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Biomedical subjects

V Felt

Publications and source records attributed to V Felt.

At least 73 records · Page 4Linked to original sources
PubMed1981

Comparison of metabolic effects of glucagon and calcitonin and assessment of direct effect of glucagon on calcitonin level in athyroid man.

The effect of intramuscular administration of glucagon (Glg) and calcitonin (Ct) on the pattern of serum calcium (Ca), in organic phosphorus (P), blood glucose (BS), immunoreactive insulin (IRI) and growth hormone (GH) was investigate in 14 patients after total thyroid ablation during replacement therapy. In seven patients the pattern of Ct after Glg administration was assessed in the same conditions. Both hormones induced a prompt and marked decrease of Ca with out any differences between effect of Glg and Ct. The decline of P due to Glg is more rapid and marked than the due to Ct, the difference being significant from 60 to 120 min. Glg caused a rapid and marked rise of BS and IRI with a tendency toward normalization up to 180 min, GH rose significantly from 120 to 180 min. The changes of BS and IRI due to Ct were slow and less marked, but prolonged: level of BS increased and that of IRI decreased. No effect of Ct administration on GH was recorded. In general, neither the effects of Glg nor those of Ct were influenced by hypothyroidism. This fact may be of importance for use of Glg in testing GH reserve in hypothyroidism. Ct after Glg administration in athyroid patients failed to exhibit any significant changes. Thus our results support the assumption about similar and independent action of Glg and Ct on calcium and phosphate homeostasis and different effects of both hormones on glucose metabolism.

Adult↗
PubMed1981

Interaction of thyroid hormones and cortisol on binding proteins of cytosol and nuclear extract of human leukocytes.

Competitive properties of thyroid hormone analogues and cortisol for the binding of triiodothyronine and thyroxine, expressed as apparent inhibition constants (Ki), have been measured in nuclear extract and cytosol proteins of human leukocytes by means of electrophoresis in polyacrylamide gradient gel and charcoal-dextran assay. In the cytosol not only thyroid hormones but also cortisol competed for the binding of triiodothyronine and thyroxine as tested by charcoal-dextran assay. By means of electrophoresis two protein fractions binding thyroid hormones were found: protein fraction designed A (m. w. 100,000) and protein fraction B (m. w. 83,000). In protein fraction A the inhibition constant Ki for thyroid hormones are lower than in protein fraction B. In the protein fraction B not only thyroid hormones but also cortisol competed for the binding of triiodothyronine and thyroxine. In the nuclear extract the thyroid hormones were bound in one protein fraction C (m. w. 58,000) only. In this protein fraction only thyroid hormones, but not cortisol, are competitors for the binding of triiodothyronine and thyroxine and in the following descending order: triiodothyronine, thyroxine, tetraiodothyroacetic acid, thyroxamine and D-thyroxine. The competition of cortisol for the binding of thyroid hormones in cytosol protein fraction B in connection with some serum TBG changes in patients after prednisone administration is discussed.

Cell Nucleus↗
PubMed1981

Some effects of triamcinolone pretreatment on intravenous glucose tolerance test in patients with different thyroid function.

In 42 patients (17 hypothyroid -Hypo, 14 euthyroid -Eu and 11 thyrotoxic -TX) the intravenous glucose tolerance test was performed before and after triamcinolone sensitization. The blood sugar (BS), immunoreactive insulin (IRI), growth hormone (GH), inorganic phosphorus (P), calcium (Ca), and total proteins (TP) were assessed and glucose disappearance rate was calculated from absolute values (KGt) and from increments (KGi) of glucose. Triamcinolone caused a rise of BS in Eu an Tx subgroups and a decrease of KGt and KGi in Hypo and decrease of KGt in Tx. No differences were found in patterns of IRI, GH, TP and Ca, respectively, but a significant rise of P after triamcinolone was found in Hypo and Eu subgroup. When comparing the subgroups according to thyroid function, only mild differences could be demonstrated in BS pattern both during IVGTT and TIVGTT, but significant differences of KGt and KGi were found between Eu and Hypo subgroups. No differences were observed in patterns of IRI, GH and Ca (except fasting values in Eu and Hypo subgroups during IVGTT, but significant differences were found in the pattern of P and particularly of TP. Except of differences of TP and P, changes during TIVGTT were not more pronounced than those during IVGTT. The comparison of effects of triamcinolone pretreatment on IVGTT and on OGTT (as were described previously) demonstrated similar effects of triamcinolone in Eu subgroups (significant changes of BS, IRI and P), but different action in Hypo- and Tx subgroups (where the significant changes of BS, IRI and P during OGTT and IVGTT were not parallel). These findings may suggest a possible role of some gastrointestinal and/or hepatic factors in action of triamcinolone in impaired thyroid function, but not in normal persons.

Adult↗
PubMed1980

[Effect of thyrotoxicosis on adrenergic receptors, cyclic adenosine monophosphate, glycogen and enzymes of the myocardium].

In the heart the interaction of the thyroid hormones, the catecholamines and the effect of the beta-blocker was studied. The binding of the radioactive noradrenalin (3H-NA) was higher in the particles of the thyreotoxic myocardium of the dog got by centrifugation at 1,000 and 78,000 g. The 3H-NA-binding was inhibited with propranolol, isoprenalin and in lower concentrations with trimepranol in dogs and also in rats. In the myocardium of the thyreotoxic dogs 3H-NA was less superseded with isoprenalin, in the myocardium of thyreotoxic rats less with non-active norarenalin in comparison to euthyroid animals. The thyreotoxicosis caused an increase of the activities of phosphorylase, of the lipases, of the calcium-dependent ATPase, the protein kinase in presence of histone, further a decrease of the activity of adenyl cyclase, particularly in presence of sodium fluoride and a decrease of the concentration of the cyclic adenosine monophosphate in the myocardium of the rats and dogs, respectively. The pharmacological thyreotoxicosis decreased the concentration of the heart glycogen. This decrease was inhibited by the beta-blocker trimepranol, but not by the alpha-blocker phentolamine. Three possibilities of the explanation of the findings of this complex study are cited. The influence of the thyroid hormones and beta-blockers 1. on the transport and calcium metabolism, 2. on the synthesis of the heart proteins, 3. on the backbinding control of the hormonal effect at cellular level.

Animals↗
PubMed1980

Effect of theophylline on binding of cortisol to cytosolic receptors of human leukocytes.

In the cytosol of human leukocytes effect of theophylline on cortisol binding was investigated by charcoal-dextran assay. The presence of theophylline enhances the rate of binding of [3H] cortisol to the receptor and increases its apparent affinity for the steroid. A high affinity (apparent association constants: without theophylline KA = 0.10 x 10(10) 1 . mol-1 and with Ka = 0.14 x 10(10) 1 . mol-1) and low capacity (number of binding sites was for both examples practically the same N = 2.7 f mol . mg-1 of protein) of binding sites for cortisol were found.

Cytosol↗