in vascular parameters, in lipid profile or in blood pressure. However, the insulin resistance index GIR was decreased in patients with LCH without anterior pituitary deficiency compared to controls (P = 0.033). Three patients had impaired glucose tolerance and one diabetes mellitus type 2. These patients were older and had active disease; there was no association with hypopituitarism and/or previous treatment. CONCLUSION: Adults patients with LCH have abnormalities of glucose metabolism that tend to occur in patients with active disease, and may be a consequence of the pro-inflammatory state.

Evolving radiological features of hypothalamo-pituitary lesions in adult patients with Langerhans cell histiocytosis (LCH).

Langerhans cell histiocytosis (LCH) is a rare, systemic disease caused by monoclonal expansion of dendritic cells that shows a particular predilection for the hypothalamic-pituitary system (HPS). We studied the function (anterior and posterior pituitary hormonal secretion) and morphology using magnetic resonance imaging (MRI) of the HPS in 17 adult patients (seven males, median age 35 years, range 18-59 years) with multisystem LCH. We also evaluated the evolution of structural HPS abnormalities in relation to pituitary function and response to treatment in 12 of these patients during a median follow-up period of 3.75 years (range 1.5-10 years). Of the 17 patients, 14 (82%) had abnormal HPS imaging, and 12 (70%) had more than one area involved. Lack of the bright spot of the posterior pituitary lobe was typically found in all patients with the diagnosis of diabetes insipidus (DI). Eight patients (47%) had infundibular enlargement, six (35%) pituitary infiltration, four (24%) partially or completely empty sella, three (18%) hypothalamic involvement, and two (12%) infundibular atrophy. DI was found in 16 patients (94%) and anterior pituitary hormonal deficiency (APHD) in 10 patients (59%); two patients had single (12%) and 8 (47%) multiple APHD. During the follow-up period there was improvement of the initially demonstrated HPS pathology in seven (47%) patients, and five (33%) of them had received at least one form of treatment. APHD and DI persisted in all patients except in one in whom established gonadotrophin deficiency recovered. In summary, DI and APHD are very common in patients with multisystem LCH and are almost always associated with abnormal HPS imaging.

Treatment with oral biphosphonates can increase the sensitivity of sestamibi radionuclide imaging in patients with primary hyperparathyroidism.

The sensitivity of 99mTc-sestamibi scan in detecting parathyroid disease in primary hyperparathyroidism (PHP) is almost 90%, and therefore facilitates successful parathyroidectomy. To enhance the diagnostic accuracy of the procedure, we repeated imaging with 99mTc-sestamibi in 15 patients with PHP and an initially negative (11 patients) or weakly positive (four patients) 99mTc-sestamibi scan after the administration of 10 mg of oral alendronate for 2 months. Serum calcium, phosphate and parathormone (PTH) measurements were obtained at presentation and after 1 and 2 months' treatment with alendronate. Eight patients with an initially negative 99mTc-sestamibi scan demonstrated at least one area of uptake in the repeated scan. Six of these patients underwent surgery and obtained a biochemical cure; a single adenoma was found in four and hyperplasia in the remaining two. In all four patients with an initially weakly positive 99mTc-sestamibi scan, the repeated scan demonstrated enhanced uptake and also revealed further areas of uptake. Two of these patients underwent surgery with a biochemical cure; an adenoma was found in one and hyperplasia in another. Compared with baseline there was a significant increase in PTH but not in calcium or phosphate levels during treatment with alendronate. We suggest that, in patients with PHP and a negative or weakly positive initial 99mTc-sestamibi scan, administration of oral alendronate may be associated with a positive repeated 99mTc-sestamibi scan and can thus enhance the sensitivity of the procedure.

Ectopic bioactive luteinizing hormone secretion by a pancreatic endocrine tumor, manifested as luteinized granulosa-thecal cell tumor of the ovaries.

Endocrine pancreatic tumors are rare neoplasms consisting of multipotent cells capable of secreting various bioactive substances causing characteristic clinical syndromes. Ovarian stromal hyperthecosis is characterized by varying degrees of luteinized stromal cell proliferation after sustained LH and/or human chorionic gonadotropin stimulation, clinically manifested by symptoms/signs of virilization resembling the polycystic ovary syndrome (PCOS). We report a case of ectopic bioactive LH production from a pancreatic endocrine tumor in a 33-yr-old woman with rapidly developing symptoms/signs of hyperandrogenism and markedly elevated serum androgen and LH levels leading to hyperthecosis and bilateral luteinized granulosa-thecal cell tumors of the ovaries. Although the patient was initially thought to have either severe PCOS or an LH-secreting pituitary tumor, an LH-producing pancreatic endocrine tumor bearing somatostatin receptors was demonstrated on scintigraphy with [111In]octreotide and abdominal imaging. Symptoms and signs of hyperandrogenism resolved after the resection of the tumor. Immunohistochemistry, in situ hybridization, and electron microscopy studies confirmed LH synthesis by the tumor cell. Although extremely rare, ectopic LH production from nonpituitary endocrine tumors should be considered in the differential diagnosis of hyperandrogenism, particularly when associated with highly elevated serum LH levels.

Composite somatotroph--ACTH-immunoreactive pituitary adenoma with transformation of hyperplasia to adenoma.

The majority of pituitary adenomas are solitary and monohormonal, producing only one hormone. Double or multiple adenomas are rare. Plurihormonal adenomas may be monomorphous consisting of one cell type producing more than one hormones or plurimorphous composed of two or more distinct cell populations each producing different hormones. Primary pituitary hyperplasia is uncommon and transformation to adenoma has rarely been documented. We describe a unique case of somatotroph adenoma combined with ACTH-immunoreactive cell hyperplasia and focal transformation to adenoma. The 53-yr-old man was presented with a 2-yr history of headaches, enlargement of the hands and feet and coarsening of facial features. His blood GH was 17.5 ng/ml and he had absence of GH suppressional oral glucose tolerance testing. MRI demonstrated a mass with maximum diameter of 1.5 cm, on the left side of the pituitary, without invasion of surrounding tissues. Transsphenoidal surgery was performed. Morphology disclosed a mostly chromophobic tumor, immunoreactive for GH with ultrastructural characteristics of sparsely granulated somatotroph adenoma. The adenoma cell population was focally admixed with hyperplastic PAS positive and ACTH immunoreactive cells showing the electron microscopic features characteristic of corticotrophs. In these areas the acini were enlarged with distorted architecture of the reticulin pattern. Dissolution of the reticulin fiber network and transformation of hyperplastic ACTH-immunoreactive cells to adenoma was evident in small areas. The hyperplastic and adenomatous ACTH-immunoreactive cells were admixed with somatotroph adenoma cells. Due to lack of biochemically obvious cortisol hypersecretion, this ACTH-immunoreactive adenoma was classified as silent "corticotroph" subtype 1. This is an unusual case of composite pituitary adenoma consisting of somatotroph cells and hyperplastic ACTH-immunoreactive cells transforming to a frank adenoma.

Structure-function correlations of growth hormone or/and prolactin-producing pituitary adenomas: an in vitro study with the reverse hemolytic plaque assay.

The purpose of this study was to detect in vitro growth hormone (GH) and prolactin (PRL) secretion from adenomas clinically associated with GH or PRL hypersecretion. The reverse hemolytic plaque assay (RHPA) was applied in order to reveal possible differences among various morphologic adenoma types, and to examine the inhibitory effects of octreotide on GH release as well. The 20 surgically resected pituitary adenomas studied included 15 from acromegalic patients and 5 from patients with hyperprolactinemia. All adenomas were diagnosed by histology, immunocytochemistry and electron microscopy. Among tumors associated with acromegaly, 5 were densely granulated (DG), 5 were sparsely granulated (SG) somatotroph (SM) adenomas, 2 were mammosomatotroph (MSM) and 3 mixed somatotroph-lactotroph cell (mixed SM-LT) adenomas; tumors causing hyperprolactinemia included 4 lactotroph (LT) adenomas and 1 mixed SM-LT adenoma. GH release assessed by the RHPA corresponded to in vivo hormone secretion and to tissue immunoreactivity. Statistical analysis showed significant differences among all morphologic types of SM adenomas, exclusive of SG-SM adenomas compared to mixed SM-LT adenomas. The mean plaque size in DG-SM and MSM adenomas was significantly greater than that of SG-SM and mixed SM-LT adenomas, indicating higher GH secretion by the former two types during the same incubation time. PRL secretion was documented in 2 mixed SM-LT adenomas. Plaques for PRL, but not for GH were formed in all LT adenomas. In all SM and LT adenomas, cells producing large plaques represented a minority of the plaque-forming cell population, however, they accounted for the largest part of the total plaque area, thus the largest part of hormone secretion. Octreotide effects on GH release were studied in 6 adenomas by the RHPA. Octreotide treatment induced a rapid and significant reduction in GH secretion by SM cells in vitro, with a selective effect on high-secreting cells.

Triple pituitary adenoma in Cushing's disease: case report.

A case of a triple pituitary adenoma identified in a surgically removed pituitary gland from a 52-year-old woman operated on for Cushing's disease is presented. The histology revealed 3 distinctly separate microadenomas, 1 corticotroph and 2 immunoreactive for prolactin (PRL). The latter were apparently silent, since the serum PRL levels were within normal range. The problems associated with the inability to identify multiple adenomas pre-operatively and the possible failure of selective transsphenoidal adenomectomy in case of multiple adenomas are emphasised.

Apoptosis in human pituitary adenomas: a morphologic and in situ end-labeling study.

Apoptosis seems to be an important process in normal tissues and in neoplastic lesions. Although electron microscopic features of apoptosis are characteristic, it is difficult to detect apoptotic cells with accuracy by light microscopy. Labeling of intranucleosomal DNA fragmentation can provide information on the apoptotic status of tumors. We studied apoptosis by the in situ end-labeling technique in 85 pituitary adenomas (63 functioning, 22 nonfunctioning). The functioning tumors included 19 somatotroph, 17 lactotroph, 9 mixed growth hormone/prolactin-producing, 2 thyrotroph, and 16 corticotroph adenomas. A few scattered cells displaying characteristic apoptotic changes were observed by histologic examination and electron microscopy. We estimated the apoptotic labeling index (ALI) of the adenomas by quantitating the percentages of positive nuclei. Overall, functioning adenomas showed a significantly higher ALI (5.64%) than did nonfunctioning tumors (1.84%). The ALI was higher in thyrotroph adenomas (10.26%) and lower in corticotroph (5.94%), somatotroph (5.51%), lactotroph (5.25%), and mixed growth hormone/prolactin-producing adenomas (5.11%). In conclusion, in situ end-labeling showed that apoptosis mostly occurs in functioning pituitary adenomas. These data suggest that assessment of apoptosis can be used to evaluate drug effects and to define which adenoma subtypes are more susceptible to drug therapy.

The effect of sequential administration of octreotide alone and octreotide/growth hormone simultaneously on buserelin stimulated ovarian steroid secretion in women with polycystic ovary syndrome.

OBJECTIVE: GH increases oestradiol secretion and promotes oocyte development in women with polycystic ovary syndrome (PCOS). However, there are no data on ovarian androgen production after GH treatment. We have therefore assessed the effect of sequential treatment with a long-acting somatostatin analogue (octreotide) alone and octreotide/GH simultaneously on ovarian steroid levels in PCOS and non-PCOS normal women. PATIENTS: Twenty-six PCOS and 12 non-PCOS women, aged 18-35 years, were studied. Ten of the PCOS and six of the non-PCOS women received sequential treatment with octreotide alone and followed by octreotide + GH together, while another eight PCOS and six non-PCOS women received saline instead of octreotide-octreotide + GH. The remaining eight PCOS women received GH alone. DESIGN: The octreotide-octreotide + GH and saline studies lasted 12 days, the GH alone 7 days. Octreotide (100 micrograms, s.c., t.d.s.) was given from the 2nd to the 10th and octreotide + GH (4 IU, s.c. at 2300h) from the 7th to the 10th day of the study. The GH alone treatment was given from the 2nd to the 5th day. On the 1st day, two tests were performed: (1) an oral glucose tolerance test (OGTT, 75 g, orally) at 0830h and (2) a buserelin (long-acting GnRH agonist) test (100 micrograms, s.c.) at the end of the OGTT. Both tests were repeated on the 6th and 11th days in the octreotide-octreotide + GH or on the 6th day only in the GH alone study. MEASUREMENTS: Blood glucose, insulin (IRI), C-peptide and IGF-I (at time 0 only) were measured before glucose administration and at 30-minute intervals for 3 hours and LH, FSH, delta 4-androstenedione (delta 4A), testosterone (TT), free testosterone (FT) and oestradiol (E2) before buserelin and at 1,2,6,10,14 and 18 hours. RESULTS: Octreotide alone significantly reduced the basal IGF-I stimulated LH and both basal and stimulated IRI, delta 4A, TT, FT and E2 levels in all PCOS women tested. Both octreotide + GH and GH alone increased significantly the basal IGF-I and both basal and stimulated IRI and E2 levels in all PCOS women, while the basal and stimulated LH, delta 4A, TT and FT levels were completely unaffected. In contrast, octreotide-octreotide + GH treatment did not modify either basal or stimulated gonadotrophin or ovarian steroid levels in non-PCOS women. No changes in either basal or stimulated hormone levels were observed in those PCOS women who received saline. Although both basal and stimulated levels of all ovarian androgens were significantly reduced by octreotide-octreotide + GH treatment in PCOS women, they still remained significantly higher than in the non-PCOS women. CONCLUSIONS: The data show that (1) octreotide is a potent inhibitor of ovarian steroid secretion, (2) GH increases oestradiol secretion, possibly by stimulating ovarian aromatase activity, and (3) the combined treatment with octreotide and GH significantly improves ovarlan function in women with PCOS and may thus have important clinical implications for the management of infertile women with this syndrome.

Ovarian function in women with non-insulin dependent diabetes mellitus.

OBJECTIVE: Although insulin has been shown to stimulate ovarian steroidogenesis and hyperinsulinaemia has been implicated in the raised androgen levels found in diseases associated with significant insulin resistance, ovarian function has not been studied so far in women with NIDDM. We have assessed ovarian function in women with NIDDM at the early (hyperinsulinaemic) and late (relative insulinopaenic) stages of evolution of the disease after strong stimulation with buserelin, a long-acting GnRH analogue. Significant differences in ovarian function would be expected, depending on the stage of evolution of NIDDM. DESIGN: Following an overnight fast, a standard OGTT (75 g, orally) was performed (0830 h) in all diabetic and control women. Blood samples were obtained for blood glucose, insulin and C-peptide measurements before and at 30-minute intervals for 2 hours. On the termination of the OGTT, a buserelin test (100 micrograms, s.c.) was performed (1030 h) and blood samples were obtained for FSH, LH, delta 4-androstenedione, total testosterone, free testosterone and oestradiol measurements before and then at 4-hour intervals for 20 hours. SUBJECTS: Thirty-one women with NIDDM (13 hyperinsulinaemic and 18 with relative insulinopaenia), 12 obese and 11 normally menstruating non-obese, non-diabetic women, aged 29-39 years, were studied. RESULTS: The integrated response (AUC) of oestradiol to buserelin was found to be normal in hyperinsulinaemic NIDDM and obese non-diabetic women in the face of an increased free testosterone response, while in relatively insulinopaenic NIDDM women the oestradiol response was significantly reduced in the face of a normal free testosterone response. CONCLUSIONS: The results suggest that in women with NIDDM the ovaries have a reduced ability to convert androgen to oestrogen, probably due to a reduction of ovarian aromatase activity. As oestrogens protect against atherogenesis, it is speculated that the relative inability of the ovaries to produce oestradiol in NIDDM women with relative insulinopaenia might be involved in the development of the macroangiopathy, which often complicates this disease.

Dysfunction of the growth hormone/insulin-like growth factor-I axis in women with polycystic ovarian syndrome.

OBJECTIVE: Although a defect in GH regulation has been suggested in women with polycystic ovarian syndrome (PCOS), the data are limited and mechanism obscure. We have assessed the function of the GH/IGF-I axis in women with PCOS by measuring basal IGF-I levels and the ability of the pituitary to secrete GH following dopamine and GHRH. DESIGN: For each woman the complete study lasted 3 days. On the 1st and 2nd days, saline (0.9%, 5 ml/h for 3 h) and dopamine (4 micrograms/kg/min for 3 h) infusion tests were performed, respectively, in all PCOS and control women. Blood samples for GH measurement were obtained before and at 20-minute intervals for 3 hours. On the 3rd day a GHRH test (100 micrograms, i.v. bolus) was performed in 9 of the women with PCOS and in 9 controls. Blood samples for GH measurements were obtained before and at 20-minute intervals for 3 hours. Basal IGF-I levels were measured in the basal blood samples from the saline infusion test in all patients studied. SUBJECTS: Thirteen women with PCOS and 11 normally menstruating women (control group), aged 18-35 years, were studied. All women with PCOS had hirsutism and oligomenorrhoea since menarche, elevated serum values of at least one ovarian androgen and the typical ultrasound appearance of PCOS. RESULTS: Growth hormone releasing hormone (GHRH) induced a significant increase in GH secretion in both control and PCOS groups. However, the GH response to GHRH was found to be significantly lower in women with PCOS. The 3-hour infusion of dopamine induced a significant increase in GH levels only in the control group, while it failed to stimulate GH release in the women with PCOS. Although both dopamine and GHRH failed to induce a normal GH response in women with PCOS, their IGF-I levels did not differ significantly from those observed in control women. CONCLUSIONS: The diminished GH responses to both GHRH and dopamine in women with PCOS, in the presence of normal circulating IGF-I levels, suggests a dysregulation in GH secretion. Although the data are suggestive of a hypothalamic defect, further studies are required to clarify the underlying mechanism and the role, if any, of GH in the pathogenesis of polycyctic ovarian syndrome.

The interaction of growth hormone releasing hormone with other hypothalamic hormones on the release of anterior pituitary hormones.

To determine whether the 29 amino-acid fragment of growth hormone releasing hormone (GHRH) can be combined with other hypothalamic releasing hormones in a single test of anterior pituitary reserve, the responses of anterior pituitary hormones to combinations of an i.v. bolus of GHRH(1-29)NH2 or saline with an i.v. bolus of either LH releasing hormone (LHRH) plus TRH, ovine CRH(oCRH) or saline were studied. Each infusion of GHRH(1-29)NH2 resulted in a rapid increment of the plasma GH value. Infusion of GHRH(1-29)NH2 also caused a small and transient rise in plasma PRL, but no change in the integrated PRL response. The combination of GHRH(1-29)NH2 with LHRH plus TRH caused a larger increment of peak and integrated plasma TSH levels than LHRH plus TRH alone. GHRH(1-29)NH2 did not affect the release of other anterior pituitary hormones after infusion with oCRH or LHRH plus TRH. Because of the finding of potentiation of the TSH-releasing activity of LHRH plus TRH by GHRH(1-29)NH2, the study was extended to the investigation of TSH release after infusion of TRH in combination with either GHRH(1-29)NH2 or GHRH(1-40). In this study the combination of TRH with both GHRH preparations also caused a larger increment of the peak and integrated plasma TSH levels than TRH alone. It is concluded that GHRH(1-29)NH2 possesses moderate PRL-releasing activity apart from GH-releasing activity. In addition, GHRH potentiates the TSH-releasing activity of TRH.(ABSTRACT TRUNCATED AT 250 WORDS)

A sensitive and specific immunoradiometric assay (IRMA) for human thyroid stimulating hormone.

A liquid phase "two-site" immunoradiometric assay (IRMA) specific for human thyroid stimulating hormone (hTSH) is described. The assay is based on the simultaneous addition of affinity purified sheep anti hTSH IgG-I 125 and rabbit anti hTSH antiserum to standards and unknowns followed by 4h incubation at room temperature. The separation of free labelled sheep IgG-I125 from that bound to hTSH is achieved by the addition of sheep anti-rabbit IgG Fc fragment antiserum. The radiolabelled sheep anti-hTSH IgG-I 125 was pretreated with solid phase urinary postmenopausal gonadotropins to remove cross reaction with FSH and LH. The assay is specific for hTSH and no cross reaction with the other anterior pituitary glycoproteins or protein hormones has been found. In addition it is characterized by a wide operating range, rapid equilibration of reactants and high sensitivity (0.02 microU/ml). The precision of dose estimates was less than 10% between 0.25-2.5 microU/ml and less than 2.5% over the range 2.5-60 microU/ml.

The sulpiride test in panhypopituitarism.

The results obtained with a new test of prolactin (PRL) release in six panhypopituitary patients as compared to fourteen normal subjects (eight females and six males) are presented. The test consists of the i.m. administration of 100 mg of sulpiride and the measurement of plasma PRL by a double antibody radioimmunoassay techniques at--15, 0, 15, 30, 45, 60, 75, 90, 105 and 120 min. Mean baseline PRL values were not significantly different in the three groups. After sulpiride a 800-4200% increment of prolactin over control values was noted in the females and 1200-3500% increment in the males. The peak values were obtained at 15 or 30 min (6030+/-670 mu/l +/-SEM in the females and 5550+/-870 mu/l in the males). The mean values were not significantly different in the two sexes until the sixtieth minute but were significantly higher (P less than 0.05) in the female thereafter. In the hypopituitary patients a complete failure of response was noted. These results show that the sulpiride test possesses a considerable potential as a screening procedure in the diagnosis of pituitary insufficiency.