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Biomedical subjects

L Skovsted

Publications and source records attributed to L Skovsted.

At least 19 recordsLinked to original sources
PubMed1991

The thyroid function and size in healthy man during 3 weeks treatment with beta-adrenoceptor-antagonists.

The influence of beta-adrenoceptor antagonists on serum TSH level (supersensitive method) and thyroid volume has not previously been studied. Thirty-two young non-smoking males were treated for 3 weeks with either atenolol 50 mg (b.i.d.), metoprolol 100 mg (b.i.d.) or propranolol 80 mg (b.i.d.) in a placebo controlled study. After 1 week, median serum TSH level increased in the atenolol (from 1.76 (range: 0.96-4.04) to 2.25 (range: 1.11-4.22) mU/l, P less than 0.05) and propranolol (from 1.91 (range: 0.90-3.83) to 2.44 (range: 0.75-6.30) mU/l, P less than 0.05) treated groups. After 3 weeks, median serum TSH reached pretreatment level in the atenolol treated, whereas median serum TSH decreased compared to pretreatment values in the propranolol treated (1.68 (range: 0.68-3.62) mU/l, P less than 0.05). Except for a slight increase in the atenolol treated group, no changes in median thyroid volume was seen after 3 weeks. The changes in serum TSH or thyroid volume were not related to changes in the concentrations of thyroid hormones, or of a magnitude likely to interfere with the clinical evaluation of thyroid function.

Adrenergic beta-Antagonists↗
PubMed1990

Acute beta-blockade changes the extracellular distribution of thyroid hormones.

The acute (within hours) changes in the concentrations of T4, T3, reverse-T3 (rT3) and T3 resin uptake test (T3RU) were studied in 31 hyperthyroid patients for 4 h after po treatment with either acebutolol, oxprenolol, pindolol or timolol. In 21 of the patients, the changes were compared to changes in the serum concentrations of alpha 2-macroglobulin (a macromolecule) and two middle-sized molecules; thyroid hormone-binding globulin (TBG) and albumin in order to calculate the changes in extracellular distribution of the thyroid hormones and to distinguish between changes due to a changed metabolism and changes due to a changed distribution of the thyroid hormones. Acebutolol, oxprenolol and timolol caused a decrease in serum T3 after 1/2 h, and acebutolol and oxprenolol also a decrease in rT3 after 1/2 - 1 h, the changes reversed within 2 h. A concomitant decrease in serum albumin and TBG suggests a change in the extracellular distribution of middle-sized molecules to which thyroid hormones are attached, as an explanation of the acute decrease (1 h) of the thyroid hormones. The small and insignificant change in alpha 2-macroglobulin indicates that the changes are mainly extravascular, but the difference of alpha 2-macroglobulin changes between the drugs (acebutolol/timolol vs pindolol/oxprenolol) could depend on the intrinsic sympathomimetic activity of the drugs.

Acebutolol↗
PubMed1979

Serum T4, T3 and reverse T3 during treatment with propranolol in hyperthyroidism, L-T4 treated myxedema and in normal man.

Serum concentrations of T4, T3 and reverse T3 were studied in two hyperthyroid groups (n = 13 and 11), in a group of normals (n = 9) and in a group of L-T4 substituted patients (n = 7) with severe pretreatment hypothyroidism. Serum T4 did not change except in one of the hyperthyroid groups change to in which a slight decrease was found. In all groups a significant fall in serum T3 and a significant rise in serum reverse T3 were found. An expected increase in serum TSH in the normal and in the L-T4 substituted groups could not be demonstrated.

Adult↗
PubMed1979

Influence of age on the endocrine-metabolic response to surgery.

The pathogenesis of the increased operative risk in elderly patients is unknown. From a theoretical point of view, a change in endocrine-metabolic response might be involved. In the present study, a battery of hormonal and metabolic variables were measured in eight young and eight elderly healthy males undergoing elective inguinal hernial repair under general anesthesia. Blood was drawn before induction of anesthesia, at skin incision, and one, two, and six hours after skin incision. The findings were: 1) Plasma cortisol increase was significantly higher in elderly than in young controls. 2) Plasma renin level was lower in old age, but renin-aldosterone and electrolyte response patterns were alike in the two groups. 3) Thyroid parameters, in terms of serum T4, serum T3, serum rT3, and T3-resin uptake, responded normally to surgery and showed no age-related differences. 4) The hyperglycemic response was not significantly influenced by age indicating unchanged glycoregulatory mechanisms also verified by determinations of plasma catecholamines, cAMP, and insulin. 5) Blood lymphocyte count was constantly lower in elderly than in young and decreased with time, but the age-related difference was not significant. 6) Blood polymorphonuclear leukocytes showed an increase of the same magnitude in both age groups, although at a significantly slower rate in the elderly. It is concluded that age affects some aspects of the initial endocrine-metabolic response to surgery.

Adult↗
PubMed1979

Radioimmunoassays of T3, r-T3 and r-T'2 in human serum.

Simple radioimmunoassays for 3,3',5-triiodothyronine (T3), 3,3',5'-reverse-triiodothyronine (r-T3) and 3,3'-diiodothyronine (r-T'2) in human serum are described. The princple of the methods is the same and based on a system using 8-anilino-1-naphthalene sulfonic acid as an inhibitor of nonspecific protein binding, a simultaneous addition of the antibody and the labelled hormone, an overnight incubation at room temperature and a separation of bound and free hormone with dextran-coated charcoal. The methods require 15 microliter, 50 microliter and 100 microliter (or 333 microliter for ethanol extraction) serum respectively. Serum concentrations (mean +/- SD) of T3, r-T3 and r-T'2 from normal subjects are 144 +/- 19 ng T3/100 ml (n = 52), 32 +/- 7 ng r-T3/100 ml (n = 36), 3.8 +/- 0.7 ng r-T'2/100 ml (ethanol extraction, n = 18) and 8.2 +/- 1.6 ng r-T'2/100 ml (unextracted, n = 16).

Diiodothyronines↗
PubMed1979

The effect of suppressive therapy of nontoxic diffuse goiter on serum levels of thyroxine, 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine.

We studied the effect of suppressive therapy with graded doses of thyroxine (T4) on serum levels of T4, 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyronine [rT3] in patients with diffuse, nontoxic goiter. For comparison and in order to elucidate the degree of suppression of the pituitary thyroid axis by T3 the effect of suppressive therapy with T3 was studied in the same type of patients. We found that T4 in serum rose significantly to a constant level during T4 treatment (0.10, 0.15 and 0.20 mg/day). Dose-related rises in T4 were only seen after 3 months of treatment. T3 and rT3 only changed minimally. The T4/T3 ratio rose to a constant level during the initial 3 months of treatment. T3/rT3 ratio remained unchanged. No dose-related differences in T4/T3 and T3/rT3 ratio were observed. Treatment with T3 in doses of 0.06 mg per day caused a significant but slow fall in T4 and rT3 to hypothroid levels while T3 only rose slightly. The T4/T3 ratio dropped significantly during T3 therapy.

Adult↗
PubMed1979

The effect of different sulfonamides on phenytoin metabolism in man.

The influence on the metabolism of phenytoin of some sulfonamides given in common clinical doses has been studied. In single dose experiments sulfaphenazole increased phenytoin half-life (T/2) by 237% and decreased phenytoin metabolic clearance rate (MCR) by 67%. Sulfadiazine, sulfamethiazole, sulfamethoxazole + trimethoprim and trimethoprim increased phenytoin T/2 by 80, 66, 39 and 51% respectively, and decreased phenytoin MCR by 45, 36, 27 and 30% respectively. Sulfamethoxazole gave a small but significant increase in phenytoin T/2 but not a corresponding fall in phenytoin MCR. No changes were found in phenytoin T/2 and MCR after treatment with sulfamethoxypyridazine, sulfadimethoxine and sulfamethoxydiazine. Steady state experiments confirmed the findings of the single dose experiments. It is suggested that sulfaphenazole, sulfadiazine, sulfamethizole, sulfamethoxazole + trimethoprim and trimethoprim inhibit hepatic metabolism of phenytoin.

Adult↗
PubMed1979

Abnormal gamma globulin binding of thyroid hormones.

Thyroid hormone levels were studied in a thyrotoxic patient, who was treated with propylthiouracil. He had heavily increased triiodothyronine concentrations, measured by radioimmunoassay, in spite of only mild clinical symptoms of thyrotoxicosis. A moderately increased serum triiodothyronine concentration was observed in another patient, who was euthyroid and who had recently recovered from subacute thyroiditis. By gel electrophoresis and precipitation tests with human anti-IgG and anti-IgA, a binding to the gamma globulins of both triiodothyronine and thyroxine was detected in patient 1, and of triiodothyronine in patient 2. Such abnormal binding may result in serious errors in the determination of thyroid hormone concentration by radioimmunoassay.

Adult↗
PubMed1979

L-thyroxine treatment of diffuse non-toxic goitre evaluated by ultrasonic determination of thyroid volume.

The effect of a daily dose of 150 micrograms l-thyroxine for one year was studied in forty-five patients with diffuse non-toxic goitre. Thyroid volume was evaluated by ultrasonic scanning. A decrease in the median value of the thyroid volume of about 20% was found after 3 months of therapy and no further change in the median value was observed in the following 9 months of treatment. About 50% of the patients showed a response to therapy and about 30% obtained normal size of the thyroid gland. Median value of the thyroid volume returned to pretreatment value 3 months after thyroxine therapy was stopped. A considerable increase in serum T4 and free T4 index was noted after 3 months of therapy and these elevated values persisted unaltered during the following 9 months of treatment. Serum T3 was studied before and after 3 months of thyroxine therapy in eleven of the patients. A small and insignificant increase in serum T3 and free T3 index was observed.

Adult↗
PubMed1979

Effect of exercise on thyroid parameters and on metabolic clearance rate of antipyrine in man.

UNLABELLED: Serum concentrations of thyroxine, triiodothyronine, free-thyroxine-index, free-triiodothyronine-index and reverse-triiodothyronine (r-T3) were followed in nine normal men, aged 18 to 22 years, during a nights rest and during nine hours march (4.6 km/h). In addition antipyrine elimination was measured in the same periods after iv injection of 1 gram of antipyrine. No significant differences were found in any of the thyroid parameters during exercise except for a small increase in serum r-T3 after 3 hours. During rest a small but significant decrease was found in serum r-T3. Otherwise no significant differences were found except for a significant increase in free-T3-index after 3 hours rest. The mean value of total body clearance of antipyrine was identical at rest and during exercise. IN CONCLUSION: Prolonged exercise does not change the metabolic clearance rate of antipyrine and does not elicit any major change in the serum concentrations of the thyroid hormones.

Adolescent↗
PubMed1978

The preferential role of triiodothyronine in the regulation of basal metabolic rate in hyper- and hypothyroidism.

The free triiodothyronine index (FT3I) was significantly correlated to basal metabolic rate (BMR) in hyperthyroid (r=+0.63, p less than 0.01) and hypothyroid patients (r=+0.61, p less than 0.05). Elimination of the effect of the free thyroxine index (FT4I) on the total correlation between BMR and FT3I by partial correlation analysis gave partial r=+0.60, p less than 0.01 in hyperthyroid patients and partial r=+0.43, p less than 0.1 in hypothyroid patients. The FT4I did not correlate to BMR in either hyper- or hypothyroid patients. These results point to triiodothyronine as the major regulator of BMR in hyper- and hypothyroidism.

Basal Metabolism↗
PubMed1978

Myxoedema and thyrotoxicosis: relations between clinical state and concentrations of thyroxine and triiodothyronine in blood.

The clinical manifestations in thyrotoxic and myxoedematous subjects were assessed by clinical diagnostic score indices and related to the free thyroxine index (FT4I) and the free triiodothyronine index (FT3I), basal metabolic rate (BMR) and in the hypothyroid patients to serum thyrotropin (TSH) level. The clinical score index was significantly correlated to both FT4I and FT3I in both groups of patients. No difference existed in degree of correlation between the clinical score index, on the one hand, and FT3I and FT4I, on the other, in either thyrotoxic or myxoedematous subjects. The degree of correlation between clinical score index and FT3I and FT4I was higher than that between the thyroid hormones and BMR. The clinical score index thus appears to be a better indicator of severity of hyper- and hypothyroidism than BMR. Serum TSH concentration was not correlated to the clinical state.

Adult↗
PubMed1978

Unaltered metabolism of phenytoin in thyroid disorders.

The metabolism of phenytoin was studied in 9 hyperthyroid and 7 hypothyroid patients before and after treatment with either antithyroid drugs or 1-thyroxine. No difference in the half-life, volume of distribution and metabolic clearance rate was found between untreated hyper- and hypothyroid subjects. Furthermore, normalisation of thyroid function test did not change the kinetic parameters of phenytoin. The results indicate that the well-known correlation between thyroid function and antipyrine kinetics cannot be extrapolated uncritically to other drugs. It is concluded that no general rules are valid in the kinetics among different drugs in thyroid pathological conditions. Each drug must be evaluated by itself in different pathological conditions.

Adult↗
PubMed1978

The relationship between levels of thyroid stimulating hormone and of thyroxine and triiodothyronine in blood of hypothyroid patients.

Serum TSH values and the free concentration of T4 and T3 in serum expressed as the free T4- and T3-indices showed a curvilinear relationship in 24 patients with manifest hypothyroidism mainly due to extremely elevated serum TSH levels associated with very low thyroid hormone levels. The same degree of negative correlation was found between the log serum TSH concentration and serum free T4-index (r = -0.51, P less than 0.05) and between log serum TSH concentration and serum free T3-index (r = -0.47, P less than 0.05). The correlation coefficients dropped to non-significant levels when the interdependence between the free T3- and T4-indices was taken into account and eliminated by partial correlation analysis. The degree of negative correlation between serum TSH and the thyroid hormones was also of the same order of magnitude in 5 hypothyroid patients studied prosepctively during treatment with L-thyroxine (TSH vs. T4: mean r = -0.71; TSH vs T3: mean r = -0.79).

Female↗
PubMed1978

Influence of thiazides on thyroid parameters in man.

Iodine metabolism and thyroid hormones in blood were studied in 19 men and 11 women who had been treated with thiazides for arterial hypertension from 1 month to 15 years. The results were compared with the findings from age-matched normal controls. No differences were found regarding 24-h 131I-thyroid uptake, thyroid iodide clearance, renal iodide clearance, plasma inorganic iodide, absolute iodine uptake (AIU), serum thyroxine (T4 (D)), resin T3 test (T3U) and TSH after TRH. Twenty-four-hour urinary iodine was higher in the patients treated with diuretics which could be explained by increased iodine intake. The findings of increased serum triiodothyronine (T3 (RIA)) and reverse T3 (rT3) might be due to changes in distribution volume in the thiazide-treated patients. Long-term treatment with thiazides in man do not lead to iodine depletion.

Adult↗
PubMed1976

Rapid decrease in plasma-triiodothyronine during surgery and epidural analgesia independent of afferent neurogenic stimuli and of cortisol.

Changes in circulating triiodothyronine (T3), thyroxine (T4), binding of thyroid hormones to plasma proteins (resin-T3 test), cortisol, and glucose were evaluated in sixteen patients undergoing abdominal hysterectomy. In eight of the patients afferent neurogenic impulses from the surgical area were blocked during and after operation by epidural analgesia. These patients were pain-free, and the normal stress-induced increase in cortisol and glucose was abolished. During epidural analgesia and general anesthesia plasma-T3 fell rapidly and values in the hypothyroid range were found 6 hours after skin incision. Similarly, an increase in the resin-T3 test reflected decreased binding of T3 to plasma proteins. Plasma-T4 decreased slightly during surgery and epidural analgesia (as it does when other anaesthetics are given), but increased during general anaesthesia. These results indicated that the alterations in thyroid hormones and their binding to plasma proteins after surgery are not caused by a stress-induced increase in plasma-cortisol or by neurogenic afferent stimuli from the surgical area, factors which are both known to affect concentrations of other hormones.

Adult↗
PubMed1976

The influence of disulfiram on the half life and metabolic clearance rate of diphenylhydantoin and tolbtamide in man.

Diphenylhydantoin (DPH) and tolbutamide serum levels were studied in ten volunteers before and after 4 days of disulfiram treatment. The mean DPH half life increased significantly from 11.0 +/- a.2 h to 19.0 +/- 3.3 h, and the mean DPH metabolic clearance rate decreased significantly from 51.2 +/- 17.2 ml/min to 33.9 +/- 12.0 ml/min during medication. No significant changes in the half life or metabolic clearance rate of tolbutamide was observed.

Adult↗