摘要:

SUMMARYMelatonin, free and total cortisol, insulin, C‐peptide and glucose‐dependent insulin‐releasing peptide (GIP) were measured in the plasma of twelve normal volunteers (eight women and four men), at hourly intervals for 24 h following a meal and subsequent fasting. One volunteer was excluded from calculations due to a possible effect of stress on melatonin secretion. Melatonin and cortisol showed the normal 24‐h variation with peak values at 0200–0500 h, and 0900 h respectively. Following post‐prandial stimulation, gut hormones remained basal throughout the sampling period. No significant relationship was found between 24‐h melatonin secretion and basal, or stimulated gut hormone secretion. Melatonin secretion did relate significantly to body weight, suggesting that data concerning pineal effects in endocrine physiology and pathology, and effective disease, should be reviewed in the light of these

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1982.tb03151.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYBecause histidyl‐proline diketopiperazine (HPD), a metabolite of TRH, has been shown to suppress prolactin (PRL) release by rat pituitary tumour cells, human pituitary tumour cells were exposed to this compound. Monolayer cell cultures were initiated from pituitary tissue removed by transsphenoidal surgery from two patients with prolactin‐secreting microadenomas. Tumour fragments were mechanically dispersed; cells were seeded into multiwell plates and incubated in Ham's F‐10 medium enriched with fetal calf serum (20%). HPD (7±5 ng/ml) suppressed PRL release by both tumour cell cultures. Theophylline reversed the inhibition of PRL release induced by HPD. The data raise the possibility that HPD may act as an endogenous prolactin‐inhibiting facto

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1982.tb03152.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

SUMMARYA convenient, sensitive radioimmunoassay of free thyroxine in serum dialysates is described. The method utilizes a solid phase separation system (pre‐formed double antibody) and a relatively short incubation period (220 min) with a staggered addition of tracer. Blanks were low and consistent. The normal range for non‐pregnant euthyroid samples (n= 59) was 11–23 pmol/1. Third trimester pregnancy samples were mostly within the normal range but at the lower end. Patients on T4 replacement showed a much wider variation in free T4 levels with many samples in the hyperthyroid region. Some hypothyroid samples had undetectable free T4 levels and hyperthyroid samples were frequently greater than 80 p

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1982.tb03153.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY