Kang H G, Jeong D H, Yang J J, Lee B K, Kong J K, Lee J W, Kim I H
College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea.
Reprod Domest Anim. 2015 Feb;50(1):149-58. doi: 10.1111/rda.12470. Epub 2014 Dec 17.
This study evaluated the structural changes in the reproductive tract of Asiatic black bears using serial transrectal ultrasonography. In addition, the ultrasonographic observations were compared with the results of vaginal cytology and hormonal analyses. The collection of blood for hormonal analysis, vaginal cytology and transrectal ultrasonography was performed in two bears (Bears 1 and 2) from June 2011 to August 2013 without mating and in a third bear (Bear 3) from April to December 2012, allowing natural mating. Serial ultrasonographic observations showed cyclic changes in ovarian structures (e.g. emergence of small follicles, growth and ovulation of dominant follicles and corpus luteum (CL) formation) during the reproductive cycles of the three bears. The diameter of the uterine horns remained similar throughout the reproductive cycle in Bears 1 and 2, and it remained similar from April until October, but an enlargement containing foetuses was observed in Bear 3 in December. The ultrasonographic observations were consistent with the data obtained through vaginal cytology and progesterone analysis during the reproductive cycle. An average of 4.0 (±0.4) dominant follicles was observed during the oestrous stage (May-August), during which the superficial cells accounted for >90% of the total vaginal cells. In addition, the detection of an average of 2.6 (±0.2) CL was associated with increased plasma progesterone concentrations (3.0 ± 0.4 ng/ml) between June and December (near hibernation). In conclusion, serial transrectal ultrasonography demonstrated yearly oestrous (ovulation) cycles via follicular dynamics and CL formation on ovaries, accordingly with vaginal cytology and hormonal level in the Asiatic black bear.
本研究采用经直肠连续超声检查评估了亚洲黑熊生殖道的结构变化。此外，还将超声检查结果与阴道细胞学检查及激素分析结果进行了比较。对2只熊（熊1和熊2）在2011年6月至2013年8月期间未交配时进行了血液激素分析、阴道细胞学检查和经直肠超声检查，对第3只熊（熊3）在2012年4月至12月期间进行了上述检查，使其自然交配。连续超声检查显示，三只熊在生殖周期中卵巢结构出现周期性变化（如小卵泡出现、优势卵泡生长和排卵以及黄体形成）。熊1和熊2的子宫角直径在整个生殖周期中保持相似，熊3在4月至10月期间保持相似，但在12月观察到子宫角增大且怀有胎儿。超声检查结果与生殖周期中通过阴道细胞学检查和孕酮分析获得的数据一致。在发情期（5月至8月）平均观察到4.0（±0.4）个优势卵泡，在此期间，表层细胞占阴道细胞总数的90%以上。此外，在6月至12月（接近冬眠）期间，平均检测到2.6（±0.2）个黄体，同时血浆孕酮浓度升高（3.0±0.4 ng/ml）。总之，经直肠连续超声检查通过卵泡动态变化和卵巢黄体形成证明了亚洲黑熊的年度发情（排卵）周期，与阴道细胞学检查和激素水平相符。
