Independence of ovarian masculinization and hypothyroidism in frog tadpoles after methimazole treatment.
Independence of ovarian masculinization and hypothyroidism in frog tadpoles after methimazole treatment.
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甲硫咪唑治疗后青蛙蝌蚪卵巢雄性化和甲状腺功能减退的独立性。
DOI：
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发表时间：
1974
期刊：
影响因子：
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通讯作者：
H. Liang
中科院分区：
文献类型：
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作者：
C. Hsü;H. Huang;C. Chang;H. Liang
这项工作旨在澄清甲硫咪唑诱导的蝌蚪卵巢性别转变是否如一些作者所认为的那样是由于该药物的致甲状腺肿特性所致。将完整的、甲状腺切除的和垂体切除的林蛙雌性蝌蚪在0.005%甲硫咪唑溶液中饲养作为实验；自来水中的三个平行组作为对照。经过四个月的致甲状腺肿素治疗后，所有六组蝌蚪均被处死，并对其性腺进行组织学性别鉴定。结果表明，自来水中的完整、甲状腺切除和垂体切除的蝌蚪具有正常的卵巢，而甲巯咪唑溶液中的完整、甲状腺切除和垂体切除的动物的卵巢都至少部分转化为睾丸，在某些情况下，几乎完全转化为睾丸。从组织学角度来看，甲硫咪唑处理引起的性别转变过程与热处理蝌蚪或自发性逆转中观察到的性别转变过程没有什么不同。这些发现表明，垂体和甲状腺不参与致甲状腺肿素诱导的性别转变。这提供了额外的证据来支持我们的信念，即各种因素，如热、性激素、基因作用和致甲状腺肿素，尽管本身截然不同，但都会对卵巢产生直接和有害的影响，触发从破坏卵母细胞到诱导网状细胞的共同途径，最终导致性别转变。
This work aims to clarify whether methimazole-induced sex transformation in tadpole ovaries is due to the goitrogenic property of the drug as some authors have suggested. Intact, thyroidectomized, and hypophysectomized female tadpoles of Rana catesbeiana were reared in 0.005% methimazole solution as experimentals; three parallel groups in tap water served as controls. After four months of goitrogen treatment, all six groups of tadpoles were sacrificed and their gonads sexed histologically. The results showed that intact, thyroidectomized, and hypophysectomized tadpoles in tap water had normal ovaries, while ovaries of intact, thyroidectomized, and hypophysectomized animals in methimazole solution were all transformed at least partially, and in some cases, almost completely to testes. Histologically, the process of sex transformation resulting from methimazole treatment was not different from that observed in heat-treated tadpoles or in spontaneous sex reversals. These findings demonstrate that the hypophysis and thyroid were not involved in goitrogen-induced sex transformation. This provides additional evidence in support of our belief that various factors, such as heat, sex hormones, gene action, and goitrogens though diametrically different per se, all deliver a direct and detrimental effect on the ovary, triggering a common pathway from destruction of oocytes to induction of rete cells which results ultimately in sex transformation.