دورية
Thyroid hormones modulate the endocrine and autocrine/paracrine actions of leptin on thyrotropin secretion
| العنوان: | Thyroid hormones modulate the endocrine and autocrine/paracrine actions of leptin on thyrotropin secretion |
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| المؤلفون: | da Veiga, M A L Costa, de Jesus Oliveira, K, Curty, F H, de Moura, C C Pazos |
| المصدر: | Journal of Endocrinology; July 2004, Vol. 183 Issue: 1 p243-247, 5p |
| مستخلص: | We investigated the influence of hypo- and hyperthyroidism on the ability of leptin to modulate TSH secretion. Two hours after receiving leptin (8 μg leptin/100 g BW; s.c.), hyperthyroid rats (10 μg thyroxine (T4)/100 g body weight (BW) for 5 days) showed a 1.7-fold increase in serum TSH (P<0.05); in hypothyroid rats, leptin had no effect. Hemi-pituitaries of hyperthyroid rats incubated with 10−9and 10−7M leptin showed reductions in TSH release of 40 and 50% respectively (P<0.05); incubation with 1:2000 and 1:500 dilutions of antiserum against leptin resulted in 3- and 4-fold higher TSH release (P<0.05 and P<0.001 respectively). However, in hypothyroid pituitaries leptin or the antiserum had no effect. The results suggest that the in vivoand in vitroresponsiveness of TSH to leptin is abolished in hypothyroidism and is preserved in short-term hyperthyroidism, in comparison to previous reports in euthyroidism. In addition, the inhibitory action of pituitary leptin is enhanced in hyperthyroid glands, which may suggest a role for locally produced leptin in the suppression of TSH release associated with hyperthyroidism. |
| قاعدة البيانات: | Supplemental Index |
| تدمد: | 00220795 14796805 |
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| DOI: | 10.1677/joe.1.05746 |