摘要:

SUMMARYDiurnal studies were performed on ten normal volunteers taking a normal sodium diet. Half‐hourly blood samples were taken throughout 25 h and assayed for plasma renin activity (PRA) and the plasma concentrations of noradrenaline, aldosterone and cortisol. Sleep was recorded polygraphically and scored by standard criteria. Circadian rhythms were demonstrated for plasma cortisol, aldosterone and noradrenaline concentrations, but not for plasma renin activity. The nadir of the rhythm for the noradrenaline concentration appeared to be related to sleep itself rather than to any chronological index. Only PRA was effected by the stage of sleep, falling sharply during periods of REM sleep. Plasma cortisol and aldosterone concentrations showed a positive correlation over the 24 h. There was, however, no correlation between PRA and plasma aldosterone concentrations, except when the subjects arose after their night's recumbency. Plasma noradrenaline concentration did not correlate with the concentration of any of the other hormones measure

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00190.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYIn forty‐two patients with chronic renal failure (CRF), serum concentrations of 25‐hydroxy‐cholecalciferol (25‐OHCC), 24,25‐dihydroxy‐cholecalciferol (24,25‐OH2CC) and 1,25‐dihydroxy‐cholecalciferol (1,25‐OH2CC) were measured before and during intermittent haemodialysis (IHD) and in a few cases also after renal transplantation. 25‐OHCC and 24,25‐OH2CC were measured by means of a competitive protein binding assay after Sephadex LH 20 chromatography and 1,25‐OH2CC by means of a radioimmunoassay after Sephadex LH 20 and high pressure liquid chromatography (HPLC). In our patients serum values for 25‐OHCC and 24,25‐OH2CC showed a seasonal fluctuation as in normal individuals. The concentrations in the serum of 24,25‐OH2CC and 1,25‐OH2CC showed a positive correlation with renal function. With regard to 24,25‐OH2CC this correlation was only found for the 24,25‐OH2CC: 25‐OHCC ratio which was used to eliminate the seasonal fluctuation. For both dihydroxylated metabolites subnormal concentrations were found when the creatinine clearance was 40–50 ml/min and lower. It appears that the decrease of the plasma level of these metabolites of Vitamin D preceeds (or is concomitant with) the changes in the serum values of calcium (Ca), phosphorus (P) and parathyroid hormone (PTH) and the diminution of the intestinal absorption of Ca. These findings indicate that patients with CRF should be treated at an early stage of the disease with 1α‐hydroxy‐derivatives of Vitamin D in order to prevent the development of, or to induce the he

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00191.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYDaily measurements of plasma FSH, LH, prolactin, testosterone, 17β‐oestradiol and sex hormone binding globulin (SHBG) activity were made in eight healthy, normal men during treatment with oral ethinyloestradiol (EE2) in a dose of 30 μg/day for 5 days following a 5‐day control period. No significant changes in plasma levels of FSH and prolactin during oestrogen treatment occurred. In contrast, plasma concentrations of both LH and testosterone showed a biphasic pattern. Following an initial suppression during the first 3 days of oestrogen treatment both LH and testosterone increased again to baseline values despite continuation of oestrogen administration. The secondary rise of both hormones was associated with (and probably resulted from) a nearly 100% increase in the plasma concentration of SHBG binding activity, and hence reduction of free testosterone index (FTI). Unlike testosterone, plasma 17β‐oestradiol during EE2administration did not show a biphasic pattern, but a progressive decline that was positively correlated with the fall in FTI. The rapidity of onset and magnitude of the observed rise in SHBG levels emphasizes the need for measurement of this binding protein (or the free testosterone fraction) in studies on feedback regulation of gonadotrophins employing exogenous EE2in human males. The observed increase of SHBG to supraphysiological values suggests that currently employed EE2doses in such studies may be less ‘physiologic’ than is o

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00192.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThe excretion of follicle stimulating hormone (FSH), luteinizing hormone (LH), oestrogens and pregnanediol was measured in weekly urine samples collected for 14–87 weeks (median, 43 weeks) from thirty‐one perimenopausal women aged 36–55 years (median, 50 years). The results were compared with those found in twenty‐two postmenopausal women aged 55·4 ± 5·4 years (mean ± SD), and in twenty premenopausal women aged 44·4 ± 3·4 years with regular, ovulatory, menstrual cycles. Women classed as perimenopausal had a recent history of irregular menstrual cycles following regular cyclicity. The hormone patterns observed in the perimenopausal women varied widely, both between individuals and from time to time in the same individual. They ranged from ovulatory cycles with low premenopausal levels of FSH, to transient episodes indistinguishable from those found in postmenopausal women with high levels of FSH and LH. Between these extremes were patterns rarely seen at other times in reproductive life: namely, (1) in fourteen women on thirty‐two occasions lasting 2–9 weeks, postmenopausal levels of FSH and LH occurred in association with high oestrogen levels; (2) in eighteen women on thirty occasions lasting 2–8 weeks, there was an elevation of LH (but not FSH) into the postmenopausal range; (3) in thirteen women on twenty‐six occasions lasting 1–2 weeks, there was an elevation of FSH (but not LH) into the postmenopausal range. These patterns were not seen in any of the premenopausal women. Typically, the approach of the menopause was marked by an increased incidence of high postmenopausal levels of FSH and LH. Ovulatory cycles were observed at all stages in the perimenopause, and occurred within 16 weeks of the last menstrual period in seven of the thirteen women who became postmenopausal during the study. It is concluded that the appearance of high levels of FSH and LH is characteristic of the perimenopause and often precedes the sustained loss of sex hormone secretion by the ageing ovary. Postmenopausal biochemical parameters are no guarantee of

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00193.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThe effect of oestradiol benzoate on serum gonadotrophin concentrations before and after LHRH administration was studied in lactating and non‐lactating women at 3 and 6 weeks post‐partum. Except in the non‐lactating women at 6 weeks, basal serum FSH concentrations were suppressed by oestrogen. There were no significant changes in basal concentrations of LH after oestrogen in the lactating women in either the 3‐ or 6‐week studies. Individual increases in the basal LH concentrations in two out of six non‐lactating subjects in the 6‐week study occurred but overall there were no significant changes.In the 6‐week study amplification of the LH response to LHRH was found in both groups, the effect being significantly greater in the non‐lactating women. Overall FSH responses were also significantly different in the two groups, being suppression in those lactating and amplification in those not lactating. The LH/FSH ratios following LHRH administration in the 6‐week non‐lactating study were similar to those seen in the early follicular phase in regularly menstruating subjects. The basal ratios in the lactating subjects were, however, significantly less than those seen in the non‐lactating subjects both at 3 and 6 weeks. This difference was associated with the relative enhancement of LH release in non‐lactating subjects and enhancement of FSH release in those lactating.Taken together the results indicate the presence of an intact negative feedback of oestrogen on gonadotrophin release in both groups being enhanced at 6 weeks post‐partum in the lactating subjects; also in the lactating subjects at 6 weeks there was less amplification by oestrogen of the responsiveness of the anterior pituitary to LHRH. At 6 weeks, however, in the non‐lactating group these responses were similar to those seen in normal regularly menstruating subjects. These dynamic endocrine studies suggest a possible hypothalamic‐ pituitary mechanism which may help to explain the delayed return of ovul

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00194.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThis study examines the degree to which erythrocyte insulin receptors might be used instead of monocyte insulin receptors to assess overall insulin receptor status. Red blood cells from eight normal subjects were fractionated into older and younger populations by high speed centrifugation. Fractionated red cells (3·5 ± 109/ml) were incubated with 0·14 ng/ml of ‘monoiodo’125I‐insulin for 2·5 h at 15°C. The high reticulocyte fractions (mean 2·1% reticulocytes) had greater insulin binding than the low reticulocyte fractions (mean 0·6%), −9·0% compared with 6·0% specific binding, respectively. The difference (P>0·05) appeared to be predominantly due to a greater number of high affinity sites per cell in the high reticulocyte fractions. Culture of high and low reticulocyte fractions, from both normal subjects and patients with high reticulocyte counts,in vitrofor 2·5 days at 37°C, markedly reduced reticulocyte count and insulin binding of the high reticulocyte fractions, but produced little change in the low reticulocyte fractions. It appeared the reticulocytes had a ten‐ to twenty‐fold increase in binding sites compared with erythrocytes.There is little degradation of insulin by intact erythrocytes or reticulocytes at 37°C, with a dissociation between insulin binding and insulin degradation. The large degradative capacity of haemolysed red cells implies that insulin receptor assays would be invalid in the presence of haemolysis.Monocyte and erythrocyte receptors were compared in the same blood samples from overnight fasted subjects, with a correlation between insulin binding (r = 0·62). The inexact correlation may be partly due to the non‐homogeneous insulin binding of red cells, but correction for differences between reticulocyte content of the assayed red cells only increased the correlation to r = 0.67. Whilst the non‐homogeneity of red cells means that erythrocyte binding must be interpreted with caution, we cannot exclude similar non‐homo

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00195.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThe ‘basal’ plasma glucose, defined as the stable overnight concentration, has been assessed as an index of diabetes control by comparison with plasma glucose measurements during 24‐h profiles in diet‐treated maturity‐onset diabetic patients and normal subjects. The basal plasma glucose correlated with the total (r = 0·98) and incremental (r = 0·86) glucose areas, as well as the 24‐h M value (r = 0·90). In mild diabetes the basal value was more abnormal than the incremental glucose area after meals, since 3 h after meals ‘reactive hypoglycaemia’ lowered the plasma glucose to less than the basal value. Thus diabetics with a raised basal plasma glucose up to 8 mmol/1 can have a normal 3‐h post‐prandial value. A raised basal plasma glucose provides similar diagnostic information to conventional oral glucose tolerance tests and provides an apposite measure of diabetes control. Diabetics who come up to a clinic, or who exercise whilst fasting, have fasting plasma glucose and insulin concentrations slightly higher than their overnight ‘basal’ levels, whereas there is little change in normal subjects. This higher ‘stressed fasting’ plasma glucose needs to be taken into account when assessing fasting plasma glucose values.This work was presented in part at the 13th Annual Meeting of the European Diabetes Assoc

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00196.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYIn order to assess a possible influence of endogenous opioids upon gonadotrophin secretion in women, we examined the effects of i.v. administration of 10 mg naloxone, a specific opiate antagonist, in ten normal menstruating women, in thirteen women with amenorrhoea and/or hyperprolactinaemia and in two women with putative deficiency of gonadotrophin‐releasing hormone (GnRH). In thirteen subjects, a saline vehicle control study (randomized order of administration) was also performed. In the normal women, naloxone failed to elicit changes in serum gonadotrophin levels when administered during the early follicular phase of the menstrual cycle. However, significant increments of LH were observed from 30 to 165 min following naloxone administration during the late follicular phase. Similar LH responses occurred in the amenorrhoeic and hyperprolactinaemic women. There was a tendency towards a concomitant increment in FSH levels, which reached statistical significance variably from 60 to 105 min post‐naloxone. The LH response to naloxone in individual subjects showed a significant (P>0·01) quadratic (U‐shaped) relationship to the log basal oestradiol concentration. No response to naloxone was observed in the two patients with GnRH deficiency despite a brisk response to an exogenous GnRH bolus. Taken together, these data suggest that central nervous system inhibitory opioid pathways may be involved in the regulation of LH secretion in normal women and that excessive production of endogenous opioids may play a role in the pathophysiology of some amenorrhoeic cond

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00197.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYIn order to assess neonatal thyroid function in the endemic goitre areas of Greece, T4 and TSH have been measured. Previous studies had shown that in these endemic areas, adults had low T4 but normal TSH values, probably because of an increase in the serum T3 level. In this study, T4 and TSH were measured in dried blood spots from 259 neonates. The fifty‐four full‐term neonates from the Greek endemic villages had a lower T4 value (8·8 ± 0·66 μg/dl SE) but a higher TSH (15·37 ± 1·12 mu/l) than the seventy‐three full‐ term neonates from the non‐endemic villages (T4:10·0 ± 0·33 μg/dl, TSH: 11·93 ± 0·59 mu/l) or the ninety‐eight from Athens (T4:10·0 ± 0·33 μg/dl, TSH: 10·96 ± 0·64 mu/l). Premature neonates, both from Athens and from the endemic areas, have significantly lower T4 and significantly lower TSH values than the full‐term ones from the same areas, probably because of the immaturity of the pituitary‐thyroidal axis. It is concluded from these observations that (a) Neonates suffer more from the consequences of iodine deficiency than adults. The biochemical hypothyroidism reported here may be relevant to the delayed skeletal maturation previously reported from children of these same areas. This emphasizes the need for correcting even moderate iodine deficiency. (b) The occurrence of non‐toxic goitre with normal TSH levels in adults is best explained by assuming that increased TSH stimulation is necessary for goitre formation during neonatal life, but not for goitre maintainance during adulthood. (c) Newborn screening programmes in these areas should

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00198.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThyroid membrane preparations from six patients with active Graves’ disease were tested in an assay which detects the thyroid interactive immunoglobulins of Graves’ disease by their inhibition of binding of [125I]‐thyroid stimulating hormone (TSH). With all preparations inhibition of binding of125I‐TSH by excess TSH could be demonstrated (specific binding). The patients’ own immunoglobulins were assayed against their own thyroid membranes and against each other's under exactly comparable conditions. Inhibition of binding by IgGs from the patients varied between membrane preparations: with one preparation 5/6 IgGs were inhibitory but with another none were effective. Of the six patients, their own IgG inhibited binding of125I‐TSH to their own thyroid membrane preparation in only four instances, and when interaction did occur this did not reliably predict that the membrane preparation would interact with IgGs from other patients with Graves’ disease. The selection of a membrane preparation for this assay cannot be made solely on ability to specifically bind TSH but the measure of the specific interaction with a Graves’ IgG of proven potency must also be considered. Moreover, because of the variability between different membrane preparations, sequential clinical studies on individual patients, of the changes in concentration of Graves’ IgG, must be performed using the same selected thyroid membrane preparation.We infer from these observations that the membrane structure in the vicinity of the TSH binding site is an important determinant of the interaction of Graves’ IgGs with the TSH receptor, and that the configuration of this area is variable between individuals of the same species. The distinction between ‘human‐specific’ and ‘non‐species‐specific’ thyroid stimulating antibodies is therefore probably not valid. The observation that the patient's own IgG was not often the most potent IgG inhibitor of binding of TSH also suggests that the Graves’ IgG binding site is not identical or restricted to the TSH binding site; alt

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1981.tb00199.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY