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. 1975 Sep;150(3):489–493. doi: 10.1042/bj1500489

Conversion of thyroxine into tri-iodothyronine by rat liver homogenate.

PMCID: PMC1165764  PMID: 174547

Abstract

By using a highly specific radioimmunoassay the formation of tri-iodothyronine by the deiodination of thyroxine was studied in rat liver homogenate. Several observations suggest that the reaction observed is enzymic in nature. Pre-heating the homogenate for 30 min at 56 degrees C completely abolished conversion of thyroxine into tri-iodothyronine; the component of rat liver homogenate responsible could be saturated with substrate; iodotyrosines displayed competitive activity. Between 0 degrees and 37 degrees C, the tri-iodothyronine-production rate was positively correlated with incubation temperature. The addition of NAD+ enhanced conversion into tri-iodothyronine, which suggests that an oxidative mechanism is involved. 5-Propyl-2-thiouracil and 6-propyl-2-thiouracil, both known to prevent deiodination in vivo, greatly decreased the deiodiantion activity of rat liver homogenate.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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