| Autor: |
Yoshida, Katsumi, Suzuki, Michiko, Sakurada, Toshiro, Kitaoka, Hirofumi, Kaise, Nobuko, Kaise, Kazuro, Fukazawa, Hiroshi, Nomura, Takashi, Yamamoto, Makiko, Saito, Shintaro, Yoshinaga, Kaoru |
| Zdroj: |
European Journal of Endocrinology; December 1984, Vol. 107 Issue: 4 p495-499, 5p |
| Abstrakt: |
Abstract. Monodeiodination of thyrxoine (T4) was studied in the liver, kidney and placenta of pregnant rats. Age matched female non-pregnant and pregnant Sprague-Dawley rats on the 7th, 14th, 17th and 21st days of gestation were used. The 800 × gsupernatants of tissue homogenates (protein 1 mg/tube) were incubated with 1 μg of stable T4in the presence of 5 mmdithiothreitol (DTT) at 37°C for 60 min at pH 7.5. Net triiodothyronine (T3) generation from T4in rat liver homogenates on the 7th day of gestation was significantly lower than that in the non-pregnant rat. Thereafter it increased, but values on the 14th, 17th and 21st days of gestation were not significantly different from those obtained in the non-pregnant rat. Net renal T3generation from T4on the 14th day was significantly lower than that in the non-pregnant rat. It was increased thereafter and the values at the 17th and 21st days of gestation were not significantly different from those in the non-pregnant rat. Net reverse T3(rT3) generation from T4in the placenta rose from the 14th to the 17th day and then dropped by the 21st day and the value at the 17th day was significantly higher than those at the 14th and 21st days of gestation. These results indcate that 1) both T4outer-ring monodeiodination in the pregnant rat liver and kidney, and T4inner-ring monodeiodination in the placenta show significant variation with the progress of gestation; 2) the time course of the T4outer-ring monodeiodination in pregnant rat liver and kidney is completely different from T4inner-ring monodeiodination in the placenta. |
| Databáze: |
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