Pancharatna K, Saidapur S K
Department of Zoology, Karnatak University, Dharwad, India.
J Morphol. 1992 Nov;214(2):123-9. doi: 10.1002/jmor.1052140202.
Ovarian follicular dynamics and fluctuations in fat body, oviducal, and liver masses were studied in captive Rana cyanophlyctis in comparison with wild-caught frogs, sampled at monthly intervals over a period of 12 months. In both the captive and wild-caught frogs first growth phase (FGP) and second growth phase (SGP) or vitellogenic oocytes were produced throughout the period examined; however, changes in ovarian and oviducal weights were less marked in the former group. In the captive frogs SGP oocyte production was reduced by 50%, and, maximum ovarian weight and SGP oocyte number were attained 2-3 months earlier than in wild-caught controls. The FGP oocyte pool in laboratory-maintained frogs, however, was comparable with that of the corresponding wild-caught frogs. Captivity caused a threefold increase in atresia and reduced the number of oocytes reaching SGP. The depletion of fat stores in fat bodies during the later phases of captivity suggests that the deposition of lipids into oocytes (for SGP) was given priority over storage in the fat bodies. The low oviducal weights of captive frogs was correlated with a reduced number of SGP oocytes, which are the source of estrogen. On the other hand, liver weight remained high, indicating adequate hepatic vitellogenin synthesis. Possible reduction in its output was not detected, possibly due to the reduced number of follicles reaching SGP. The findings indicate that stress of captivity decreases gonadotrophins and estrogen levels. Oviducal growth is reduced in captive frogs.(ABSTRACT TRUNCATED AT 250 WORDS)
对圈养的滇蛙的卵巢卵泡动态以及脂肪体、输卵管和肝脏质量的波动情况进行了研究，并与野生捕获的青蛙作比较，在12个月的时间里每月进行采样。在圈养和野生捕获的青蛙中，在整个研究期间都产生了第一生长阶段（FGP）和第二生长阶段（SGP）或卵黄生成期的卵母细胞；然而，前一组卵巢和输卵管重量的变化不太明显。在圈养青蛙中，SGP卵母细胞的产生减少了50%，并且最大卵巢重量和SGP卵母细胞数量比野生捕获的对照组提前2 - 3个月达到。然而，实验室饲养青蛙中的FGP卵母细胞库与相应的野生捕获青蛙的相当。圈养导致闭锁增加了三倍，并减少了达到SGP的卵母细胞数量。圈养后期脂肪体中脂肪储备的消耗表明，脂质向卵母细胞（用于SGP）的沉积优先于在脂肪体中的储存。圈养青蛙输卵管重量低与作为雌激素来源的SGP卵母细胞数量减少有关。另一方面，肝脏重量仍然很高，表明肝脏卵黄蛋白原合成充足。未检测到其产量可能的降低，可能是由于达到SGP的卵泡数量减少。研究结果表明，圈养应激会降低促性腺激素和雌激素水平。圈养青蛙的输卵管生长减少。（摘要截断于250字）
