Failure of cryptorchidism to suppress fertility in a tropical rodent.
Failure of cryptorchidism to suppress fertility in a tropical rodent.
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隐睾无法抑制热带啮齿动物的生育能力。
DOI：
10.1095/biolreprod48.6.1354
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发表时间：
1993
影响因子：
3.6
通讯作者：
Heideman,PD
中科院分区：
文献类型：
--
作者：
Bronson,FH;Heideman,PD
甘蔗鼠（Zygodontomys brevicauda）全年都在委内瑞拉炎热的大草原上繁殖，只有赤道以上8°。该物种的男性对热的生殖反应进行了比较的温度区啮齿动物，白足鼠（Peromyscus leucopus）。当在不同的环境温度下测试时，睾丸相对于阴囊的运动在两个物种中是相似的，但甘蔗小鼠的睾丸被证明对维持核心体温更具抵抗力。在两个实验中，隐睾甘蔗小鼠经历了只有24%和5%的睾丸重量下降，几乎所有这些男性表现出正常的精子发生和精子储存。相比之下，隐睾白足小鼠睾丸重量下降58%，精子发生完全抑制，所有雄性小鼠完全或几乎没有储存精子。交配试验表明，甘蔗小鼠确实保持生育能力至少2至3个月后，使隐睾。当与雌性配对时，这些雄性的正常数量产下正常窝仔。值得注意的是，甘蔗鼠睾丸对热的相对不敏感性实际上可能比我们目前的观点更能代表阴囊哺乳动物，我们目前的观点是基于对来自凉爽气候而不是大多数哺乳动物生活的热带的人类和哺乳动物的研究。
The cane mouse (Zygodontomys brevicauda) breeds year-round on the hot llanos of Venezuela, only 8°above the equator. The reproductive responses of the males of this species to heat were compared with those of a temperature zone rodent, the white-footed mouse (Peromyscus leucopus). When tested at different ambient temperatures, the movement of the testis in relation to the scrotum was similar in the two species, but the cane mouse’s testis proved to be much more resistant to maintenance at core body temperature. In two experiments, cryptorchid cane mice experienced only a 24% and a 5% decrease in testis weight, and almost all of these males showed normal spermatogenesis and sperm storage. In comparison, cryptorchid white-footed mice showed a 58% drop in testis weight, a total inhibition of spermatogenesis, and a complete or near absence of stored sperm in all males. A mating test demonstrated that cane mice indeed remain fertile for at least 2 to 3 mo after being rendered cryptorchid. Normal numbers of these males when paired with females fathered normal litters. It is noted that the relative insensitivity of the testis of the cane mouse to heat might actually be more representative of scrotal mammals in general than is suggested by our present perspective, which has been developed on the basis of study of humans and mammals from cool climates rather than the tropics, where most mammals live.