PLASMA ACTH IN NORMAL SUBJECTS AND CUSHING PATIENTS FOLLOWING METOPIRONE (SU 4885) ADMINISTRATION

1962 ◽  
Vol 40 (3_Suppl) ◽  
pp. S74 ◽  
Author(s):  
E. F. Pfeiffer ◽  
F. Garmendia ◽  
E. Vaubel
Keyword(s):  
Normal Subjects ◽  
Plasma Acth

NEGATIVE, RATE-SENSITIVE FEEDBACK EFFECTS ON ADRENOCORTICOTROPHIN SECRETION BY CORTISOL IN NORMAL SUBJECTS

1982 ◽  
Vol 92 (3) ◽  
pp. 443-448 ◽  
Author(s):  
S. C. J. READER ◽  
J. ALAGHBAND-ZADEH ◽  
J. R. DALY ◽  
W. R. ROBERTSON
Keyword(s):  
Negative Feedback ◽  
Feedback Inhibition ◽  
Fast Rate ◽  
Normal Subjects ◽  
Constant Infusion ◽  
Stress Tests ◽  
Nacl Solution ◽  
Plasma Acth ◽  
Acth Secretion ◽  
Feedback Effects

Plasma ACTH and corticosteroid levels were measured in normal subjects during constant infusion of either 0·9% (w/v) NaCl solution or cortisol, and during insulin-induced hypoglycaemia. During infusions of 0·9% NaCl solution the secretion of ACTH and corticosteroids was episodic. Fast, rate-sensitive, negative feedback inhibition of ACTH secretion was observed during cortisol infusions, when the corticosteroid levels were within the physiological range (200–750 nmol/l) and were rising at a rate of between 5 and 10 nmol/l per min for 30 min or longer. When plasma corticosteroid levels were in a steady state, the initial fast feedback effects were abolished and ACTH secretion resumed. However, this recovery of ACTH secretion was not seen when the corticosteroid levels were persistently above 800 nmol/l. It appears that corticosteroid-induced negative feedback in man may be both rate- and level-sensitive. During insulin stress tests ACTH secretion fell at a time when the plasma corticosteroid level was rising rapidly (> 5 nmol/l per min) despite persistent hypoglycaemia.

EFFECTS OF ADMINISTRATION OF METOPIRON AND OF DELIVERY ON HUMAN PLASMA CORTICOTROPHIN

1965 ◽  
Vol 48 (4) ◽  
pp. 581-586
Author(s):  
Tore H:son Holmdahl
Keyword(s):  
Human Plasma ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Normal Subjects ◽  
Pituitary Tumour ◽  
Plasma Acth ◽  
Normal Delivery ◽  
Do So

ABSTRACT The ACTH activity of human peripheral blood was assayed during two types of stimuli: 1) administration of SU-4885 (Metopiron® CIBA), 2) normal delivery. Metopiron produced an increase of plasma ACTH activity in 3 normal subjects but failed to do so in 1 case of pituitary tumour. Of the 7 cases of normal delivery studied, 4 showed a significant increase in plasma ACTH activity at the time of delivery.

Vasoactive intestinal polypeptide enhances ACTH levels in some patients with adrenocorticotropin - secreting pituitary adenomas

1987 ◽  
Vol 116 (2) ◽  
pp. 216-220 ◽  
Author(s):  
Bruno Ambrosi ◽  
Domenico Bochicchio ◽  
Alessandro Sartorio ◽  
Francesco Morabito ◽  
Giovanni Faglia
Keyword(s):  
Vasoactive Intestinal Polypeptide ◽  
Cushing’S Disease ◽  
Normal Subjects ◽  
Significant Rise ◽  
Cushing's Disease ◽  
Plasma Acth ◽  
Nelson’S Syndrome ◽  
Nelson's Syndrome ◽  
Cortisol Levels ◽  
Intestinal Polypeptide

Abstract. Vasoactive intestinal polypeptide (VIP) was administered (75 μg iv over 12 min) to 14 patients with Cushing's disease, 1 patient with Nelson's syndrome, and 8 normal subjects. VIP induced a significant rise of plasma ACTH levels in 6 patients with Cushing's disease, from a baseline of 13.2 pmol/l (9.9–18.5 pmol/l) to a peak of 24.5 pmol/l (7.7–18.9 pmol/l), median and range (P < 0.05), and in the patient with Nelson's syndrome, from a baseline of 260.9 to 461.3 pmol/l. A significant elevation of cortisol levels was also observed, from a baseline of 567 nmol/l (185–842 nmol/l) to a peak of 727 nmol/l (364–1029 nmol/l); P < 0.05. No modifications in plasma ACTH and cortisol levels were noticed in the other 8 patients with Cushing's disease, or in the normal subjects. In the responsive patients, the median plasma ACTH level reached after VIP was found to be less than that induced by CRH administration. In 2 of the responsive patients, VIP was injected again after successful microadenomectomy and did not then cause changes in ACTH and cortisol concentration. These data demonstrate that VIP specifically stimulates ACTH release in some patients with corticotropinomas but not in normal subjects; the disappearance of such abnormal ACTH responses after successful adenomectomy suggests the presence of specific VIP receptors only on the adenomatous corticotropes.

Effects of an acute calcium load on plasma ACTH, cortisol, aldosterone and renin activity in man

1984 ◽  
Vol 105 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Roland Isaac ◽  
Jean-Paul Raymond ◽  
Muriel Rainfray ◽  
Raymond Ardaillou
Keyword(s):  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Plasma Aldosterone ◽  
Renin Activity ◽  
Cortisol Secretion ◽  
Plasma Acth ◽  
Aldosterone Secretion ◽  
Cortisol Responses ◽  
Calcium Load

Abstract. Plasma adrenocorticotrophin (ACTH), cortisol and aldosterone increased during and after iv administration of calcium gluconate in 4 normal subjects, one patient with hypoparathyroidism and one patient with hypothyroidism. On the other hand, there was a decrease in plasma renin activity but only in the normal subjects. Plasma ACTH and cortisol responses to calcium were abolished whereas plasma aldosterone response persisted in 2 normal subjects pre-treated with dexamethasone. The results observed after calcium administration were compared to those observed after infusion of the solvent only in 6 normal subjects and 4 thyroidectomized patients who were studied twice at 3 day intervals. Plasma ACTH, cortisol and aldosterone were higher when calcium was administered. Plasma renin activity was not statistically different whether or not calcium had been injected in the subjects studied twice. These results demonstrate a direct effect of calcium on ACTH and aldosterone secretion which is not mediated by calcitonin and parathyroid hormone. The stimulatory effect of calcium on cortisol secretion depends on the increase in plasma ACTH.

CLINICAL AND STEROID METABOLIC STUDIES IN FOUR SIBLINGS WITH CONGENITAL VIRILIZING ADRENAL HYPERPLASIA

1966 ◽  
Vol 52 (4) ◽  
pp. 535-549 ◽  
Author(s):  
Kerstin Hall ◽  
Bernt Hökfelt
Keyword(s):  
Blood Pressure ◽  
Plasma Cortisol ◽  
Salt Intake ◽  
Blood Pressure Response ◽  
Normal Subjects ◽  
Sodium Balance ◽  
Plasma Testosterone ◽  
Plasma Acth ◽  
Adrenogenital Syndrome ◽  
Aldosterone Production

ABSTRACT The present studies were concerned with four siblings suffering from congenital adrenogenital syndrome. Their parents were healthy and not closely related. At first examination the age of the patients varied between 10 and 23 years. They all presented a short stature and marked virilization; blood pressure was normal. All four were genetic females. Three of them were brought up as girls, but one clearly showed male identification. The youngest patient was registered as a boy at birth and brought up as such. None of the case histories revealed signs of cortisol deficiency in spite of low plasma cortisol and low urinary cortisol metabolites. Plasma ACTH was high. Both plasma cortisol and plasma ACTH probably showed normal diurnal variation. Pregnanetriol was a predominant urinary steroid metabolite. There was no indication of a significant secretion of 11-deoxycortisol. Under ordinary salt intake, the urinary aldosterone was higher than in normal subjects, possibly in response to the high production of steroids with natriuretic properties. Following treatment with dexamethasone, the urinary aldosterone decreased and so did cortisol tetra-hydro-derivatives, pregnanetriol and pregnanediol, without any influence on sodium balance. Stimulation with ACTH had no effect on aldosterone production, whereas urinary pregnanetriol and pregnanediol increased markedly, concomitant with a tendency to sodium loss. Angiotensin effectively stimulated aldosterone production, whereas rather larger quantities were needed to obtain a blood pressure response. Plasma testosterone was increased to the levels seen in normal males. Following ACTH there was no further increase in blood testosterone, whereas a marked decrease was seen after dexamethasone. Urinary oestrogens were rather high before treatment and decreased in two patients during treatment with dexamethasone, concomitant with the appearance of urinary gonadotrophins.

Auditory Selective Attention in Cerebral-Palsied Individuals

1985 ◽  
Vol 16 (4) ◽  
pp. 260-266 ◽  
Author(s):  
Lee Ann Laraway
Keyword(s):  
Selective Attention ◽  
White Noise ◽  
Normal Subjects ◽  
Auditory Selective Attention ◽  
Normal Individuals ◽  
Significant Difference

The purpose of this study was to determine whether there is a statistically significant difference between the auditory selective attention abilities of normal and cerebral-palsied individuals. Twenty-three cerebral-palsied and 23 normal subjects between the ages of 5 and 21 were asked to repeat a series of 30 items consisting of from 2 to 4 digits in the presence of intermittent white noise. Results of the study indicate that cerebral-palsied individuals perform significantly poorer than normal individuals when the stimulus is accompanied by noise. Noise was not a significant factor in the performance of the normal subjects regardless of age.

The Effect of Stapedectomy on the Loudness of One’s Own Voice

1965 ◽  
Vol 8 (3) ◽  
pp. 223-234 ◽  
Author(s):  
William Melnick
Keyword(s):  
Middle Ear ◽  
Normal Subjects ◽  
Sound Energy ◽  
Loudness Function ◽  
Before And After ◽  
Increased Sensitivity

Five subjects with normal middle ear mechanisms, and otosclerotic patients, before and after stapedectomy, matched the loudness of their voices to the loudness of a 125-cps-sawtooth noise. The results showed loudness matching functions with gradual slopes, less than 1.00, for the normal subjects and the patients prior to stapedectomy. Post-surgically, the loudness function for the patients increased in steepness to considerably more than 1.00. These results are explained, most logically, in terms of increased sensitivity of the altered middle ear to sound energy generated by the listener’s own voice.

Delayed Auditory Feedback with Different Delay Times at Each Ear

1964 ◽  
Vol 7 (4) ◽  
pp. 369-371
Author(s):  
Samuel Fillenbaum
Keyword(s):  
Delay Interval ◽  
Auditory Feedback ◽  
Normal Subjects ◽  
Delayed Auditory Feedback ◽  
Delay Times

Binaurally asynchronous delayed auditory feedback (DAF) was compared with synchronous DAF in 80 normal subjects. Asynchronous DAF (0.10 sec difference) did not yield results different from those obtained under synchronous DAF with a 0.20 sec delay interval, an interval characteristically resulting in maximum disruptions in speech.

Sign in / Sign up

Export Citation Format

Share Document