The present study was undertaken to investigate the peripheral iodothyronine 5'-monodeiodination in different human and rat tissues. We studied iodothyronine 5'-monodeiodinase type I (5'-DI) activity in liver, kidney, intestine, right cardiac atrium and skeletal muscle and we compared the results with those in rat tissues. Lodothyronine 5'- monodeiodinase type II (5'-DII) activity was studied in normal and ischemic human heart and in rat normal myocardium and brain. The 5'-DI activity (fmol/min x mg protein) in liver and kidney was significantly higher (p < 0.001, ANOVA) in normal rat tissue than in human. However, no significant differences were observed in 5'-DI activity between normal and tumoral human intestine or between intestinal tissue of man and rat. 5'-DI activity in normal human skeletal muscle was significantly higher than that in rat skeletal muscle (p < 0.05). The 5'-DI activity was lower in human ischemic myocardium when compared to normal myocardium either in humans (p < 0.05) or rat (p < 0.001). The Km of 5'-DI was significantly lower in rat than in human kidney and liver (p < 0.05). We conclude that 1) 5'-DI is distributed widely among extrathyroidal human and rat tissues and 5'-DII activity is detectable both in human and rat heart; 2) 5'-DI activity in liver and kidney is lower in man than in rat; 3) 5'-DI activity in the skeletal muscle is higher in man than in the rat; 4) 5'-DI activity is decreased in tumoral tissues of human liver and kidney and in ischemic myocardium, while no significant difference was found between human and rat cardiac 5'-DII activity.
A study of iodothyronine 5'-monodeiodinase activities in normal and pathological tissues in man and their comparison with activities in rat tissues
Laura Sabatino;Giorgio Iervasi;
2000
Abstract
The present study was undertaken to investigate the peripheral iodothyronine 5'-monodeiodination in different human and rat tissues. We studied iodothyronine 5'-monodeiodinase type I (5'-DI) activity in liver, kidney, intestine, right cardiac atrium and skeletal muscle and we compared the results with those in rat tissues. Lodothyronine 5'- monodeiodinase type II (5'-DII) activity was studied in normal and ischemic human heart and in rat normal myocardium and brain. The 5'-DI activity (fmol/min x mg protein) in liver and kidney was significantly higher (p < 0.001, ANOVA) in normal rat tissue than in human. However, no significant differences were observed in 5'-DI activity between normal and tumoral human intestine or between intestinal tissue of man and rat. 5'-DI activity in normal human skeletal muscle was significantly higher than that in rat skeletal muscle (p < 0.05). The 5'-DI activity was lower in human ischemic myocardium when compared to normal myocardium either in humans (p < 0.05) or rat (p < 0.001). The Km of 5'-DI was significantly lower in rat than in human kidney and liver (p < 0.05). We conclude that 1) 5'-DI is distributed widely among extrathyroidal human and rat tissues and 5'-DII activity is detectable both in human and rat heart; 2) 5'-DI activity in liver and kidney is lower in man than in rat; 3) 5'-DI activity in the skeletal muscle is higher in man than in the rat; 4) 5'-DI activity is decreased in tumoral tissues of human liver and kidney and in ischemic myocardium, while no significant difference was found between human and rat cardiac 5'-DII activity.File | Dimensione | Formato | |
---|---|---|---|
prod_252705-doc_67840.pdf
non disponibili
Descrizione: A study of iodothyronine 5'-monodeiodinase activities in normal and pathological tissues in man and their comparison with activities in rat tissues
Dimensione
81.01 kB
Formato
Adobe PDF
|
81.01 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.