Search PubMed⌕ Search

Biomedical subjects

V Felt

Publications and source records attributed to V Felt.

At least 109 records · Page 6Linked to original sources
PubMed1977

Effect of bromocryptine on the secretion of thyrotropic hormone (TSH), prolactin (Pr), human growth hormone (HGH), thyroxine (T4) and triiodothyroxine (T3) in hypothyroidism.

Bromocryptine (CB-154) virtually abolished the rise of serum Pr after TRH stimulation in hypothyroid and euthyroid subjects. The response of serum TSH to TRH stimulation was significantly depressed in hypothyroid but not in euthyroid subjects. No significant changes of serum HGH, T4 and T3 after CB-154 were observed. The dual mode of action of CB-154 in pituitary and hypothalamus is discussed.

Adult↗
PubMed1977

Binding of thyroxine and triiodothyronine in solubilized nuclear extract of human leukocytes.

An in vitro study was carried out of the interaction of thyroidal hormones with leukocytes and with a solubilized extract of the nuclear fraction of human leukocytes. The respective association constants characterising the binding of triiodothyronine (T3) and thyroxine (T4) to whole leukocytes are roughly equal (for T3, KA = 3.1 X 10(11) 1/mol and for T4, KA = 4 X 10(11) 1/mol) but a 0.4 KCl extract of the nuclear fraction exhibits a different affinity to T3 (KA = 2.16 X 10(11) 1/mol) in comparison with T4 (KA = 1.3 X 10(10) 1/mol). In the nuclear extract, both hormones are bound with the affinity higher for T3 than for T4. The soluble nuclear binding protein in human leukocytes had a molecular weight 46 000, was chromatographically homogenous in chromatography on Sepharose 2B and Sephadex G200, and exhibited a longlasting stability at -25 degrees C, without any marked change in the binding affinity to thyroidal hormones.

Cell Nucleus↗
PubMed1977

Interaction of thyroid hormones with human muscular tissue, leucocytes and adipose tissue in vitro.

The uptake of triiodothyronine (T3) and thyroxine (T4) by human leucocytes as well as by adipose and muscular tissues in vitro was markedly dependent on the extracellular protein concentration. The presence of extracellular protein was responsible for the difference in the uptake of T3 and T4 by leucocytes (the incorporation of T4 was significantly lower than that of T3), whereas its presence in the medium containing adipocytes did nto influence the incorporation values. In a protein-free medium, the muscular tissue uptake of T3 exceeded that of T4. In this tissue the deiodination of both hormones was likewise significantly different, that of T4 being higher. The conversion of T4 to T3 was also higher in the muscle cells, but represented only about 75% of the total deiodinated fraction. In the remaining tissues, no differences were observed in the uptake and deiodination of T3 and T4. The deiodination of T4 in human leucocytes was found to be considerably dependent of pH of the incubation medium (two deiodination optima, a higher one in acid region) whereas the deiodination of T3 was fairly indifferent to variations of pH (one flat deiodination optimum in the weakly alkaline region).

Adipose Tissue↗
PubMed1976

Rapid and effective separation of thyroid hormones and iodide by thin-layer chromatography.

The use of 1,3-dichlorotetrafluoroacetone allows the conversion of the iodoamino acids into a chemical form convenient for following chromatographic separation on silica as an adsorbent and benzene or chloroform as a solvent. The time required for derivatization and TLC separation is less than one hour. The outstanding resolution of the substance of interest, as well as the sensitivity of the radiochemical analysis, makes the method convenient for the rapid determination of minute quantities of thyroid hormones.

Chromatography, Thin Layer↗
PubMed1976

The influence of thyroid function on the diabetogenic action of triamcinolone in man. Glucose, insulin and growth hormone patterns after on oral glucose load.

In subjects with varying thyroid function (12 hypothyroid, 11 euthyroid and 12 hyperthyroid) an oral glucose tolerance test was performed without sensitization (OGTT) and after sensitizing with triamcinolone (TGTT). The blood glucose, serum immunoreactive insulin (IRI) and growth hormone (HGH) levels were assessed. In hypothyroid subjects a marked deterioration of the glucose tolerance was found during the TGTT as compared with OGTT, a reduction of the glucose disappearance index (GDI) and almost unchanged IRI values. The decrease of insulinogenic index (II) was not significant. In euthyroid subjects the decrease of glucose tolerance after triamcinolone was only mild, GDI values remained unaltered, IRI values and II increased. In hyperthyroid persons the decrease of glucose tolerance during TGTT was even less pronounced than in the euthyroid group, although the IRI value increased only on fasting. No significant differences of HGH pattern were observed in any group. In our patients the diabetogenic effect of triamcinolone was inversely related to the saturation with thyroid hormones and an increased response of insulin to glucose load was observed only in euthyroidism. In hyperthyroidism the participation of non-insular factors in the mechanism of maintaining the glucose tolerance after triamcinolone should be assumed.

Adult↗
PubMed1976

Diabetogenic effect of triamcinolone in man with impaired thyroid function: serum free fatty acids, inorganic phosphorus, calcium and total protein pattern after an oral glucose load.

In a group of 35 subjects (12 hypothyroid, 11 euthyroid and 12 hyperthyroid) the changes of FFA, inorganic phosphorus, calcium and total proteins were investigated during glucose tolerance test with (TGTT) or without (OGTT) triamcinolone pretreatment. In hypothyroidism the decrease of FFA during TGTT was blunted, whereas the pattern of phosphatemia was unaltered and total proteins were increased. In euthyroidism triamcinolone exerts the opposite effect on the behaviour of FFA (decline was smaller and shorter) and phosphatemia (decline was pronounced and persists for longer period). In hyperthyroidism the fasting level of FFA decreased in TGTT but during the test no significant differences in FFA and phosphatemia patterns were observed. The calcemia was not influenced by triamcinolone in any subgroup. Our results suggest the importance of thyroid function as modifying factor in some metabolic effects of triamcinolone in man. Changes in hypothyroidism are in good agreement with changes of blood glucose and insulinemia, as described previously. Opposite effect of triamcinolone on FFA and phosphatemia pattern in euthyroidism may suggest the changes of sensitivity of some peripheral tissues to insulin action. The decline of fasting level of FFA after triamcinolone in hyperthyroidism is surprising and might be of importance in maintaining unaltered glucose tolerance after triamcinolone in this subgroup.

Blood Proteins↗