ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01726.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01727.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYGH mRNA expression and GH release by Individual cells derived from four GH‐secreting pituitary adenomas were studied by in‐situ hybridization and the reverse haemolytic plaque assay, respectively. In addition the percentage of PRL mRNA‐containing cells was determined in these cell suspensions. The percentages of GH mRNA‐containing cells varied between 52 and 89 while the percentages of GH plaque forming cells varied between 25 and 77. Frequency distributions of GH mRNA levels in individual cells and of individual GH plaque areas showed a majority of the cells having low GH mRNA levels and secreting low amounts of GH respectively, while there is a low proportion of cells expressing high GH mRNA levels and forming large GH plaques. There was a significant correlation between the GH mRNA levels and the GH plaque areas of individual cells from the four adenomas (P>0.001). The percentages of PRL mRNA‐containing cells in the four different adenomas amounted to>1, 5, 2 and 18. Cultured cells from the adenomas consisting of 5 and 18|X% PRL mRNA‐containing cells also contained and released measurable amounts of PRL. Our data show that Individual cells from GH‐secreting pituitary adenomas are heterogeneous with respect to GH mRNA expression, a small proportion of the cells expressing a high amount of GH mRNA. The heterogeneity in GH mRNA expression is correlated with the heterogeneity In GH release. These observations suggest that a considerable part of GH secreted from a GH‐secreting pituitary adenoma is produced by a minority of the GH‐secreting tumour cell population. This might be a basis for the disappointing degree of tumour shrinkage which is observed in most acromegalic patients treated with the somatostatin ana

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01728.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYWe have studied the serum growth hormone (GH) response to two consecutive doses of growth hormone releasing hormone (GHRH) (50, 100, 200 μg) given 1, 2 or 3 h apart in seven adult males. The serum GH profile was analysed by deconvolution incorporating a variable half‐life for OH. All three doses of GHRH stimulated maximal GH secretion: 50 μg, 146.0 mU/min (SEM 24.0); 100 μg, 128.1 mU/min (SEM 14.3); 200 μg, 134.1 mU/min (SEM 20.5) (one‐way ANOVA, P = NS). The magnitude of the second secretory burst after the second dose of GHRH was less than that Induced by the first injection of GHRH, particularly when doses of 200 μg were used. Factors influencing the response to the second dose were the GH secretory status at the point that the stimulus was applied and the time interval between administration of the first and second doses. These studies demonstrate that the pituitary gland is capable of responding to two consecutive doses of GHRH although the second response is always less than the first. The data demonstrate the importance of using methods of assessing GH secretion and not relying simply on measured serum GH concentratio

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01729.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYCirculating levels of immunoreactive inhibin (ir‐inhibin) and its disappearance after delivery of the placenta were determined in seven pregnant women at term. Serum cestradiol (E2) and progesterone (P4) levels were measured simultaneously and served as comparisons. Fetal contributions of ir‐inhibin were asessed by determining concentrations in the umbilical artery (UA) and vein (UV). Relative changes in circulating levels of ir‐inhibin, E2, and P4 were compared to levels found in nonpregnant women during the early follicular phase (EFP) and mid‐luteal phase (MLP) of the normal menstrual cycle. In pregnant women, ir‐inhibin levels at delivery were 15‐ and 3‐fold higher than EFP and MLP values respectively. The disappearance of all three hormones after removal of the placenta followed a bi‐exponential curve with an initial, rapid component and a second, slower component. There was a highly signifiant positive correlation between the disappearance curves of all three placental hormones (r = 0–97, P>013001). Concentrations of ir‐inhibin in the cord blood were about half that in maternal serum and without significant difference between

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01730.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYBromocriptine is currently and successfully used for the treatment of pituitary prolactinomas. However, bromocriptine appears unable to normalize plasma prolactin levels in about 10|X% and to reduce tumour size in one‐third of cases. The lack of normalization of plasma prolactin levels in spite of a daily dose of bromocriptine equal to or higher than 15 mg suggests a bromocriptine resistance. We compared the long‐term effects of bromocriptine and CV 205–502 (a non‐ergot derivative D2dopamine agonist) on plasma prolactin levels and tumour size in seven bromocriptine‐resistant prolactinomas. Bromocriptine reduced significantly (P>0.001) plasma prolactln levels (from 2307 |Mp 518 to 568 |Mp 279 μg/I) (conversion to SI units: 1 μg/I = 20 mU/I). Visual field defects observed in five patients Improved in four. However, CT scan analysis showed a decrease in tumour size in only three patients. Except for transient and minor side‐effects at the beginning of the treatment, CV 205–502 was well tolerated In five of seven patients. In the remaining two patients nausea and vertigo occurred with high dosages of CV 205–502 and it was necessary to reduce the daily dose. CV 205–502 lowered plasma prolactin to levels similar to those obtained after bromocriptine therapy in four cases. In the three remaining patients, CV 205–502 was more potent than bromocriptine as demonstrated by the further 90|X% reduction in plasma levels obtained in one case and by the normalization of plasma prolactin levels in the two other cases. One woman became pregnant during CV 205–502 treatment. However, no further change in visual disturbance or in tumour size was observed during the treatment with CV 205–502. These results show that CV 205–502 appears to be more potent than bromocriptine in reducing plasma prolactin levels in some bromocriptine‐resistant prolactinomas and suggest that different mechanisms may be

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01731.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYA 60‐year‐old woman was evaluated for persistently elevated serum testosterone concentrations after bilateral ovariectomy. Her serum cortisol, androstenedione, dehydroepiandrosterone sulphate and 17‐hydroxyprogesterone levels were normal, and decreased after dexamethasone administration. Those of testosterone (17.8–18.4 nmol/l) were remarkably high (normal range 0.7–2.8 nmol/l), were not suppressed by dexamethasone, but clearly increased after hCG administration (up to 128 nmol/l). Computed tomography revealed an adenoma in the right adrenal gland and adrenal scintigraphy under dexamethasone suppression visualized this adenoma. A right adrenalectomy was performed. (1) The tumour was histologically and ultrastructurally adrenocortical adenoma of zona reticularis cell type. (2) The adenoma tissue contained hCG receptors (198 fmol/g). (3) During tissue culture both ACTH and hCG were capable of maintaining its testosterone production, which was attenuated with time without stimulation. (4) The adenoma tissue did not elaborate 21‐hydroxylated steroids In contrast to normal adrenal tissue. Thus the aberrant endocrine behaviour of this gonadotrophin‐responsive testosterone‐secreting adenoma of adrenal zona reticularis cell origin can be explained by ectopic functional hCG receptors and the lack of 21‐hy

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01732.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYPrevention of postmenopausal osteoporosis is now possible with current therapy, if initiated soon after the menopause and continued for at least 10 years. Simple ways of detecting those at risk of subsequent osteoporosis are urgently needed. This study investigated the hypothesis that certain serum sex hormones could predict bone mineral content (BMC) as measured by dual photon densitometry, soon after the menopause. The subjects included 136 healthy white females within 30 months of their last menstrual period with a mean age of 52 years. Of the sex hormones, the adrenal androgen dehydroeplan‐drosterone sulphate (DHEAS) correlated best with spinal BMC, a relationship which was significant using multiple regression (P = 0.02), although the correlation was weak (r =+0.19). A direct physiological role for DHEAS has yet to be found, despite being present in large quantities in serum, although it may act as a marker for other processes. No association was seen between testosterone, sex hormone binding globulin, oestradiol, oestrone and oestrone sulphate and spinal BMC. No significant correlations with any hormones were seen with femoral BMC. The data suggest that serum sex hormones are not useful markers of current bone mineral status soon after the menopause, although further work is needed to explore the relationship with DHE

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01733.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYTwo patients with severe ovarian hyperstimulation syndrome are described. Increased plasma concentrations of immunoradlometrically determined total renin are shown, together with greatly increased plasma levels of active renin and aldosterone. These very high values for total renin, renin activity and aldosterone were not suppressed when extracellular compartments were greatly expanded; the values subsequently declined to normal levels, despite the use of diuretics. This suggested that the renin was of non‐renal origin since its production was apparently unaffected by influences which control juxtaglomerular secretion. The high concentrations of the rennin—angiotensin—aldosterone system suggest that it contributes to the genesis of the ovarian hyperstimulation sy

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01734.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SUMMARYTo examine the relationship between corticotrophin releasing hormone (CRH), arginine vasopressin (AVP) and oxytocin (OXT) we have studied the responses of adenohypophyseal and neurohypophyseal hormones to CRH in eight patients (age 26–64 years, six female) with suspected pituitary‐dependent Cushing's syndrome during bilateral, simultaneous inferior petrosal sinus catheterization. Blood samples were taken from both petrosal sinuses and a peripheral vein before, and at 5‐min intervals for 15 min after, an intravenous injection of 100 μg human CRH1–41. CRH increased sinus AVP concentrations in all eight patients and OXT concentrations in four of five patients studied. Although AVP concentrations often increased in both sinuses, the side of maximal AVP rise was termed sidemax‐AVP. CRH did not affect peripheral or petrosal sinus mean concentrations of LH, FSH, GH or TSH. While there was no change in mean peripheral concentrations of AVP, OXT, ACTH, ACTH precursors or prolactin after CRH, sinus concentrations of OXT, ACTH and prolactin on sidemax‐AVPwere markedly elevated over contralateral values. CRH did not increase mean sinus concentrations of ACTH precursors. In seven patients with either no radiological abnormality of the pituitary fossa or a small adenoma the mean ACTH precursor/ACTH ratio in blood sampled from all sites was 2.1 |Mp 0.16 (mean |Mp SEM, n = 50). In a patient with a large, locally invasive tumour the mean ACTH precursor/ACTH molar ratio was 32.1 |Mp 1.3 (n = 12; P>0.001), suggesting that alterations in this molar ratio may reflect the biological properties of the tumour. The source of CRH‐stimulatable AVP and OXT remains uncertain. While it is recognized that the data were accumulated in patients with pathology of the hypothalamo—hypophyseal—adrenal axis, these observations suggest a novel relationship between AVP, OXT and CRH in the regulation of ACTH secretion in man. We suggest that the relation between plasma AVP and corticosteroids seen in clinical hypoadrenal states could be explained by chronic stimulation of AV

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1991.tb01735.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY