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Biomedical subjects

L K Christensen

Publications and source records attributed to L K Christensen.

16 recordsLinked to original sources

Different effects of propranolol, alprenolol, sotalol, atenolol and metoprolol on serum T3 and serum rT3 in hyperthyroidism.

Serum T4, T3, rT3 and T3 resin uptake (T3 RU) were measured before and after 7 days of treatment with either propranolol, alprenolol, sotalol, atenolol or metoprolol in hyperthyroid patients. We found a significant decrease in serum T3 after propranolol, alprenolol, atenolol and metoprolol but no change in the sotalol treated group. A significant increase in rT3 was found in the propranolol and alprenolol treated groups whereas a significant fall in rT3 was found in the atenolol and metoprolol treated groups. No change was found in the sotalol treated group. The changes observed in serum T3 and in rT3 could be explained by an inhibition of the 5'deiodinase enzyme by propranolol and alprenolol and an inhibition of both the 5'deiodinase and 5 deiodinase enzymes caused by atenolol and metoprolol.

Adrenergic beta-Antagonists

Incomplete separation of radioiodinated thyroid hormones in serum using specific antibodies.

Alkaline Sephadex G-25 columns were used to separate labelled 3,5,3',5'-thyroxine, 3,5,3'-triiodothyronine, 3,3',5'-triiodothyronine and 3,3'-diiodothyronine from the serum binding proteins followed by a quantitative elution of each hormone by coupling to its respective antibody. It is shown that although these antibodies (diluted 1:1500-1:100 000) in our radioimmunoassays are highly specific they show a high degree of non-specific binding when they are used in the concentrations necessary to get a maximal recovery of the hormones in column separating experiments.

Antibody Specificity

Drug interactions with oral sulphonylurea hypoglycaemic drugs.

The effect of the oral sulphonylurea hypoglycaemic drugs may be influenced by a large number of other drugs. Some of these combinations (e.g. phenylbutazone, sulphaphenazole) may result in cases of severe hypoglycaemic collapse. Tolbutamide and chlorpropamide should never be given to a patient without a prior careful check of which medicaments are already being given. Similarly, no drug should be given to a diabetic treated with tolbutamide and chlorpropamide without consideration of the possibility of interaction phenomena.

Allopurinol