Effects of the thyroid hormone derivatives 3-iodothyronamine and thyronamine on rat liver oxidative capacity

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• 作者：P. Venditti^a ; ^{venditti@unina.it"" rel=""nofollow} ; G. Napolitano^a ; L. Di Stefano^a ; G. Chiellini^b ; R. Zucchi^b ; T.S. Scanlan^c ; S. Di Meo^a
• 关键词：Thyroid hormone derivatives ; O₂ consumption ; ROS production ; Mitochondria
• 刊名：Molecular and Cellular Endocrinology
• 出版年：2011
• 出版时间：20 July 2011
• 年：2011
• 卷：341
• 期：1-2
• 页码：55-62
• 全文大小：925 K

文摘

Thyronamines T₀AM and T₁AM are naturally occurring decarboxylated thyroid hormone derivatives. Their in vivo administration induces effects opposite to those induced by thyroid hormone, including lowering of body temperature. Since the mitochondrial energy-transduction apparatus is known to be a potential target of thyroid hormone and its derivatives, we investigated the in vitro effects of T₀AM and T₁AM on the rates of O₂ consumption and H₂O₂ release by rat liver mitochondria. Hypothyroid animals were used because of the low levels of endogenous thyronamines. We found that both compounds are able to reduce mitochondrial O₂ consumption and increase H₂O₂ release. The observed changes could be explained by a partial block, operated by thyronamines, at a site located near the site of action of antimycin A. This hypothesis was confirmed by the observation that thyronamines reduced the activity of Complex III where the site of antimycin action is located. Because thyronamines exerted their effects at concentrations comparable to those found in hepatic tissue, it is conceivable that they can affect in vivo mitochondrial O₂ consumption and H₂O₂ production acting as modulators of thyroid hormone action.