Stringer B M, Wynford-Thomas D, Gomez-Morales M, Williams E D
Cell Tissue Kinet. 1986 Jan;19(1):49-56. doi: 10.1111/j.1365-2184.1986.tb00714.x.
Previous investigations have shown that thyroid incision leads to a dramatic burst of follicular cell mitotic activity in cells adjacent to the wound edge in both normal rats and rats made hypothyroid by chronic goitrogen administration. Wound-induced thyroid mitotic activity therefore, is seen in rats with either normal or supranormal levels of circulating thyrotropin (TSH). This study was designed to investigate the thyroid mitotic response to wounding in the absence of detectable levels of circulating TSH. Rats were injected with large doses of L-thyroxine twice daily to render circulating TSH undetectable. Thyroids were incised and follicular cell mitotic activity, in relation to distance from the incision, determined at 24, 48 and 72 hr after incision. A mitotic response to wounding was maintained in L-thyroxine treated rats, even though circulating TSH was undetectable. The peak of activity was at 48 hr, but was only 50% of that found in the incised normal rat thyroid. The spatial distribution of the response suggests that there are two components of the wound response in the normal thyroid, one dependent on the presence of circulating TSH, the other TSH-independent. The results are discussed in relation to current understanding of cellular growth control.
先前的研究表明，无论是正常大鼠还是通过长期给予致甲状腺肿物质而导致甲状腺功能减退的大鼠，甲状腺切口都会使伤口边缘附近的细胞中滤泡细胞有丝分裂活性急剧增加。因此，在循环促甲状腺激素（TSH）水平正常或超常的大鼠中都能观察到伤口诱导的甲状腺有丝分裂活性。本研究旨在探讨在检测不到循环TSH水平的情况下，甲状腺对创伤的有丝分裂反应。每天给大鼠注射大剂量的L-甲状腺素两次，以使循环TSH检测不到。切开甲状腺，并在切开后24、48和72小时测定与切口距离相关的滤泡细胞有丝分裂活性。即使检测不到循环TSH，L-甲状腺素处理的大鼠对创伤仍保持有丝分裂反应。活性峰值出现在48小时，但仅为正常大鼠甲状腺切开后所发现峰值的50%。这种反应的空间分布表明，正常甲状腺中伤口反应有两个组成部分，一个依赖于循环TSH的存在，另一个不依赖于TSH。结合当前对细胞生长控制的理解对结果进行了讨论。
