Singh U P, Krishna A, Bhatnagar Kunwar P
Department of Zoology, Banaras Hindu University, Varanasi, India.
Acta Biol Hung. 2002;53(3):267-78. doi: 10.1556/ABiol.53.2002.3.3.
The present study was designed to investigate changes in thyroid activity during the reproductive cycle in Taphozous longimanus. Thyroid gland showed marked seasonal variation in weight and secretory activity. It was inactive in quiescence and early to mid-winter dormancy and active during recrudescence and breeding period during late winter dormancy. The serum 3,5,3'-triiodothyronine (T3) and thyroxine (T4) concentrations showed significant variation and closely coincided with thyroid activity. The T3 and T4 concentrations were higher in recrudescence, late winter dormancy and minimum in quiescence and initial stages of first pregnancy. The body weight (r = 0.56), ovary weight (r = 0.73), and thyroid weight (r = 0.70) showed correlation with each other and with T3 and T4 concentrations. The correlation between body weight, thyroid weight and T3 and T4 concentrations in non-pregnant bats was higher when compared with pregnant bats. The T3 and T4 levels remained low during the initial stages of development in first pregnancy when compared with the initial stages of second pregnancy. The scant food supply and low levels of T3 and T4 and low temperature during initial stages of first pregnancy might be responsible for differential rate of fetal development in two successive pregnancies in T. longimanus.
本研究旨在调查长翼蝠生殖周期中甲状腺活动的变化。甲状腺在重量和分泌活动方面表现出明显的季节性变化。在静止期和冬初至冬中休眠期不活跃，而在冬末休眠期的复苏期和繁殖期活跃。血清3,5,3'-三碘甲状腺原氨酸（T3）和甲状腺素（T4）浓度有显著变化，且与甲状腺活动密切相关。T3和T4浓度在复苏期、冬末休眠期较高，在静止期和首次怀孕初期最低。体重（r = 0.56）、卵巢重量（r = 0.73）和甲状腺重量（r = 0.70）相互之间以及与T3和T4浓度均呈相关性。与怀孕蝙蝠相比，非怀孕蝙蝠的体重、甲状腺重量与T3和T4浓度之间的相关性更高。与第二次怀孕初期相比，首次怀孕初期发育阶段的T3和T4水平较低。首次怀孕初期食物供应不足、T3和T4水平低以及温度低可能是长翼蝠连续两次怀孕胎儿发育速度不同的原因。
