Allen W R, Mathias S, Ford M
University of Cambridge, Department of Veterinary Medicine Equine Fertility Unit, Mertoun Paddocks, Woodditton Road, Newmarket, Suffolk CB8 9BH, UK.
Reproduction. 2005 Nov;130(5):713-20. doi: 10.1530/rep.1.00696.
The gonads, both ovaries and testes, of 44 elephant fetuses weighing 0.09-112 kg (6.1-21.3 months gestation) were examined grossly and histologically. As in equids, elephant fetal gonads undergo a phase of marked growth and enlargement during the second half of gestation, which is more pronounced in ovaries than testes due to growth and antrum formation of numerous follicles in the former. Stromal cells undergo hypertrophy and transformation to form zones of interstitial cells that are associated with the enlarged follicles in the ovaries and in which the primitive seminiferous tubules are embedded in the testes. The interstitial cells have the capacity to synthesize 5alpha-dihydroprogesterone and other 5alpha-reduced progestagens from cholesterol and pregnenelone and the hypothesis is raised that these fetal gonadal progestagens may supplement significantly the progestagens secreted by the multiple large corpora lutea of pregnancy in the elephant.
对44头体重为0.09 - 112千克（妊娠6.1 - 21.3个月）的大象胎儿的性腺（包括卵巢和睾丸）进行了大体和组织学检查。与马科动物一样，大象胎儿性腺在妊娠后半期经历显著生长和增大阶段，由于卵巢中大量卵泡的生长和卵泡腔形成，这一阶段在卵巢中比在睾丸中更为明显。基质细胞肥大并转化形成间质细胞区，这些间质细胞区与卵巢中增大的卵泡相关，而原始生精小管则嵌入睾丸的间质细胞区。间质细胞能够从胆固醇和孕烯醇酮合成5α-二氢孕酮和其他5α-还原孕激素，由此提出假说，即这些胎儿性腺孕激素可能显著补充大象妊娠时多个大黄体分泌的孕激素。
