Clinical review of 20 cases of Addison's disease in Korea--including previously reported cases and 6 new cases at the National Medical Center

Addison’s disease is a rare disorder resulting from a chronic deficiency of adrenol cortical hormone. The clinical manifestations and data of 20 patients with Addison’s disease were reviewed. They include 14 previously reported cases, total cases in korea upto 1987, and 6 new cases at National Medical Center. 13 patients were male and 7 female. The mean age was 39 years and ranged from 16 to 61 years. Common symptoms included mucocutaneous pigmentation (95 %), general weakness (90%), nasuea and/or vomiting (80%), and weight loss (60%). Initial mean blood pressure was 96±21/63±14 mmHg and adrenal crises were found in 5 cases (25%). Laboratory data indicated hyponatremia and hyperkalemia, resulting in a decreased Na/K ratio. Serum basal cortisol and ACTH levels were 2.86±1.93 ug/dl and 482.5/269.3 pg/ml, respectively. Extra-adrenal tuberculosis was present in 14 cases (70%) as a very high incidence. These 14 cases (70%) were presumed to be due to adrenal tuberculosis, although only two cases were confirmed as such by histopathology. The other cases were likely to be non-tuberculous.

Thus, tuberculosis may be-considered as a predominant cause of Addision’s disease in Korea. Other features were not unusual. But further detailed and extensive studies are necessary including more pathologically confirmed cases.

Effects of fludrocortisone withdrawal on plasma angiotensin II, ACTH, vasopressin, and potassium in patients with Addison's disease

We attempted to answer to the question whether excessive rises in endogenous plasma angiotensin II (AII) stimulate ACTH secretion by measuring PRA, AII, AVP, ACTH, and cortisol in 8 patients with Addison's disease before and after withdrawal of fludrocortisone substitution. Blood was drawn at 14.30 h, exactly 6 1/2 h after the morning dose of hydrocortisone had been taken. PRA and AII were initially higher than normal in 4 patients. After withdrawal of fludrocortisone for 1 or 2 weeks, PRA and AII rose markedly in 4 patients (up to 260 ng/l) without concomitant changes in plasma ACTH levels (r = -0.081, AII vs ACTH). Changes in plasma cortisol could not have obscured a stimulatory effect of AII on ACTH by variable feedback inhibition of ACTH release. The increase in plasma AII levels in the 4 patients was larger than that observed in a previous study in normal subjects after rigorous dietary sodium restriction. In all patients, hyperkalaemia developed after fludrocortisone withdrawal, independent of changes in PRA and AII. Rises in PRA, AII, and plasma potassium were partially reversed by increased sodium intake and further suppressed by resumption of fludrocortisone therapy. Plasma AVP remained in the normal range after fludrocortisone withdrawal, but was slightly elevated after increasing salt intake without fludrocortisone administration.

CONCLUSIONS

Rises of endogenous plasma AII to levels tenfold higher than normal do not stimulate ACTH release. AII is probably not a physiological modulator of ACTH secretion. Mineralocorticoid substitution in Addison's disease should be monitored by plasma potassium measurement. Hyperkalaemia may coexist with normal PRA.(ABSTRACT TRUNCATED AT 250 WORDS)

Direct measurement of human plasma corticotropin-releasing hormone by "two-site" immunoradiometric assay

A "two-site" immunoradiometric assay (IRMA) which allows the direct estimation of human CRH (hCRH) in plasma is described. Using this IRMA, basal levels of CRH in normal subjects ranged from 2-28 pg/mL [mean, 15 +/- 7 (+/- SD) pg/mL; n = 58]. Values in men and women were similar. Plasma CRH values within this range were also found in patients with Cushing's syndrome, Addison's disease, and Nelson's syndrome, with no correlation between plasma CRH and ACTH levels in these patients. Elevated plasma CRH levels were found in pregnant women near term [1462 +/- 752 (+/- SD) pg/mL; n = 55], and the dilution curve of this CRH-like immunoreactivity paralleled the IRMA standard curve. After its immunoadsorption from maternal plasma, this CRH-like material eluted on reverse phase high performance liquid chromatography with a retention time identical to that of synthetic CRH and had equipotent bioactivity with the synthetic peptide in the perfused anterior pituitary cell bioassay. Circulating CRH was not detected in Wistar rats, even after adrenalectomy and subsequent ether stress. Synthetic hCRH was degraded by fresh human plasma relatively slowly; 65% of added CRH remained after 1 h of incubation at 37 C. Degradation was inhibited by heat treatment (54 C; 1 h), cold treatment (4 C; 4 h), or freezing and thawing. Loss of synthetic rat CRH occurred more rapidly when fresh rat plasma was used; only 20% of added CRH remained under the same conditions. The inability to measure CRH in peripheral rat plasma may be due to the presence of active CRH-degrading enzymes which fragment the CRH molecule into forms not recognized by the CRH IRMA.

Measurement of circulating corticotrophin-releasing factor in man

A radioimmunoassay was developed to measure corticotrophin-releasing factor (CRF-41) extracted from human plasma using Vycor glass. Assay sensitivity was 20 ng/l and intra- and interassay coefficients of variation were 10.2 and 11.4% respectively. The normal range of plasma CRF-41 was less than 20-110 ng/l (n = 46). Plasma concentrations of CRF-41 in patients with Cushing's disease. Nelson's syndrome and Addison's disease were within the normal range. No correlation was found between CRF-41 and ACTH in these syndromes. Two patients with the ectopic ACTH syndrome had increased plasma concentrations of CRF-41. In normal subjects no changes in plasma CRF-41 occurred after insulin-induced hypoglycaemia, treatment with dexamethasone or feeding, and changes in the concentrations of CRF-41 did not reflect circadian changes in plasma concentrations of cortisol. Concentrations of immunoreactive CRF in plasma of women in the third trimester of pregnancy were increased (550-9300 ng/l) and gel filtration chromatography showed that this comprised CRF-41 and a higher molecular weight form. Reversed-phase high-performance liquid chromatography also revealed multiple peaks of immunoreactive CRF in extracts of plasma and placenta.

Bone mineral density in Addison's disease: evidence for an effect of adrenal androgens on bone mass

It is unknown whether replacement doses of cortisone acetate and the absence of the small amounts of androgens secreted by the adrenal cortex may cause osteoporosis. This was studied in 35 patients (12 men and 23 women) suffering from primary adrenocortical failure and taking cortisone acetate 25-37.5 mg and fludrocortisone 50-100 micrograms daily. Bone mineral density was measured by single photon absorptiometry at the midshaft of the radius, representing cortical bone, and at the distal part of the radius, a site with a significant trabecular component. The bone mineral density was normal in premenopausal female patients as well as in male patients, showing that replacement doses of cortisone acetate do not affect bone mass. By contrast, in postmenopausal patients there was a dramatic bone loss in addition to the physiological postmenopausal decrease in bone mass. This loss, combined with the low plasma concentrations of androstenedione, dehydroepiandrosterone, and testosterone (and low concentrations of oestrone of adrenal origin), indicates that adrenal androgens may be essential for the maintenance of bone mass in postmenopausal women with Addison's disease. In addition, these data indicate that the small amounts of androgens secreted by the adrenal cortex have a role in the maintenance of bone mass in normal postmenopausal women.

Osmoregulation of arginine-8-vasopressin secretion in primary hypothyroidism and in Addison's disease

The osmoregulation of arginine-8-vasopressin (AVP) was investigated in 14 patients with primary hypothyroidism and in 6 with Addison's disease. Plasma AVP was measured by radioimmunoassay. Patients with primary hypothyroidism were classified into subgroups with elevated (6.81 +/- 1.12 pmol/l) or normal (3.92 +/- 0.96 pmol/l) basal levels of plasma AVP. Following the infusion of 2.5% saline, a positive correlation was established between plasma AVP and plasma osmolality. A decreased osmotic threshold was found in hypothyroid patients with augmented basal AVP levels (pAVP = 0.37 (pOs-265), r = 0.71, P less than 0.01) as compared with that in hypothyroid patients with a normal AVP level (pAVP = 0.42 (pOs-280), r = 0.93, P less than 0.001). A relationship was demonstrated between the alteration in the AVP osmoregulation and the severity of the thyroid insufficiency. Patients with Addison's disease exhibited an increased basal level of plasma AVP (9.59 +/- 1.25 pmol/l) and a decreased osmotic threshold (pAVP = 0.42 (pOs-261), r = 0.63, P less than 0.01) contrasted to that of healthy volunteers (pAVP = 0.41 (pOs-280), r = 0.83, P less than 0.001). The osmoregulation disturbance of the AVP secretion may play a major role in the impaired water metabolism in primary hypothyroidism and in Addison's disease.

Elevated levels of plasma atrial natriuretic peptide in Bartter's syndrome fall to normal with indomethacin: implications for atrial natriuretic peptide regulation in man

Plasma atrial natriuretic peptide (ANP) levels were inappropriately elevated in Bartter's syndrome, in contrast with appropriately low levels in patients with Addison's disease and bulimia, with similar hyper-reninaemia and volume contraction. Inappropriate overproduction of ANP in Bartter's syndrome may be important in the pathophysiology. Prostaglandin inhibitors cause sodium retention and might be expected to increase ANP levels, based on their volume effects. Surprisingly, therefore, both indomethacin and aspirin lowered elevated levels of ANP in Bartter's syndrome to normal, indomethacin achieving this within 24 h. Single doses of indomethacin and aspirin also lowered plasma ANP levels in normal subjects. Saline infusion in Bartter's syndrome increased already-elevated levels of ANP further. When repeated during indomethacin treatment, despite suppression of basal levels to normal, even higher levels were achieved in three of four subjects. These results are consistent with a role for prostaglandins in ANP release in man, but suggest that another mechanism is also operative. They may help to explain the variable renal effects of prostaglandin inhibition.

Diurnal rhythms of proopiomelanocortin-derived N-terminal peptide, beta-lipotropin, beta-endorphin and adrenocorticotropin in normal subjects and in patients with Addison's disease and Cushing's disease

In order to clarify the diurnal pattern of secretion of plasma immunoreactive (IR) proopiomelanocortin (POMC)-derived peptides, IR-N-terminal peptide (Nt), IR-beta-endorphin (Ep), IR-beta-lipotropin (LPH), and IR-ACTH (ACTH) in normal subjects and in patients with Addison's disease and Cushing's disease, we measured these 4 peptides in the same plasma obtained at 0900 h and then every three hours until 0600 h at the next day. All four peptides showed diurnal rhythms with the peaks at 0600 h, and the nadirs of ACTH, LPH, Ep and Nt were at 0000 h, 0000 h, 1800 h and 0300, respectively in normal subjects. In patients with Addison's disease, these four peptides also showed diurnal rhythms with the peaks at 0600 h for ACTH and Ep and at 0900 h for LPH and Nt, and the nadirs at 2100 h for ACTH and Ep and at 0000 h for LPH and Nt. The molar ratios of Ep/ACTH, LPH/ACTH and Nt/ACTH in plasma also presented diurnal variations in normal subjects and in patients with Addison's disease. On the other hand, in patients with Cushing's disease, ACTH, LPH and Nt showed no rhythmicity or change in molar ratios of Ep/ACTH, LPH/ACTH or Nt/ACTH. Only Ep showed diurnal variation. The molar ratios of Ep/ACTH, LPH/ACTH and Nt/ACTH in patients with Cushing's disease were significantly higher than those in normal subjects and in patients with Addison's disease at 0000 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma immunoreactive proopiomelanocortin peptides and cortisol in normal dogs and dogs with Addison's disease and Cushing's syndrome: basal concentrations

We measured basal plasma concentrations of the immunoreactive (IR) proopiomelanocortin (POMC)-derived peptides ACTH, beta-lipotropin (beta LPH), beta-endorphin (beta END), and alpha MSH in 160 normal dogs, 32 dogs with Addison's disease, 42 dogs with adrenocortical tumors causing Cushing's syndrome, and 169 dogs with pituitary-dependent Cushing's disease. In normal dogs, plasma IR-POMC peptide levels were similar to those in man, except that IR-alpha MSH, a pars intermedia POMC product, was readily detected. In Addisonian dogs, plasma cortisol was decreased, and the IR-POMC peptides were increased, except for IR-alpha MSH, which was normal. In 7 Addisonian dogs given dexamethasone, elevated plasma IR-ACTH, beta LPH, and beta END levels fell dramatically. In dogs with Cushing's syndrome due to adrenal tumors, plasma IR-ACTH, beta LPH, and beta END were decreased, and cortisol was increased, but IR-alpha MSH was normal. Dogs with Cushing's disease due to pars distalis tumors had elevated plasma IR-ACTH, beta LPH, beta END, and cortisol, but normal IR-alpha MSH; their plasma cortisol was suppressed by dexamethasone. There appeared to be 2 types of pars intermedia tumors causing Cushing's disease: 1 dexamethasone nonsuppressible and with disproportionately high plasma IR-alpha MSH levels, the other relatively dexamethasone suppressible and with normal to slightly elevated IR-alpha MSH levels. These 2 pars intermedia tumor types may arise from 2 distinct normal canine pars intermedia cell types. Canine Cushing's disease may provide a useful model for variants of the disorder in man.

Response of total and 'free' thyroid hormones and diiodotyrosine to bovine TSH in subclinical hypothyroidism

Thirty-three patients with Addison's disease were studied. Twenty-two had idiopathic Addison's disease; within this group, 14 patients had clinical or subclinical hypothyroidism, and 16 had increased titres of thyroid autoantibodies. Five patients had tuberculous, and eight had unclassifiable Addison's disease; only one patient in the latter group had evidence of thyroid autoimmunity. A stimulation test with 15 mU bTSH/kg was performed in three patients with Schmidt's syndrome (coexisting Addison's disease and manifest primary hypothyroidism), 15 patients with either subclinical hypothyroidism or increased titres of thyroid autoantibodies, 10 patients without thyroid involvement, and 10 normal controls. There was no detectable increase of 'free' and total thyroid hormones in Schmidt's syndrome. The mean increases after 3-4 h of T4, fT4, T3 and fT3 were 22, 35, 63 and 66%, respectively, in patients without thyroid involvement, and 13, 24, 46 and 45% in patients with subclinical hypothyroidism. 'Free' but not total thyroid hormones rose significantly (P less than 0.01) higher in patients without signs of thyroid involvement than in patients with subclinical hypothyroidism and/or thyroid autoantibodies. Thyroid hormone response to bTSH in Addison's disease with apparently healthy thyroid glands was not different from normal controls. Serum diiodotyrosine rose in all groups except in hypothyroidism; hypothyroid patients had, however, basal levels well within the normal range. Thus, thyroid hormone synthesis appears to be blocked at a point distal to diiodotyrosine formation in this particular situation. These results support the assumption that TSH elevation in idiopathic Addison's disease is due to coexisting thyroid autoimmunity and that it reflects incipient thyroid failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Responsiveness of hypophyseal-adrenocortical axis to repetitive administration of synthetic ovine corticotropin-releasing hormone in patients with isolated adrenocorticotropin deficiency

The primary lesion site in isolated ACTH deficiency was studied in three patients by examining the responses of immunoreactive ACTH to insulin-induced hypoglycemia, lysine vasopressin, and synthetic ovine corticotropin-releasing hormone (CRH). In all patients, no significant changes in immunoreactive ACTH followed insulin-induced hypoglycemia or lysine vasopressin. Fifty micrograms (greater than or equal to 1 microgram/kg BW) of CRH administered as an iv bolus dose daily for 6 consecutive days elicited no significant increase in plasma immunoreactive ACTH, beta-lipotropin, or cortisol levels in all patients. Eight iv bolus injections of 0.63 microgram/kg BW CRH at 4-h intervals also failed to induce a significant response of immunoreactive ACTH to an iv bolus dose of 1 microgram/kg CRH at 36 h in one patient. In contrast, a single bolus dose of 50 micrograms CRH induced a response of plasma immunoreactive ACTH in a patient with Cushing's disease and a patient with Addison's disease. The present results suggest that the primary lesion of isolated ACTH deficiency is not the hypothalamus, but, rather, is located in pituitary ACTH-secreting cells.

Effect of prolonged administration of CRF on plasma concentrations of ACTH in patients with Addison's disease

To investigate the possibility that the prolonged administration of corticotropin releasing factor (CRF) might suppress rather than enhance pituitary ACTH-secretion 24-hour infusions (50 micrograms/h) of ovine CRF were performed in 6 patients with adrenocortical insufficiency. CRF induced a heterogeneous behaviour of plasma ACTH concentrations in these hypercorticotropinemic patients but both a sustained increase and a suppression of ACTH was clearly absent at the end of the 24 hour infusion period. Thus, continuous administration of CRF does not appear to be a promising way to control abundance of plasma ACTH concentrations in patients with Addison's disease.

Loperamide, an opiate analogue, inhibits plasma ACTH levels in patients with Addison's disease

The effects of loperamide, an opiate analogue of the piperidine class on pituitary hormone secretion were evaluated in eight patients with Addison's disease. In all patients loperamide administration (16 mg orally) induced a marked fall in plasma ACTH levels (P less than 0.01), without affecting GH, PRL and LH levels. Plasma ACTH concentration fell significantly from 854 +/- 167 pg/ml (mean +/- SEM) to 460 +/- 123 pg/ml at 60 min (P less than 0.01). The inhibition persisted throughout the whole test period, the nadir being reached at 300 min. Low dose naloxone infusion 180 min after loperamide administration caused plasma ACTH to rise from 181 +/- 61 pg/ml to 539 +/- 99 pg/ml (P less than 0.01). The present data suggest that the opiate analogue loperamide is a potent inhibitor of ACTH secretion in patients with Addison's disease, which may be acting on mu receptors, since its effect is blocked by low doses of naloxone.

Effect of angiotensin II on plasma ACTH in patients with Addison's disease

Short-term angiotensin II (AII) infusions (3 ng/kg/min) were performed in 5 patients with Addison's disease in order to assess the effect of AII on ACTH secretion. Base line ACTH levels were elevated due to a 9-h time lag between hydrocortisone administration and onset of the study. In 2 separate infusion periods of 30-min duration, AII had no unidirectional effect on plasma ACTH. Mean ACTH increased slightly but insignificantly. Mean blood pressure rose by about 10 mmHg. The degree of angiotensinaemia induced is probably similar to the state of moderate to severe sodium deficiency. Short-term changes of AII in this order of magnitude have obviously no major effect on ACTH secretion.

Evidence against a self-inhibition of ACTH secretion in man

To ascertain the physiological relevance of an autoregulation of adrenocorticotropin hormone(ACTH) secretion in man, we studied the effect of alsactide (beta-Ala1, Lys17-ACTH1-17-4-amino-N-butylamide), a synthetic ACTH analogue with potent steroidogenic activity but not recognized in the endogenous ACTH immunoassay, on plasma ACTH pattern in patients with Addison's disease. Three experimental models were employed as follows: (a) in 6 patients, whose steroid replacement therapy had been discontinued 36 h previously, we compared the effect of alsactide, administered at two dose levels (10 or 100 micrograms i.v. als bolus followed by the same dose infused over 2 h, and of placebo, on the plasma ACTH pattern; (b) the previous experiment was repeated in 4 patients in whom cortone replacement therapy was substituted for 3 days with dexamethasone, 0.5-1.5 mg daily p.o., so as to lower plasma ACTH levels to within the high normal range; (c) in 4 patients off therapy for 36 h, we evaluated the ACTH response to synthetic ovine corticotropin-releasing factor, 1 microgram/kg body weight injected intravenously, occurring during concomitant administration of alsactide, 100 micrograms i.v. as bolus plus 100 micrograms infused over 2 h, or placebo. Compared to placebo, alsactide did not significantly affect the pattern of ACTH under any of the experimental conditions investigated. Collectively, our findings, although they have to be interpreted with caution, do not support the idea that a self-regulation mechanism plays an important role in the control of ACTH secretion in man.

On the stability in vitro of bioactive human adrenocorticotrophin in blood and plasma

The disappearance in vitro of ACTH from whole human blood and plasma held at 22 degrees C has been monitored using a dispersed adrenal cell bioassay and an unextracted radioimmunoassay. In three normal subjects after a metyrapone test and two patients with Addison's disease, endogenous bioactive ACTH levels were unchanged for at least 1 h in blood and 2 h in plasma. Moreover greater than 50% of the bioactive plasma ACTH was still present in the plasma samples from the patients with Addison's disease after 24 h incubation at ambient temperatures. Human pituitary ACTH (1-39), spiked into plasma from dexamethasone suppressed subjects to give a concentration of 250 ng/l, was stable by bioassay for at least 2 h. No loss of biological activity was observed on subjecting plasma from a patient with Addison's disease or spiked plasma to two cycles of thawing at 37 degrees C and freezing at -70 degrees C or thawing at 20 degrees C and freezing at -20 degrees C. Some loss of bioactivity (20%) occurred on subjecting the patient's, but not ACTH-spiked plasma to four cycles of thawing at 20 degrees C/freezing at -20 degrees C. We conclude that bioactive ACTH (endogenous or exogenous) may be more stable in vitro in human blood and plasma than has been previously thought. If our studies can be confirmed in a larger series then it may be that conditions for handling blood specimens for ACTH assays could be reappraised.

High serum levels of angiotensin-converting enzyme in untreated Addison's disease

Serum angiotensin-converting enzyme (ACE) in four patients with untreated Addison's disease was significantly higher [79.7 +/- 17.5 (SD) nmol min-1 ml-1] than in normal subjects (37.7 +/- 8.9 nmol min-1 ml-1, P less than 0.02). During corticosteroid hormone replacement therapy the enzyme levels returned within the normal range (44.0 +/- 7.6 nmol min-1 ml-1). In two additional patients the enzyme was assayed only while they were receiving therapy and found normal (38 and 52 nmol min-1 ml-1, respectively). In one of them, an increase ACE level (70 nmol min-1 ml-1) was found after therapy was reduced by 50%. Primary adrenal insufficiency is another disease in which ACE levels may be increased.

ACTH and cortisol responses to ovine corticotrophin-releasing factor in patients with primary and secondary adrenal failure

The ACTH and cortisol responses to an intravenous bolus injection of 100 micrograms ovine CRF were studied in 19 patients with adrenal failure. In all eight patients with primary adrenal failure, plasma ACTH levels increased from a mean basal level of 1494 +/- 431 (SEM) pg/ml to peak value of 2601 +/- 1220 pg/ml at 10 min. In comparison with healthy subjects absolute ACTH increments after ovine CRF were significantly augmented in the patients with Addison's disease (P* less than 0.001), and the absolute ACTH responses after ovine CRF were positively correlated with the basal plasma ACTH levels. The 11 patients with secondary adrenal insufficiency could be subdivided into two groups: (A) those having little or no ACTH and cortisol response to ovine CRF (five patients) and (B) those having prolonged and pronounced ACTH responses with a biphasic pattern and a delayed second peak (six patients), followed in all patients by a marked cortisol increase. These data demonstrate that the CRF-test can discriminate between hypothalamic and pituitary causes of secondary adrenal failure.

Rifampicin-induced adrenal crisis in addisonian patients receiving corticosteroid replacement therapy

Rifampicin induced profound alterations in cortisol metabolism when administered to three patients with primary adrenal failure receiving adequate corticosteroid replacement therapy. In one patient, adrenal crisis was precipitated after the institution of rifampicin therapy for treatment of coexistent tuberculosis and in another, profound asthenia, decrease in blood pressure, hyperkalemia, and hyponatremia developed during the hydrocortisol kinetic study. The clinical symptoms subsided and the electrolyte abnormalities were corrected approximately 7 days after rifampicin withdrawal. The half-life of hydrocortisol and the area under the curve were decreased by 35% and 23%, respectively, whereas the systemic clearance was increased by 35% during rifampicin administration. It appears, that the effectiveness of glucocorticoids and mineralocorticoids were greatly impaired by rifampicin administration due to induction of liver steroid-metabolizing enzymes. It is strongly recommended that in patients with compromised adrenal function, treatment with rifampicin must be accompanied by doubling or tripling the dose of adrenal steroids to maintain adequate steroid replacement therapy.

Auto-immune Addison's disease associated with hyperprolactinaemia

Four cases of auto-immune Addison's disease are reported in association with hyperprolactinaemia. Two of the females had galactorrhoea. In three cases complete resolution of hyperprolactinaemia occurred with corticosteroid replacement, but it was only partial in the fourth. We suggest that hyperprolactinaemia was due to cortisol deficiency operating directly or indirectly at the level of the pituitary. These data support the animal and in vitro evidence for the influence of corticosteroids on prolactin release.

Acute effects of mazindol on the secretion of ACTH, beta-lipotropin, beta-endorphin and cortisol in man

The effects of mazindol, an anorexiant, on the secretion of anterior pituitary and adrenocortical hormones were examined in healthy male volunteers and in patients with Addison's disease. In healthy male volunteers, significant elevations in plasma ACTH, beta-endorphin, beta-lipotropin and growth hormone were induced by mazindol administration, though no changes were observed in plasma thyrotropin, luteinizing hormone, follicle-stimulating hormone or prolactin. Plasma ACTH increased in patients with Addison's disease, too. In addition, plasma cortisol increased, without a change in the plasma aldosterone levels after mazindol administration to normal subjects.

Human plasma proopiomelanocortin N-terminal peptide and adrenocorticotropin: circadian rhythm, dexamethasone suppression, and corticotropin-releasing hormone stimulation

The circadian rhythm, suppression with dexamethasone, and stimulation by corticotropin-releasing hormone (CRH) of plasma immunoreactive (IR) proopiomelanocortin N-terminal (NT) and IR-ACTH were studied in nine normal subjects and two patients with Addison's disease. The RIA for human NT (hNT) used was specific for NT except for partial cross-reactivity with gamma 2MSH. In normal subjects, plasma IR-hNT and IR-ACTH had almost parallel circadian rhythms and were suppressed by dexamethasone. The mean plasma levels of IR-hNT and IR-ACTH at 0800 h were 140 +/- 23 (SD) and 23 +/- 5 pg/ml, respectively. Plasma IR-hNT increased in parallel with IR-ACTH 15 to 30 min after iv injection of 100 micrograms ovine CRH. Maximum percent increases in plasma IR-hNT and IR-ACTH were 185 +/- 47 and 235 +/- 10%, respectively. In Addison's disease, on the other hand, plasma levels of IR-hNT and IR-ACTH were markedly elevated and the circadian rhythms were parallel. The mean plasma IR-hNT and IR-ACTH levels at 0900 h were 4363 and 1750 pg/ml, respectively. These results suggest that plasma hNT and ACTH are produced from a common precursor in the pituitary gland and secreted concomitantly under various physiological conditions such as stimulation by CRH and inhibition by glucocorticoid.

Rapid and specific radioimmunoassays for beta-endorphin and beta-lipotropin in affinity-purified human plasma

Using rapid and reusable affinity columns, we established a method to measure beta-endorphin (beta END) and beta-lipotropin (beta LPH) separately in human plasma. One column contained antibodies against the N-terminal portion of beta LPH, and the other contained antibodies against beta END. The first column separated beta LPH from beta END and concentrated beta LPH as well, and the second separated beta LPH from concentrated beta END. Mean plasma levels (at 0830-0930 h) of beta END and beta LPH in 10 normal subjects were 1.1 +/- 0.1 (+/- SE) and 4.1 +/- 0.4 fmol/ml, respectively; both were markedly elevated in patients with ACTH/LPH hypersecretory states. The molar ratios of plasma levels of beta END and beta LPH were fairly constant in normal subjects (0.28 +/- 0.01), unchanged in patients with Cushing's disease and Cushing's disease after adrenalectomy, lower in patients with Addison's disease (P less than 0.001), higher in patients with chronic bone pain (P less than 0.001), and variable in patients with the ectopic ACTH syndrome. These data indicate that beta END and beta LPH can be measured separately in plasma by simple and reproducible procedures.

A sensitive direct enzyme immunoassay for cortisol in plasma and saliva

A sensitive enzyme immunoassay for cortisol in plasma and saliva without extraction has been developed. An antibody was raised in rabbits against cortisol-3-CMO-BSA and compared with anti-cortisol-21-HS-HSA. The enzyme label was a covalently linked cortisol-horseradish peroxidase conjugate. Solvent extraction was avoided by use of heat denaturation of transcortin and dilution of plasma 1:300. This assay had a limit of detection of 3 fmol/tube and satisfied the standard criteria of accuracy and precision. The test requires only a simple photometer. The normal values of cortisol in plasma and saliva before and after ACTH, dexamethasone or metyrapone application were determined. Saliva, being easily collected by a noninvasive, stress-free technique is an alternative to plasma. The cortisol concentrations were significantly increased in plasma and saliva of patients with Cushing's syndrome and decreased in patients with Addison's disease.

Preliminary experiences with a bioassay for adrenocorticotrophin (ACTH) in unextracted human plasma using dispersed guinea-pig adrenal cells

A simple, accurate and precise dispersed cell bioassay suitable for the assay of ACTH levels greater than 50 ng/1 in unextracted human plasma is described. Isolated adrenal cells were prepared by tryptic digestion of the guinea-pig adrenal gland and cortisol production by these cells was controlled specifically by ACTH. The cortisol response to 2 ng/1 of human pituitary ACTH (1-39) was always significantly (P less than 0.05, n = 17) different from the control. ACTH concentrations between 1 and 20 ng/1 gave a 14 +/- 3 fold (n = 17) increment in cortisol response. Dilutions of test plasmas were parallel with standard ACTH (1-39) when the plasma concentrations were maintained throughout at 4% (1 in 25 dilution) by the addition of dexamethasone-suppressed plasma ('ACTH free'). Using a 25 fold plasma dilution, the limit of detection of ACTH in unextracted plasma was 50 ng/1. Recovery of ACTH (1-39) spiked into dexamethasone suppressed plasma at concentrations of 250 and 100 ng/1 was 97 +/- 10% (n = 17) and 114 +/- 15% (n = 17) respectively. The within assay coefficient of variation (CV) of both quality control and patients' samples never exceeded 9% while between assay variation was less than or equal to 13%. The sample throughput was 30 plasma samples/week/technician.

Enzyme immunoassay for serum 18-hydroxycorticosterone and its clinical application

An enzyme immunoassay for serum 18-hydroxycorticosterone was established using alkaline phosphatase as a label. The antiserum for 18-hydroxycorticosterone was produced by immunization of rabbits with 18-hydroxycorticosterone 3-(O-carboxymethyl)oxime conjugated to bovine serum albumin. Sephadex LH-20 column chromatography was used to separate 18-hydroxycorticosterone from other steroids in serum samples. The minimal detectable amount of 18-hydroxycorticosterone was 50 pg/tube and the measurable range was from 5 to 1000 ng/dl when a 1.0 ml serum sample was used. Intra- and inter-assay coefficients of variance were 5.0% (n = 6) and 5.8% (n = 6), respectively. Four of 5 patients with aldosterone-producing adenoma had above-normal serum 18-hydroxycorticosterone levels.

Lack of ACTH lowering effect of sodium valproate in patients with ACTH hypersecretion

The effect of an oral dose of 200 or 400 mg sodium valproate (DPA) on ACTH and cortisol secretion was assessed in 11 patients with Cushing's disease (3 bilaterally adrenalectomized), 3 patients with Nelson's syndrome and 6 patients with Addison's disease. In none of the patients examined DPA induced changes in ACTH (and cortisol) levels appreciably different from the fluctuations recorded after placebo administration. The effect of a long term administration of sodium valproate (600-1000 mg/day) was evaluated in 2 patients with active Cushing's disease and in 1 patient with Nelson's syndrome (3 weeks, 3, 9 months respectively); in the 2 patients with Cushing's disease ACTH and cortisol secretion, 17-hydroxy-corticosteroids (17-OHCS) urinary excretion did not change during DPA treatment. Similarly the cortisol response to hypoglycemia and the 17-OHCS urinary excretion after dexamethasone were not normalized. Long term DPA administration did not induce either clinical or hormonal modifications in the patient with Nelson's syndrome. These findings do not support the possibility that a deficiency of a GABAergic system plays a role in the pathogenesis of ACTH hypersecretion. DPA does not seem to be of therapeutical value in the medical management of Cushing's disease and Nelson's syndrome.

Corticotropin-releasing factor test in normal subjects and patients with hypothalamic-pituitary-adrenal disorders

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.

Effects of sodium-valproate administration on plasma ACTH levels in patients with ACTH hypersecretion

The effects of the acute administration of sodium-valproate (400 mg po) on plasma ACTH levels were studied in 4 patients with Cushing's disease, 1 with Nelson's syndrome and in 3 with Addison's disease. No significant reduction of corticotropin concentration was observed, as compared to saline infusion. These data do not favor the hypothesis of an inhibitory role of sodium-valproate on ACTH secretion in such patients.

Studies on cortisol substitution therapy in patients with adrenal insufficiency

To eight patients with Addison's disease 25 mg of cortisone acetate or cortisol, respectively, was given orally. Thereafter blood samples were taken and analysed for total cortisol, "free" (not protein bound) cortisol and ACTH. Furthermore, urine cortisol excretion and the cortisol binding capacity of the plasma were determined. We found that after the substitution therapy the increase of the plasma cortisol was variable and reached its maximum after 45 to 240 minutes. However, if the resorption time was subtracted the individual differences were less pronounced and plasma cortisol levels above 8 micrograms/dl could be maintained for about six hours. When cortisol was taken instead of cortisone acetate the increase of the plasma cortisol was steeper, decreasing then more rapidly. Plasma "free" cortisol ranged from 2.75 to 6.19% in relation to total cortisol and closely paralleled the level of total cortisol in each patient during the course of the experiment. The excretion of unconjugated cortisol in urine amounted to 56.5 +/- 26 micrograms (SE) and was better correlated to the concentration of "free" cortisol than to total plasma cortisol. The behaviour of plasma ACTH levels was variable. Great fluctuations with high morning levels and good suppression was observed in patients having their substitution tablet only in one single morning dose. From these biochemical data recommendations for the substitution therapy in patients with adrenal insufficiency were given.

Erythrocyte insulin receptors and insulin sensitivity in adrenocortical insufficiency. Report of a case of diabetes mellitus type I with superimposed Addison's disease

Studies on erythrocyte insulin receptors were performed in a boy with type I diabetes mellitus and superimposed adrenocortical insufficiency before and during treatment with hydrocortisone and 9-alpha-fluorohydrocortisone. The development of the adrenal insufficiency was associated with a progressively increased sensitivity to insulin which reverted after therapy. The maximum specific insulin binding of the erythrocytes was low during threatening addisonian crisis (6.9%) but normalized during hydrocortisone treatment (12.0%). These findings suggest that the increased insulin sensitivity characteristic for adrenocortical insufficiency is not an effect of an increased insulin receptor concentration and that hypocortisolaemia is associated with a down-regulation of the insulin receptors.

Active and inactive renin in primary and secondary adrenal insufficiency and during ACTH infusion

Prolonged low-dose ACTH infusion leads to a transient stimulation of plasma renin activity (PRA) and angiotensin II.

In part 1 of the present study (infusion of 10 IU of ACTH per day for 38 h into 6 normal young males), it was shown that the concentration of active renin (aPRC) increases in parallel to PRA. Thus, the rise in PRA is either due to net active renin secretion by the kidney or to increased conversion of inactive into active renin. Since the plasma concentration of inactive renin (iPRC) tended to rise rather than to fall during ACTH infusion, peripheral activation of inactive renin is probably not the cause of the rise in aPRC.

Part 2 of the study consisted in the measurement of plasma ACTH, cortisol, PRA, aPRC and iPRC in 10 patients (group I) with primary adrenocortical insufficiency (8 Addisonians, 2 adrenalectomized Cushing's) and in 9 patients with hypopituitarism (group II) after short-term withdrawal of hydrocortisone substition therapy. ACTH was 1770 ± 390 pg/ml in the former and 20 ± 4 pg/ml in the latter group. PRA and aPRC were higher and the ratio iPRC:aPRC lower in group I than in group II. This might indicate stimulation of active renin formation by ACTH. However, it is unlikely that the higher aPRC levels in group I are due to increased peripheral activation of inactive renin, since the relationship between aPRC and the ratio iPRC:aPRC fell on the same curve in both groups.

ACTH or an ACTH-dependent mechanism raises aPRC, probably by stimulating its renal secretion rather than by peripheral activation of inactive renin.

[Molecular forms of pituitary and plasma ACTH in physiology and pathology]

Immunoreactive ACTH has been found in human pituitary and plasma under different molecular forms: Big ACTH, intermediate ACTH, ACTH 1-39 and fragments of ACTH. In the literature, there are some controversies especially regarding to the importance of Big ACTH in plasma and tissue. Big ACTH is absent or present in only low amounts in plasma and pituitary extracts from normal subjects. However, the proportion of Big ACTH is very high in tumor extracts and plasma obtained from patients with ectopic ACTH syndrome High concentrations of small ACTH fragments are also present in this syndrome.

Inhibitory effect of cyproheptadine on ACTH secretion in patients with Addison's disease

In 14 patients with Addison's disease plasma levels of ACTH were studied after administration of a single oral dose (16 mg) of cyproheptadine. The drug administration was followed by an inhibition of ACTH release. These results support the view that cyproheptadine may exert an inhibitory effect on ACTH secretion in subjects whose corticosteroid feedback mechanism is normal. We hypothesize that the effect of cyproheptadine might be related to its anti-serotonin or anti-histaminergic action.

Hypercalcemia associated with hypoadrenocorticism in sixteen dogs

During a 3-year-period, hypercalcemia was found in 16 (28%) of 62 dogs with hypoadrenocorticism. Thirteen of the dogs were hypercalcemic at the time of diagnosis, whereas hypercalcemia developed at relapse during maintenance corticosteroid therapy in 3 dogs. The severity of hypercalcemia correlated with the severity of hypoadrenocorticism. Clinical signs and biochemical disturbances were more severe and mean calcium concentration was significantly higher in the dogs that were hypercalcemic at time of diagnosis than in the dogs that became hypercalcemic while on therapy. In all dogs, the high calcium concentration promptly and completely resolved with adequate corticosteroid replacement therapy.

ACTH suppression after oral administration of cortisone in Addisonian and adrenalectomized patients

Plasma cortisol and the corresponding ACTH concentrations were determined before, and for 6 h following a single oral dose of 25 mg cortisone acetate in 7 patients with Addison's disease, 6 patients adrenalectomized for Cushing's disease and 1 patient adrenalectomized for congenital adrenal hyperplasia. The basal plasma cortisol concentrations 12 h after an evening dose of cortisone acetate 12.5 mg were below 100 nmol/l, and the corresponding ACTH concentrations were markedly elevated in all patients. Great interindividual variations were found in cortisol peak concentrations (Cmax) and the time to peak values, but without significant differences between the two patient groups. The maximal ACTH suppression occurred within 60-330 min after the cortisol Cmax, and was not significantly different in the two groups. The suppressed plasma ACTH concentrations were considerably above normal in 3 of the patients with Addison's disease and in 4 of the 6 patients adrenalectomized for Cushing's disease, including 2 patients with Nelson's syndrome. A similar degree of impaired ACTH suppression in patients with Addison's disease as in adrenalectomized patients suggests the occurrence of a secondary hypothalamic-pituitary dysfunction with ACTH hypersecretion in Addison's disease. The adequacy of the commonly used adrenocortical replacement therapy and its possible relation to the impaired ACTH suppression is discussed.

Effects of a met-enkephalin analog on adrenocorticotropin (ACTH), growth hormone, and prolactin in patients with ACTH hypersecretion

The effect of D-Ala2, MePhe4, Met-(0)enkephalinol (Sandoz FK 33-824; 0.5 mg, im) on pituitary hormone secretion was studied in 11 patients with Addison's disease and 11 patients with ACTH-dependent Cushing's disease. In patients with Addison's disease, a pronounced fall of plasma ACTH levels was observed (P less than 0.005). The ACTH response to FK 33--824 was partially reversed by naloxone (4 mg, iv). In patients with Cushing's disease, no unequivocal decrease in either ACTH or cortisol was seen. Moreover, FK 33--824 failed to influence the vasopressin-induced ACTH increase in 5 patients with Cushing's disease. In patients with cortisol deficiency due to either Addison's disease or bilateral adrenalectomy for Cushing's disease, FK 33--824 led to increases in PRL and GH similar to those described in normal subjects. However, in the presence of longstanding hypercortisolism, the PRL increase was significantly diminished, and the GH response to FK 33--824 was completely abolished. Our results suggest that in Addison's disease ACTH release is influenced by inhibitory opiate receptors. In patients with Cushing's disease, ACTH secretion is insensitive to FK 33-284, presumably because of an autonomous pituitary adenoma or hypothalamic derangement. The impairment of the PRL and GH responses to FK 33--824 in Cushing's syndrome seems to reflect a direct action of the elevated cortisol level, for it is not seen after bilateral adrenalectomy.

ACTH-producing pituitary adenomas in Addison's disease: two cases treated by transsphenoidal microsurgery

In 2 women with known Addison's disease, progressive hyperpigmentation reappeared years after an initial remission under conventional substitution therapy with cortisone. Excessively elevated plasma ACTH concentrations and radiological evidence of sella turcica deformation led to the diagnosis of ACTH-producing adenomas and prompted their removal by transsphenoidal microsurgery. In one patient, a large Crooke's cell adenoma with extensive extrasellar expansion had caused severe and irreversible bilateral defects of the visual fields and unilateral optic atrophy. Surgical removal of the tumour and radiotherapy brought about a permanent disappearance of the hyperpigmentation, but eventually led to secondary hypothyroidism. In the second patients, the selective removal of a small intrasellar eosinophilic adenoma consisting of ACTH-producing cells did not alleviate the hyperpigmentation and did not lower the plasma ACTH concentration. However, hyperpigmentation regressed markedly within a year of treatment with a higher dose of cortisone. The rarity of similar cases in the literature seems to indicate that insufficient feedback suppression of ACTH-producing cells in treated Addison's disease does not by itself induce the development of a pituitary adenoma, but might promote the growth of an independently and coincidentally occurring microadenoma, which would have caused Cushing's disease in a person with intact adrenal glands.

Acute suppressive effect of ACTH-induced cortisol secretion on serum prolactin levels in healthy man

The effect of ACTH on serum prolactin concentrations was studied in 6 healthy women in the follicular phase of the menstrual cycle, in 5 healthy men and in 6 patients (5 males, 1 female) with adrenocortical insufficiency. In healthy women prolactin levels decreased from basal, 14.4 +/- 2.1 (SEM) microgram/l to 9.4 +/- 0.9 microgram/l after 30 min and to 8.1 +/- 0.7 micrograms/l after 60 min of iv administration of synthetic ACTH1-24 (0.25 mg). Upon continuous infusion of ACTH1-24 (0.25 mg for 8 h) prolactin fell to 4.4 +/- 0.6 microgram/l in healthy women and to 4.6 +/- 1.5 micrograms/l (basal: 10.6 +/- 1.8 micrograms/l) in healthy men. In patients with adrenocortical insufficiency prolactin concentrations remained unchanged following an 8 h infusion of ACTH1-24 (before ACTH: 14.5 +/- 2.3 micrograms/l, after ACTH: 16.3 +/- 3.1 micrograms/l). After treatment with dexamethasone (2 mg/day for 3 days) however, prolactin concentrations were suppressed both in healthy women (-52 +/- 7%) and men (-25 +/- 11%) and in patients with adrenocortical insufficiency (-21 +/- 10%). Thus the effect of ACTH on prolactin appeared to be mediated via enhanced cortisol secretion. It is suggested that an acute increase in cortisol levels within the physiological range may modulate prolactin secretion.