ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb03333.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYCortisol, androstenedione, testosterone, dehydroepiandrosterone sulphate (DHAS) and free dehydroepiandrosterone (DHA) were measured in plasma of ten women affected by amenorrhoea with hyperprolactinaemia and eleven women affected by secondary hypothalamic amenorrhoea; twelve normal women at the second day of the menstrual cycle were used as controls. All subjects were hospitalized and 17‐ketosteroids, 170H‐corticosteroids and total dehydroepiandrosterone were also measured in urine.Plasma DHAS was increased in all subjects affected by amenorrhoea with hyperprolactinaemia, while plasma DHA and urinary DHA were significantly increased in this group in comparison to other groups. Plasma cortisol, androstenedione and testosterone and urinary 17‐oxosteroids and 170H‐corticosteroids were not significantly different in the three groups.In subjects affected by amenorrhoea with hyperprolactinaemia treated with bromocriptine a clear decrease of DHAS correlating with a decrease of plasma prolactin was observed.Since in women DHAS seems to be almost exclusively secreted by the adrenal gland and most of the circulating DHA is derived from adrenal secretion, these data suggest that human prolactin can stimulate DHAS production by the adrenal

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01990.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYHypothalamic regulation of prolactin secretion in animals (mammals) and man appears to be similar, and no significant differences have yet been demonstrated. The hypothalamus contains neurotransmitters and polypeptides that can either inhibit or stimulate prolactin release, although the predominant influence under basal conditions is to inhibit prolactin release. Thus pituitary stalk section or placement of lesions in the basal tuberal region of the hypothalamus results in increased prolactin release and sometimes in initiation of lactation. Among agents in the hypothalamus that can inhibit prolactin release, the most important appear to be an as yet unidentified polypeptide prolactin release inhibiting factor (PIF) and dopamine. There is some evidence that dopamine may account for most, if not all, of the prolactin release inhibiting activity of the hypothalamus. Agents that increase dopamine activity, i.e. L‐dopa, monoamine oxidase inhibitors, etc., depress prolactin release. Acetylcholine also can inhibit prolactin release, but it appears to act via the catecholamines. Of the agents in the hypothalamus that stimulate prolactin release, the most important appear to be an as yet uncharacterized polypeptide prolactin releasing factor (PRF), thyrotropin releasing hormone (TRH) and serotonin. TRH is as effective in releasing prolactin as in releasing TSH, but under most physiological states, TSH and prolactin release do not occur together. Serotonin and its precursors, tryptophan and 5‐hydroxytryptophan, are powerful releasors of prolactin and have been shown to be involved in some physiological states in which prolactin is released, i.e. during suckling, stress, etc. Other agents in the hypothalamus that can stimulate prolactin release include GABA and some prostaglandins, but these have not yet been shown to be involved in physiological control of prolactin secretion. Exteroceptive stimuli that alter prolactin release act through the CNS and hypothalamus, but some hormones and drugs also can act directly on the pituitary to promote or depress prolactin rele

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb03334.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYThe effect of synthetic LHRH on plasma concentrations of LH, FSH, testosterone and testosterone response to i.v. HCG was studied in fifteen normal men and in fifteen men with impotence.The mean basal concentrations of LH, FSH and testosterone in the men with impotence were not significantly different from those of the normal group. A normal response of gonadotrophins and testosterone was also observed. It is concluded that a normal pituitary sensitivity to synthetic LHRH and a normal response to endogenous and exogenous gonadotrophins exist in this particular disorder.

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01991.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYThe hypoglycaemic action of somatostatin was investigated in fasted anaesthetized dogs. An isotopic turnover technique with radioactive D‐[2‐3H] glucose tracer was used to measure the rats of hepatic production and peripheral utilization of glucose before, during, and after a 60 min infusion of 150 μg somatostatin. Plasma concentrations of insulin, glucagon, growth hormone, cortisol and free fatty acids were also measured.Somatostatin infusion caused a fall of plasma glucose demonstrable within 10 min. After 60 min plasma glucose had fallen to 75% of the pre‐infusion concentration. Simultaneously the specific activity of the D‐[2‐3H] glucose increased and calculation of the rates of production and utilization of glucose over 10 min intervals indicated that the mean hepatic production rate of glucose fell to 59% of the pre‐infusion rate while the rate of peripheral utilization of glucose fell to 83% of the pre‐infusion rate. These results show that the hypoglycaemic action of intravenous somatostatin depends exclusively upon the inhibition of hepatic glucose production. This effect may have been partly due to a fall of plasma glucagon concentration and occurred despite a fall of plasma insulin to less

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01992.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYGrowth hormone and prolactin are secreted episodically in man and experimental animals. To investigate physiologic mechanisms of GH and PRL secretion, a series of experiments were performed in individual, unanaesthetized male and female rats.GH secretion in the male rat is characterized by intermittent surges that occur approximately every 3 h and are entrained to the light‐dark cycle. Peaks reach 200‐400 ng/ml and troughs are unmeasurable. PRL is secreted in more frequent episodes with a pattern distinct from GH.In the female rat, GH surges occur more frequently‐approximately once each hour. PRL levels are low (<15 ng/ml) except on the afternoon of pro‐oestrous when they surge to levels of 100‐300 ng/ml. Prolactin rises 4‐6 h before delivery. Levels decline rapidly at the onset of parturition and surge with each episode of suckling in the post‐partum period. Growth hormone and corticosterone rise during delivery and remain elevated for several hours after delivery. Reinstitution of suckling after removal of pups causes an immediate rise in PRL and GH. The PRL response is sustained for 3‐4 h, whereas the GH response is brief with return to baseline within 1 h. The time courses of the two responses are clearly independent.Stress in the male rat causes a rapid rise in PRL and suppression in GH. The PRL surge to stress is brief with return to baseline by 1 h. GH pulses are suppressed for up to 5 h after stress.These studies indicate that separate neuroendocrine control mechanisms exist for regulation of the episodic release of GH and

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb03335.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYFrom a sibship of three sisters having congenital goitre and normal hearing, two had impairment of organification of iodide. S1(4 years old) had goitre since birth, euthyroidism, and a negative perchlorate test. S2(15 years old) and S3(13 years old) were hypothyroid, and had radioiodide discharge after potassium perchlorate administration of 19.8% and 26.1%, respectively. Thyroid tissue was obtained at thyroidectomy. Peroxidase activity, in the thyroidal subcellular particles, was found to be qualitatively normal, but quantitatively increased. In the triiodide assay, the activity was: S16912 u, S22590 u, and S33844 u (normal values 900‐1700 u). In the tyrosine‐iodinase assay, the activities, expressed as nmoles of iodide incorporation per gram of tissue, were S11046, S2471, and S3547 (normal values 220‐410). The activity of the thyroidal NADPH‐cytochrome c reductase, an enzyme possible involved in hydrogen peroxide generation, was: S10.084, S20.047, and S30.055 (normal values 0.018 μEq/min/mg). No thyroglobulin was detected by analytical ultracentrifugation, polyacrylamide gel electrophoresis, or double immunodiffusion in agar of the supernatant fractions. In patient S3, whose gland was labelledin vivowith125I, 60% of the total radioactivity of the gland (pooled nodular and paranodular specimens) was in a particulate iodoprotein that was solubilized by trypsin, deoxycholate or digitonin. In the soluble fraction there were two iodoproteins: iodoalbumin, and a second iodoprotein similar to the solubilized particulate iodoprotein.It is postulated that absence of the normal thyroidal receptor protein might be in some cases a cause of iodine organificatio

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01993.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYMany of the factors altering corticosterone in the rat have similar effects on prolactin. Resting prolactin, like corticosterone, is higher in animals housed singly than in those multiply housed. Unlike corticosterone, gentling did not lower prolactin. An exquisite sensitivity to environmental stimuli which results in rapid elevations in prolactin levels has been indentified in the rat which is considerably greater than that for corticosterone. Like corticosterone, the pattern of prolactin stress responses varies according to time of day. This differential sensitivity may well account for the diurnal variation in prolactin reported by some investigators. The limbic system has an important influence on prolactin. Lesions of the septal region do not modify resting levels but alter the pattern of prolactin stress responses in ways which are only partly similar to the effects of such lesions on corticosterone.In rhesus monkeys, individual variation in resting prolactin levels was observed, similar to that seen in the human. Levels are stable over periods of up to 50 days and are characteristic of the individual animal. In response to the stress of electric shock or shaping to a bar press response, prolactin elevation occursonlyin animals with high resting levels, suggesting that a common mechanism is responsible for controlling both resting levels and magnitude of stress responses.

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb03336.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYA survey in a general practice in the North‐East of England in 1963 detected thyroglobulin antibodies in 16.2% of women and 4.3% of men. High titres of antibodies were found in 4.6% of women and 1.6% of men. Forty‐six subjects with thyroglobulin antibodies (from an original total of fifty‐two) were studied in 1972 and forty of these were studied further in 1975. These subjects were compared with a group of age‐ and sex‐matched controls from the original survey. Three of the subjects had developed overt hypothyroidism by 1975 and a raised serum thyroid‐stimulating hormone (TSH) concentration was found more frequently in euthyroid subjects previously found to be antibody positive. There was a striking difference in the antibody studies in that only 26% of the previously antibody positive subjects had thyroglobulin antibodies in 1972 and 30% in 1975. A raised serum TSH concentration was found to correlate with cytoplasmic antibodies and particularly with the combination of cytoplasmic and thyroglobulin

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01994.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb03337.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY