Effects of iodotyrosines, thyronines, iodothyroacetic acids and thyromimetic analogues on in vitro copper-induced oxidation of low-density lipoproteins.

We studied the effect of different thyroid compounds [(I2, monoiodo-L-tyrosine (MIT), diiodo-L-tyrosine (DIT), L-thyronine (T0), 3,5-diiodo-L-thyronine (T2), 3,5,3'-triiodo-L-thyronine (T3), 3,3',5'-triiodo-L-thyronine (rT3), 3,5,3',5'-tetraiodo-L-thyronine (T4), 3,5-diiodothyroacetic acid (TA2), 3,5,3'-triiodothyroacetic acid (TA3) and 3,5,3',5'-tetraiodothyroacetic acid (TA4)] or thyromimetics [(3,5-dimethyl-3'-isopropyl-L-thyronine (DIMIT) and 3,5-diiodo-3'-isopropyl-thyroacetic acid (IpTA2)] on in vitro copper-induced oxidation of low-density lipoproteins (LDL). Human native LDL (0.05 g protein/L) oxidation was induced by 2.

Influence of prolonged fasting and thyroid hormone on the alpha 2-adrenergic response in isolated epididymal adipocytes of Wistar rats.

Fasting and thyroid hormone have been reported to modulate the beta-adrenergic pathway of lipolysis in rat, but their effects on the alpha 2-adrenergic response are not well known. The purpose of the present study was to investigate this point. Male Wistar rats, 3 weeks old, were thyroidectomized surgically, kept for 1 month at 25 degrees C and then fasted or not fasted for 3 days with or without daily intraperitoneal injection of 3,5,3'-tri-iodo-L-thyronine (T3; 4.

Influence of prolonged fasting on thyroid hormone modulation of lipolysis in isolated epididymal adipocytes of Wistar rats.

Male Wistar rats, 3 weeks old, were thyroidectomized surgically, kept for 1 month at 25 degrees C and then fasted for 3 days, with or without daily intraperitoneal injection of 3,5,3'-triiodo-L-thyronine (4.6 nmol T3/100 g body weight). Age-matched fed euthyroid rats were used as controls.

Changes in thyroid hormone and thyrotrophin in the serum and thyroid glands of developing genetically obese male and female Zucker rats.

In a first experiment, serum thyroxine (T4), 3,5,3'-triiodothyronine (T3) and thyrotrophin (TSH) concentrations as well as thyroid gland T4 and T3 contents were measured in developing lean and obese Zucker male and female rats of 4-16 weeks of age. The rats were bred in our laboratory and always treated in sex-matched pairs of one lean and one obese rat from the same litter. Serum T4 was not different in any phenotype/sex group at 4 weeks.

Relations between reperfusion arrhythmias and myocardial norepinephrine and accumulation of calcium in the rat.

The relation between myocardial norepinephrine and reperfusion arrhythmias was examined in isolated rat hearts. The influence of pre-treatment with reserpine on the incidence of reperfusion arrhythmias and on the accumulation of calcium in the myocardium during ischemia and reperfusion was also studied. Ischemia was induced by ligation of the coronary artery and, in some experiments, the cardiac stores of norepinephrine were labeled with 3H-norepinephrine.