甲状腺激素对小鼠胰腺蛋白质更新率的影响

Effect of thyroid hormone on the protein turnover rate of mouse pancreas

本文用参入法、双同位素法和衰减曲线法测定组织蛋白质更新率,探讨甲状腺激素对小鼠胰腺蛋白质更新率的影响。连续5天给正常成年小鼠每只注射L-甲状腺素100μg,致使参入小鼠胰腺总蛋白质的标记氨基酸显著减少,标记蛋白质中~3H/^(14)C比值下降、蛋白质更新率常数减小、半减期延长。这些结果表明,大剂量甲状腺激素处理可抑制小鼠胰腺蛋白质更新率,既减慢其合成,又减慢其降解。

The effects of thyroid hormone on the protein turnover of pancreas in mice were studied using labelled amino acid incorporation, double isotopic and labelled protein decay methods. After injection of L-thyroxine (100μg/mouse) for 5 days, the amino acid incorporation into pancreatic proteins of mice was profoundly decreased, the ratio of 3H/14C in labelled proteins and the fractional turnover rate of pancreatic proteins were also decreased, the protein half-lives being consequently prolonged. These findings suggest that large doses of thyroid hormone may reduce the turnover rate of pancreatic proteins, by inhibiting not only the synthesis but also the degradation.