Biomedical subjects

L Wide

Publications and source records attributed to L Wide.

At least 55 records · Page 3Linked to original sources

PubMed1994

Intact serum parathyroid hormone levels increase during running exercise in well-trained men.

The purpose of this study was to examine the influence of exercise on the serum concentrations of intact parathyroid hormone (PTH). Serum PTH and plasma lactate were measured in 15 well-trained men, 9 long-distance runners and 6 fire-fighters, during two running exercises. Test one consisted of 40-minute treadmill running with a step-wise increased load and test two consisted of 50-minute treadmill running with a constant velocity. When the load was step-wise increased, the PTH concentrations increased moderately at the slower running paces but reached a final value that was about 50% higher than the starting value. This rise occurred despite a concomitant increase of total serum calcium from 2.38 +/- 0.06 to 2.49 +/- 0.05 mmol/liter (P < 0.01). During the constant running exercise, the long-distance runners, but not the fire-fighters, displayed a significant increase in PTH concentrations although the rise in total serum calcium was similar in both groups. There was a weak correlation between the changes in PTH and lactate in both exercises. The findings demonstrate that both high and low intensity exercise enhance release of PTH in long-distance runners through a mechanism that does not involve serum calcium. This relationship might be of importance for bone mass in men performing long-distance training.

Adult↗

PubMed1994

17 beta-oestradiol counteracts the formation of the more acidic isoforms of follicle-stimulating hormone and luteinizing hormone after menopause.

OBJECTIVE: When the gonadotrophin levels increase at midcycle, more basic isoforms of FSH and LH appear in the circulation. However, when these gonadotrophins increase at menopause more acidic forms appear. The present study was done to see whether chronic 17 beta-oestradiol (E2) administration to post-menopausal women could counteract the formation of the more acidic isoforms after the menopause. DESIGN: Serum samples were obtained from 16 post-menopausal women, mean age 70 years (range 63-84 years), 46-169 days after the subcutaneous insertion of a 20-mg E2-implant. FSH, LH and E2 in the sera were measured with fluoroimmunoassays. The median charge and the degree of charge heterogeneity of the FSH and LH isoforms were determined for each serum by electrophoresis in 0.1% agarose suspension. Sera from an age-matched control group were analysed in parallel. RESULTS: The E2 levels in the E2-treated women were 230-570 pmol/l, within the range expected during the mid-luteal phase of the normal menstrual cycle. The mean serum FSH and LH levels were similar to normal follicular phase FSH and LH levels (8.6 and 20.8% respectively of the control group). It was estimated that individual serum specimens from both groups contained 20-30 different isoforms for both FSH and LH. The median charges of the isoforms of FSH and LH were more basic in all the E2-treated subjects than in their corresponding untreated controls. The mean median charge for FSH was close to the values for the follicular and luteal phases and that for LH close to that for the luteal phase. In some E2-treated women the isoforms were even more basic with a charge similar to that at the midcycle peak. The degree of charge heterogeneity for the E2-treated group was significantly (P < 0.001) larger than for the controls and similar to that during the normal menstrual cycle. CONCLUSION: Chronic E2 administration to post-menopausal women counteracted the formation of more acidic isoforms of both FSH and LH after the menopause.

Aged↗

PubMed1994

The independent effects of polycystic ovary syndrome and obesity on serum concentrations of gonadotrophins and sex steroids in premenopausal women.

OBJECTIVE: To investigate the basal levels of gonadotrophins and sex steroids, with special reference to the effects of obesity and body fat distribution, in premenopausal women, both those with polycystic ovary syndrome (PCOS) and those with normal ovaries and regular menstrual cycles. DESIGN: Cross-sectional study. The separate effects of obesity (and body fat distribution and fasting insulin levels) and PCOS on endocrine variables were evaluated by means of analysis of covariance. PATIENTS: Sixty-seven women with anovulatory menstrual cycles and polycystic ovaries according to ultrasonography and 59 women with normal ovaries and regular cycles, both groups covering a wide range of body mass index (BMI, PCOS, 17.6-37.4, mean 25.7 kg/m2; controls, 18.8-40.9, mean 25.1 kg/m2). MEASUREMENTS: Serum levels of gonadotrophins, sex steroid hormones, prolactin and GH obtained in the early follicular phase in the controls, fasting insulin levels, anthropometric measures (BMI, skinfolds, waist hip ratio). RESULTS: Mean serum concentrations of LH, androstenedione, testosterone, the free androgen index (FAI; all P < 0.0001) and DHEAS (P < 0.01) were higher, and serum FSH (P < 0.01) and serum SHBG levels lower (P < 0.0001), in the PCOS group than in the controls. Women with PCOS had a more pronounced upper body fat distribution and higher fasting insulin levels than the controls. Independent of PCOS, BMI was positively associated with serum levels of FSH (P < 0.001) and negatively with levels of LH (P < 0.05), LH/FSH ratio (P < 0.0001), SHBG (P < 0.0001) and androstenedione (P < 0.01), whereas for levels of testosterone, FAI and DHEAS the impact of obesity differed significantly between the groups. Thus, in the PCOS group, testosterone levels (P < 0.05) and the FAI (P < 0.001) were positively associated with BMI, whereas they were constant throughout the entire range of BMI in the controls. DHEAS levels were positively associated with BMI in the PCOS group (P < 0.05) and negatively in the controls (P < 0.01). Measures of upper body fat were related to testosterone and FAI levels, independent of BMI. CONCLUSIONS: Lower FSH levels were found in women with PCOS than during the early follicular phase of normally ovulating women, suggesting a role in anovulation in PCOS. Obesity itself exerted effects on endocrine variables, with the net result of a reduced LH/FSH ratio and lower serum levels of androstenedione and SHBG in both groups; obesity was associated with increased levels of DHEAS, testosterone and FAI exclusively in the women with PCOS. The results underline the endocrine impact of obesity and body fat distribution and the necessity of applying reference values of BMI matched subjects when establishing the endocrine profile of women with PCOS.

Adult↗

PubMed1994

Amplitude regulation of episodic release, in vitro biological to immunological ratio, and median charge of human chorionic gonadotropin in pregnancy.

In the present study, we examined the regulation of 24-h serum immunoreactive levels, in vitro biological to immunological (B/I) ratio, and median charge of circulating CG at the end of the first, second, and third trimesters of human gestation. Seven pregnant women were prospectively studied at 12-15, 23-26, and 35-38 weeks of gestation. Blood was sampled every 20 min over a 24-h period, and serum CG concentrations were determined by RIA. Pulse detection and analysis of the 24-h rhythm of serum immunoreactive CG concentrations were carried out by the program Cluster and cosine curve fitting, respectively. The in vitro biological activity of circulating CG was determined by the mouse Leydig cell-testosterone production bioassay, and the median charge of its isoforms was determined by zone electrophoresis in agarose suspension. The immunoreactive levels of CG present at the end of each trimester of gestation fluctuated over a 24-h period; such variability exceeded that of the within-assay coefficient of variation of the CG RIA and could be resolved into a series of CG peaks and valleys. Although no trend in the number of peaks or valleys was systematically found in relation to gestational age, comparisons between the amplitude and area of the CG peaks revealed that these pulse parameters were significantly higher at 12-15 weeks than at 23-26 and 35-38 weeks of gestation. Cosine fits for 24-h rhythms revealed the existence of significant nyctohemeral profiles of serum CG levels in all women studied at 12-15 weeks, in four subjects at 23-26 weeks, and in six women at 35-38 weeks gestation. The time of acrophase was highly homogeneous only between 12-15 weeks of gestation, occurring between 1057-1452 h in six of the women. The in vitro B/I ratio of CG contained in serum pools from 12-15 weeks was significantly (P < 0.05) higher than that exhibited by CG during later gestational periods (B/I ratio at the end of first trimester, 1.14 +/- 0.14; second trimester, 0.87 +/- 0.22; third trimester, 0.79 +/- 0.12). hCG isoforms at 12-15 weeks were more negatively charged than those circulating at 23-26 and 35-38 weeks of gestation. There were no significant differences between the B/I ratio and the median charge of CG molecules from the second and third trimesters. We conclude that serial serum concentrations of CG throughout pregnancy show significant amplitude-modulated pulsatile release and nyctohemeral variations.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1994

A change in the isoforms of human chorionic gonadotropin occurs around the 13th week of gestation.

hCG exhibits a considerable heterogeneity in blood during pregnancy. The overall charge of the isoforms of hCG has been shown to be more negative in the early than in the latter part of pregnancy. The present study analyzes the change in median charge and the charge heterogeneity as pregnancy progresses. The hCG activity in sera from 76 women from weeks 6-43 of gestation was measured with a noncompetitive time-resolved sandwich fluoroimmunoassay. The median charge and degree of charge heterogeneity of the isoforms of hCG in each serum was determined by electrophoresis in 0.10% agarose suspension. Median charge was expressed as median electrophoretic mobility. Electrophoresis with a high resolution revealed that the number of isoforms of hCG in a serum specimen from week 36 of gestation was 20-30. A change in median charge was found to occur at a limited time period of gestation, around the 13th week. All 16 sera from weeks 6-10 had isoforms of hCG with a more negative median charge than that of hCG in 21 sera from weeks 16-43 of gestation. The change in charge was accompanied by an increased degree of charge heterogeneity. There was a significant (P < 0.01) correlation between median mobility and the concentration of hCG during weeks 11-15 of gestation, but not before or after this period. There was no relationship between the sex of the fetus and the median charge of the isoforms of hCG. The data show that a change in the isoforms of hCG, revealed by a change in median charge of hCG, occurs at a limited time around the 13th week of gestation. This change occurs when the hCG concentration in blood decreases, and the placental production of estradiol and progesterone rapidly increases.

Adult↗

PubMed1994

Serum gonadotropin isoforms become more basic after an exogenous challenge of gonadotropin-releasing hormone in children undergoing pubertal development.

Recent clinical studies have questioned whether there is a qualitative change in the circulating isoforms of LH and FSH after stimulation by GnRH. The present study investigated the median charge of serum gonadotropin isoforms before and after an exogenous challenge of 100 micrograms GnRH in 10 girls and 10 boys undergoing pubertal development. All of the children had basal serum levels of LH and FSH and responses 30 and 60 min after GnRH treatment that were considered normal for puberty. LH and FSH in serum and eluates after electrophoresis in 0.10% agarose suspension were measured with sandwich fluoroimmunoassays. The increases in serum gonadotropin concentrations were generally similar for both sexes, but girls had significantly (P < 0.05) higher LH levels at 30 and 60 min than boys and a larger (P < 0.05) relative increase in serum FSH levels after GnRH treatment. In terms of the median charge of serum isoforms, the girls had significantly less negative (i.e. more basic) isoforms of LH (P < 0.05) and FSH (P < 0.001) than the boys. There was a change to more basic isoforms of both LH and FSH in all children 30 min after GnRH administration. For LH, the charge had returned to pretreatment values by 90 min after GnRH, but for FSH, the charge was still significantly (P < 0.05) more basic at this time (n = 4/sex). When the LH isoforms were more acidic before GnRH treatment, the change in median charge was larger than when the isoforms were more basic beforehand. A similar relationship was not found for FSH. Conversely, there was for FSH, but not for LH, a significant (P < 0.001) relationship between the relative increase in serum concentrations and the change in charge of the isoforms 60 min after GnRH treatment. These findings show that the circulating forms of LH and FSH become more basic after an exogenous challenge of GnRH in children undergoing pubertal development and suggest that the differences in the responses of LH and FSH isoforms may be due to differing degrees of selective secretion and/or survival.

Adolescent↗

PubMed1994

Ultrasonographical and hormonal description of the normal ovulatory menstrual cycle.

OBJECTIVE: To describe the changes in uterine volume, endometrial thickness and follicular size during the normal menstrual cycle by use of transvaginal ultrasonography and to correlate these changes with the endocrine events in the same cycle. METHODS: A group of 23 healthy women with normal body mass index and with a history of regular menstruations were monitored with repeated hormonal and vaginal ultrasonographical investigations during the menstrual cycle. RESULTS: Sixteen of the women fulfilled the hormonal criteria for ovulation. The mean length of the cycles was 28 days (range 25-30 days) with a mean length of the follicular and the luteal phases of 14.4 days (range 12-17 days) and 13.5 days (range 12-16 days), respectively. The estradiol level in serum the day before the peak of the luteinizing hormone varied between 490 and 1710 pmol/l (mean 1087 pmol/l). Ultrasonographically, the most clinically relevant changes were the increase in diameter of the dominant follicle and the growth of the endometrium. At ovulation the dominant follicle had a mean diameter of 21.4 mm (range 17.4-27.0), whereas the endometrium had a mean thickness of 12.8 mm (range 10.0-15.9). When analysed over the entire follicular phase, the serum estradiol concentration correlated both with the diameter of the dominant follicle (r = 0.93, p = 0.0001) and with the thickness of the endometrium (r = 0.79, p = 0.0001). However, no such correlations were found when only the last part of the follicular phase was analysed. In the luteal phase there was no correlation between the size of the corpus luteum and the serum concentration of progesterone. CONCLUSIONS: Vaginal ultrasonography is a practical and reliable method to monitor structural changes in the ovaries and the uterus during the menstrual cycle. The results are of clinical importance for a better understanding of the physiological changes and helpful when monitoring induction of ovulation in assisted reproduction.

Adult↗

PubMed1993

Serum pituitary and sex steroid hormone levels in the etiology of prostatic cancer--a population-based case-control study.

The hypothesis that serum concentrations of pituitary hormones, sex steroid hormones, or sex hormone-binding globulin (SHBG) affect the occurrence of prostatic cancer was tested in a consecutive sample of 93 patients with newly diagnosed, untreated cancer and in 98 population controls of similar ages without the disease. Cases did not differ significantly from controls regarding serum levels of luteinising hormone (LH) or follicle stimulating hormone (FSH). Remarkably close agreement was found for mean values of total testosterone (15.8 nmol l-1 in cases and 16.0 in controls), and free testosterone (0.295 and 0.293 nmol l-1, respectively), with corresponding odds ratios for the highest vs lowest tertile of 1.0 (95% confidence interval 0.5-1.9) for testosterone and 1.2 (95% confidence interval 0.6-2.4) for free testosterone. Similar close agreement between cases and controls was found for serum concentrations of estradiol, androstenedione and SHBG, although the mean estradiol level was non-significantly (P = 0.30) lower among cases. Changes secondary to the disease were unlikely to have affected the results materially, since only LH and FSH were associated with stage of disease and this relationship was weak. Our findings suggest that further analyses of serum hormone levels at the time of diagnosis are unlikely to improve our understanding of the etiology of prostatic cancer.

Age Factors↗

PubMed1993

More basic forms of both human follicle-stimulating hormone and luteinizing hormone in serum at midcycle compared with the follicular or luteal phase.

The purpose of this study was to compare the heterogeneity and median charge of FSH and LH in serum at different phases of the normal human menstrual cycle. Serum specimens were obtained during the follicular phase [9.0 +/- 1.9 (+/- SD) days before the midcycle], at the midcycle LH peak, and during the luteal phase (9.75 +/- 1.6 days after the midcycle) in 16 women with normal menstrual cycles. The 48 serum specimens were subjected to electrophoresis in 0.17% agarose suspension in 0.075 M veronal buffer at pH 8.6, using a column suitable for measuring the median charge of the isoforms of FSH and LH, expressed as median electrophoretic mobility. Four sera were also analyzed by use of a larger column, giving a high resolution. The FSH and LH activities were measured with a time-resolved sandwich fluoroimmunoassay. The number of isoforms of both FSH and LH in each serum specimen analyzed by electrophoresis with high resolution was between 20-30. The median charge of the isoforms of FSH was less negative (P < 0.001) at the midcycle than in the follicular or luteal phase in all 16 women. The same was found for LH in 14 of 15 women. The median charge of FSH or LH in the follicular phase was not significantly different from that in the luteal phase of the cycle. We conclude that at least 20-30 isoforms of both FSH and LH circulate in blood during the menstrual cycle. More basic isoforms of both hormones appear in serum at midcycle than in the follicular or luteal phase. The difference is most likely due to a selective secretion from the pituitary of more basic forms of FSH and LH at midcycle.

Adult↗

PubMed1993

Large somatostatin-insensitive thyrotrophin-secreting pituitary tumour responsive to D-thyroxine and dopamine agonists.

A unique thyrotrophin (TSH)-secreting pituitary tumour is described in a patient with a history of recurrent thyrotoxicosis. Unlike other previously reported TSHomas, the tumour is insensitive to octreotide, a somatostatin analogue. It does not accumulate [111In]octreotide but expresses functional dopamine receptors and responds to the D-isomer of thyroxine, two characteristics beneficial in the management of the patient.

Bromocriptine↗

PubMed1993

Parathyroid hormone and osteocalcin levels in plasma and ultrafiltrate during hemofiltration.

The effects of hemofiltration (HF) on serum levels of intact parathyroid hormone (PTH), as well as its mid-C regional and C-terminal fragments and bone Gla-protein (bone gamma-carboxyglutamic acid, osteocalcin), were investigated in 17 patients during one session of HF. During HF there was a significant decrease in the serum concentrations of both intact PTH (p < 0.01), mid-C regional PTH (p < 0.01) and C-terminal PTH (p < 0.01) as well as in the osteocalcin concentrations (p < 0.01). There was a significant increase in serum calcium (p < 0.05) during the procedure and this increase correlated with the reduction in PTH (r = 0.56, p < 0.05). Mid-C regional PTH and osteocalcin were found in the ultrafiltrate of all patients, while intact PTH was found in the ultrafiltrate of 8 of 17 patients and C-terminal PTH was detected only in the ultrafiltrate of one patient. The data demonstrate that the permeability of HF membranes is high enough to cause filtration of both intact PTH, PTH fragments and osteocalcin. An inhibited secretion of PTH probably played a major part in reducing intact PTH in serum during HF.

Adult↗

PubMed1992

Serum erythropoietin in the diagnosis of polycythaemia and after phlebotomy treatment.

Serum erythropoietin (S-Epo) was measured with a radiommunoassay method in 36 patients with polycythaemia vera, 17 patients with secondary polycythaemia and 14 patients with relative polycythaemia. The diagnoses were made without the aid of the S-Epo values. It was found that S-Epo was below the reference range in 34/36 patients with polycythaemia vera (mean 2.1 +/- 1.0 U/l), elevated in all cases of secondary polycythaemia (mean 121.7 +/- 242 U/l) and normal in all but one of the cases with relative polycythaemia (mean 7.0 +/- 2.5 U/l). Previous studies of S-Epo levels in the differential diagnosis of polycythaemia have shown significant differences between the means of the groups but a considerable overlap. After phlebotomy treatment to normal haematocrit levels, the S-Epo levels remained subnormal in most of the polycythaemia vera patients even after 18 months at a haematocrit around 45%. Two patients who had been kept at normal haematocrit for 6 and 7 years both had subnormal S-Epo. We conclude that with an Epo assay method of high sensitivity and specificity it is possible to differentiate between different forms of polycythaemia with a high degree of certainty, even between patients with relative polycythaemia and polycythaemia vera patients. The reason why S-Epo remains low in spite of a normal haematocrit in treated polycythaemia vera patients is not known.

Bloodletting↗

PubMed1992

Response of anaemia in rheumatoid arthritis to treatment with subcutaneous recombinant human erythropoietin.

Eleven patients with chronic inflammatory arthritides and haemoglobin concentrations less than 105 g/l with symptoms from their anaemia were treated with a dose of 250 IU/kg/week of recombinant human erythropoietin for six weeks. The treatment was given as subcutaneous injections five days a week. All patients had active inflammatory disease. Nine patients responded to treatment with an increase in haemoglobin of more than 15 g/l. The mean (SD) haemoglobin concentration increased from 93.0 (8.0) g/l before treatment to 115.0 (12.0) g/l after six weeks. There was no correlation between the initial serum concentration of erythropoietin and the response. It was concluded that anaemia in chronic inflammatory arthritides responds to treatment with subcutaneous injections of recombinant human erythropoietin.

Administration, Cutaneous↗

PubMed1992

Clinical and genetic features of adrenocortical lesions in multiple endocrine neoplasia type 1.

In multiple endocrine neoplasia type 1 (MEN-1), benign enlargement of the adrenal cortex has been found in about one third of necropsy cases. To elucidate the clinical and genetic characteristics of the MEN-1 adrenal lesion, we have investigated 33 MEN-1 patients. Twelve individuals (37%) demonstrated adrenal enlargement, which was bilateral in 7 of them. Histopathology revealed diffuse and nodular cortical hyperplasia, adenomas, and a single case of adrenocortical carcinoma. The apparently benign adrenal enlargements were not associated with presently ascertainable biochemical disturbances in the hypothalamic-pituitary-adrenocortical axis, and they were without radiological signs of progression during follow-up. The individual developing unilateral adrenocortical carcinoma showed rapid adrenal expansion, feminization, and an abnormal urinary steroid profile after 4 yr of observation for bilateral minor adrenal enlargements. Pancreatic endocrine tumors were significantly overrepresented and present in all MEN-1 individuals with adrenal involvement. In agreement with findings in sporadic cases, the MEN-1 adrenocortical carcinoma genome showed loss of constitutional heterozygosity for alleles at 17p, 13q, 11p, and 11q. The benign adrenal lesions retained heterozygosity for the MEN-1 locus at chromosome 11 q 13. Despite its prevalence and malignant potential, the pituitary-independent adrenocortical proliferation does not appear to be a primary lesion in MEN-1, but might represent a secondary phenomenon, perhaps related to the pancreatic endocrine tumor.

Adrenal Cortex↗

PubMed1992

Parathyroid function in relation to intestinal function and renal calcium reabsorption in patients with nephrolithiasis.

Recently a technique to measure intact parathyroid hormone (PTH), i.e. the biologically active hormone, has been available. The aim of the present study was to apply this method to evaluate the parathyroid function in a material of recurrent renal stone formers (n = 324). Intact PTH was found to be inversely related to both urinary calcium (r = -0.15; p less than 0.01) and serum calcium (p less than 0.02) indicating that in the majority of the patients with hypercalciuria this was accounted for by intestinal hyperabsorption and not by high serum PTH. Hyperabsorption was also the likely explanation for the finding of a positive relationship between the urinary calcium and oxalate excretions (r = 0.22; p less than 0.001) in medication-free patients without intestinal disorders, i.e. without enteric hyperoxaluria. Altogether 25 patients (7%) had elevated serum PTH concentrations. They were followed up with fasting serum and urinary electrolytes and an oral calcium loading test (1 g of calcium) in order to evaluate the importance of renal and intestinal factors responsible for the elevated serum PTH concentrations. The investigation was carried out on a free diet and on low and high calcium intakes, respectively. The incidence of intestinal malfunction, which was sometimes present without clinical symptoms, was found to be approximately the same as that of impaired renal conservation of calcium. The findings in the patients with intestinal malfunction were a reduced intestinal absorption of calcium and an enhanced tubular reabsorption of calcium (TRCa), with greater reabsorption of calcium for higher PTH values. In patients with impaired renal conservation of calcium despite the raised PTH there was no correlation between PTH and TRCa. When PTH was suppressed during the oral calcium load the TRCa was found to be inappropriately low and the renal defect obvious. The intestinal calcium absorption was secondarily increased to compensate for the renal losses.

Adolescent↗

PubMed1992

Metabolic cardiovascular risk factors and the renin-aldosterone system in essential hypertension.

Impairment of glucose and lipid metabolism is common in hypertensive subjects. In the present study the relationships between indices of lipid and glucose metabolism and the renin-aldosterone system were studied in 37 untreated hypertensive subjects (DBP greater than 95 mmHg). Fasting insulin and the early insulin response at an intravenous glucose tolerance test were both correlated to plasma renin activity (r = 0.48, P less than 0.003 and r = 0.55, P less than 0.002, respectively) while HDL-cholesterol was found to be inversely related to the urinary excretion of aldosterone (r = 0.35, P less than 0.03). These relations were still significant when influences of age, sex, obesity (BMI) and serum creatinine were taken into account in the multiple regression analysis. In conclusion, hyperinsulinaemia and low levels of HDL-cholesterol were found in hypertensive subjects with a high activity of the renin-aldosterone system and might explain the high incidence of cardiovascular diseases found in this group.

Adult↗

PubMed1991

Cerebrospinal fluid calcium, parathyroid hormone, and monoamine and purine metabolites and the blood-brain barrier function in primary hyperparathyroidism.

Psychiatric disturbances are common in primary hyperparathyroidism (HPT), but their pathogenesis is essentially unknown. This study deals with cerebrospinal fluid (CSF) calcium homeostasis and its connection with parathyroid hormone (PTH), blood-brain barrier (BBB) function, and central monoamine and purine metabolites in patients with primary HPT. In 22 patients with primary HPT (serum calcium 2.85 +/- 0.21 mmol/l), the CSF concentrations of total and ionized calcium were higher (1.21 +/- 0.08 mmol/l, p less than 0.01, and 1.09 +/- 0.05 mmol/l, p less than 0.001, respectively) than in 11 normocalcemic reference subjects. The values correlated with serum calcium concentration (p less than 0.001) and CSF/serum albumin ratio, a measure of BBB permeability. The latter ratio was elevated in one-third of the patients with HPT, indicating BBB damage. CSF immunoreactive intact PTH was higher in the HPT patients than in the reference group (p less than 0.05), and serum and CSF PTH were positively correlated (p less than 0.05). The CSF levels of the monoamine metabolites 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA) were lower, and the level of urate in CSF was higher, in the HPT patients than in the reference subjects, while there were no consistent differences in CSF hypoxanthine or xanthine. CSF 5HIAA correlated inversely with CSF ionized calcium (r = -0.42, p = 0.02). After parathyroid surgery, CSF calcium and urate decreased significantly and CSF monoamine metabolites increased slightly. The decrease in CSF ionized calcium correlated with the alleviation of psychiatric symptoms. The results indicate the importance of increased CSF calcium concentrations in patients with primary HPT and suggest a relation between central calcium regulation and central turnover of monoamines.

Blood-Brain Barrier↗

PubMed1991

Skeletal responsiveness to parathyroid hormone in healthy females: relationship to menopause and oestrogen replacement.

In order to directly evaluate the role of parathyroid hormone (PTH) and its interaction with oestrogens for postmenopausal bone loss, studies were performed where synthetic human (1-38) PTH was infused s.c. over 24 h in 15 healthy females. Measurements were made of serum electrolytes, PTH and biochemical indices of bone turnover: serum osteocalcin and alkaline phosphatase and fasting urinary hydroxyproline and calcium. During the infusion of PTH there were significant increases of serum calcium (15%), fasting urinary calcium (55%) and hydroxyproline (80%) but a reduction of the serum osteocalcin concentrations (15%). There were significant relations between the calcaemic response and the increases of urinary calcium and hydroxyproline and the two latter were also closely related. There was, however, no correlation between the responses to PTH for the formative vs the resorptive indices. Postmenopausal women displayed greater increases of serum calcium and fasting urinary hydroxyproline indicating greater skeletal sensitivity to exogenous PTH. Following treatment with oestrogens the indices of skeletal responsiveness were reversed towards the premenopausal values. The findings demonstrate that during short-term infusion of PTH there is a dissociation between bone resorption and formation and, furthermore, that the menopause is associated with an enhanced skeletal sensitivity for PTH.

Adult↗