摘要:

SUMMARYTo determine the role of known secretagogues in the aldosterone response to dopamine blocking agents, plasma levels of ACTH, angiotensin II, potassium and plasma catecholamines were measured in five normal male subjects before and after intravenous injection of saline or 10 mg metoclopramide. There were no consistent changes in hormone levels after saline injection. After metoclopramide, plasma aldosterone increased three‐fold to peak values at 20 min post‐injection. A significant increase in aldosterone was observed within 10 min during which period there was no significant change in plasma ACTH, plasma renin activity All or K. Plasma levels of cortisol, noradrenaline, adrenaline and dopamine showed no significant changes after injection of metoclopramide which induced a ten‐fold rise in plasma prolactin. These results provide direct evidence that factors other than the plasma concentration of ACTH, All and K—or fluctuations in plasma catecholamines—are likely to be responsible for the acute increase in plasma aldosterone after metoclopramide injection in n

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00129.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYSynthetic GH‐RH 1–44 administered as an intravenous bolus (1 μg/kg) evoked a marked hGH rise (>20 ng/ml) in three children with constitutional short stature and in two of eight children diagnosed as having hGH deficiency by insulin hypoglycaemia and/or clonidine tests. As judged by the intensity of the hGH response to the dose employed and the peak time, GH‐RH 1–44 may be as potent as GH‐RH 1–40 in children. It is concluded that GH‐RH is an important addition to the endocrine armamentarium, providing the means for differentiation between hypothalamic and pituiary hGH deficiency in a simple test which is devoid o

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00130.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYTrilostane is a competitive inhibitor of 3β‐hydroxysteroid dehydrogenase activityin vitroand an orally active inhibitor of steroidogenesisin vivo.A cytochemical section bioassay for this drug (4α, 5‐epoxy‐17β‐hydroxy‐3‐oxo‐5α‐androstane‐2α‐carbonitrile) in human plasma has been developed. The assay is based upon the inhibition of 3β‐hydroxysteroid dehydrogenase (3β‐HSD) activity in the corpus luteum of unfixed tissue sections (6 μm) of the mature dioestrous rat ovary. Trilostane is extracted from plasma by a simple chloroform procedure. The stanuard curve (0·15–2·5 μmol/I pure trilostane) exhibits a four‐fold change in 3β‐HSD activity and is constructed in the presence of extract from control plasma pools. The detection limit of the plasma assay is 2μmol/I trilostane after allowing for dilution effects and recovery losses. This level gives a significantly different response from the zero quality control (P<0·05) and has an inter‐assay coefficient of variation of2 μmol/1. Intra‐ and inter‐assay coefficients of variation using both plasma quality controls and unknown samples are 4% (n= 15) and 13·9% (n= 27) respectively. Recovery is 80·9% (n= 13) and 79·10% (n= 10) for plasma quality controls containing 12 and 4·8 μmol/1 trilostane respectively. Dilutions (up to 1:5) of plasma extracts are parallel to the standard curve and the assay throughput is approximately 16 samples/week technician. Testosterone, oestradiol, oestriol, dehydroepiandros‐terone (DHEA), DHEA‐sulphate, progesterone, cortisol, androstenedione and dexamethasone (all at 1 μmol/1) were without effect on the 3β‐HSD assay. It is concluded that t

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00131.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYSecretion of pancreatic polypeptide (PP) is regulated mainly by cholinergic mechanisms and we have studied this in patients with chronic renal failure (CRF). Basal serum PP concentrations in 25 patients with CRF (401 ± 80; 116–2100 pmol/1; mean ± SEM and range) were significantly higher than in 65 normal subjects (33 ± 2; 21–120 pmol/1,P<0·001). Ingestion of a standard test meal induced significantly larger increases in serum PP in 11 patients with CRF (304 ± 45; 155–640 pmol/1) than in 11 normal subjects (140 ± 33; 51–440 pmol/1,P<0·005). Insulin‐hypoglycaemia (0·1 U/kg i.v.) provoked similar increases in serum PP in five patients with CRF (404 ± 79; 170–665 pmol/1) as in five normal subjects (449 ± 92; 180–706 pmol/1). Administration of atropine (1 mg i.v.) did not normalize the elevated basal serum PP concentrations in five patients with CRF. On the other hand, administration of the same dose of atropine 60 min after ingestion of food decreased postprandial serum PP levels to basal values within one hour both in five patients with CRF and in six normal subjects. Sephadex G‐50 column chromatography of basal, postprandial and post‐atro‐pine sera from three patients with CRF revealed at least three different molecular forms. The PP peak coeluting with the 4200 molecular weight human PP standard comprised more than half of total PP immunoreactivity and was the only peak to be influenced by feeding or atropine. We conclude that in patients with CRF, PP secretion stimulated by cholinergic mechanisms is normal. In such patients post‐prandially released PP is dependent mainly upon cholinergic mechanisms, whereas the elevated basal serum PP concentration i

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00132.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYA simple, accurate and precise dispersed cell bioassay suitable for the assay of ACTH levels>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<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 13%. The sample throughput was 30 plasma sample

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00133.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYThe immunoreactivity of an extracted pancreatic human proinsulin standard in an indirect immunoradiometric assay was found to be at least one hundred times higher than that of biosynthetic human proinsulin. Limited tryptic digestion of the biosynthetic proinsulin increased its immunoreactivity in the assay and this was attributed to the production of partially cleaved proinsulin molecules which still retained the C‐peptide moeity. This inference was confirmed by the finding that pure samples of 65/A1 and 32/33 split proinsulins reacted in the assay very similarly to the pancreatic proinsulin standard. The implications of these results are that the immunoassays of proinsulin using antisera to C‐peptide may recognise the intact proinsulin molecule very poorly, if at all, and that the ‘proinsulin’ measured by such assays of human serum may be largely if not entirely intermediates of proinsulin c

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00134.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYAnabolic steroids have widespread metabolic effects but, to date, their proven clinical indications have been limited. Recently the 17 α‐alkylated steroid, stanozolol, has been shown to be of value in a variety of commonly occurring vascular diseases. Its endocrine effects have received little attention and we have investigated the effect of administering a 14 d course of stanozolol (10 mg orally per day) on a variety of important hormonal pathways in nine healthy male subjects. Significant changes occurred as follows: a 55% reduction in serum testosterone levels was noted and was accompanied by reductions in ‘derived’ free testosterone, sex hormone binding globulin and LH levels; total T4 and T3 levels fell in association with a decrease in thyroxine binding globulin, but no alteration was detected in TSH or free T4 levels. Changes in vitamin D status, with falls in 25‐hydroxycholecalciferol and vitamin D binding globulin were also observed. These effects were reversible on stopping treatment. Stanozolol therapy therefore leads to a number of hormonal changes, probably by an action at both pituitary and hepati

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00135.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYA kindred is described, six members of which fulfilled criteria for the syndrome of familial hypocalciuric hypercalcaemia (FHH). The majority of these individuals were asymptomatic: their hypercalcaemia was revealed by biochemical screening after parathyroid surgery had failed to diminish the elevated serum calcium concentration of the index case. In contrast to those members of the family diagnosed as adults, the daughter subsequently born to the index case included in her expression of FHH clinical features of severe neonatal primary hyperparathyroidism. Four hyperplastic parathyroid glands were excised, and following surgical intervention the baby improved clinically and accelerated the healing of her skeletal lesions. Her case suggests that an association does exist between FHH and neonatal primary hyperparathyroidism. Of the ten individuals at risk, inheritance of hypocalciuric hypercalcaemia was paralleled in eight cases by inheritance of the HLA haplotype All BW55 CW3 DR4. Such possible linkage has not previously been reported.

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00136.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYThe thyrotrophin (TSH) responses to thyrotrophin releasing hormone (TRH) in 16 oophorectomised postmenopausal women on long term treatment with mestranol 24 μg daily were compared to those in 16 oophorectomised postmenopausal women on placebo treatment. No significant difference between the groups was found in either basal TSH levels or the TSH response to TRH. It is therefore unlikely that the difference in TSH response to TRH between men and women of reproductive age is due to a direct stimulatory effect of oestrogen in women

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00137.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SUMMARYWe have developed a sensitive and selective radioimmunoassay for 24, 25‐dihydroxycholecalciferol (24,25(OH)2D3). Antisera with a high titre and affinity to 24, 25(OH)2D3were raised in rabbits immunized with a protein conjugate of the 3‐hemisuccinate derivative of 24, 25(OH)2D3. Serum samples were extracted by methanol/dichloromethane and the lipid extracts purified on Sephadex LH 20 and chromatographed by single step HPLC on a straight phase silica column. The radioimmunoassay is capable of measuring 24, 25(OH)2D3in the ‘24, 25(OH)2D complex’ isolated by HPLC and containing the comigrating metabolites: 24, 25(OH)2D3, 24, 25(OH)2D2, 25(OH)D3‐26, 23 lactone and 25, 26(OH)2D2. The detection limit of 2 pg/assay tube is a marked improvement, compared to the competitive protein binding assay using rachitic rat serum. Measured by the radioimmunoassay 24, 25(OH)2D3ranged from 0·05 to 1·96 ng/ml with a mean of 0·85 ng/ml in 34 healthy adults. For comparison 24, 25(OH)2D, measured simultaneously by competitive protein binding with rachitic rat serum, ranged from 0·1 to 4·0 ng/ml with a mean

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1984.tb00138.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY