Verma Sushant Kumar, Alim Abdul
Co-operative College (Ranchi University), Jharkhand, India.
Co-operative College (Ranchi University), Jharkhand, India.
Anim Reprod Sci. 2015 May;156:111-7. doi: 10.1016/j.anireprosci.2015.03.007. Epub 2015 Mar 19.
The present study was carried out to analyze the differences in the activity of ultimobranchial gland (UBG) between male and female fresh water teleost Mastacembelus armatus during reproductive cycle. Considerable variations in the nuclear diameter of UBG cells and plasma calcitonin (CT) levels during different reproductive phases of testicular and ovarian cycle suggested that the activity of the UBG depends upon the sexual maturity of fishes. A positive correlation was observed between plasma CT and sex steroid levels and the gonadosomatic index in both sexes which further confirmed the involvement of UBG in the processes related to gonadal development in fishes irrespective of the sex. Sudden increase in the level of plasma CT and nuclear diameter of UBG cells after administration of 17 α-methyltestosterone in males and 17 β-estradiol in females during resting phase of the reproductive cycle clearly showed that UBG becomes hyperactive with increases in the level of sex steroids. Plasma calcium level was also found to be positively correlated with gonadal maturation in females. However no such change in plasma calcium level in relation to testicular cycle was observed. Thus it can be concluded that UBG becomes hyperactive during gonadal maturation but its role differs between male and female fishes. In females it may involved in both gonadal maturation and plasma calcium regulation while in males its involvement in calcium regulation was not justified. Variations in the level of CT during various phases of testicular cycle evidenced its involvement in gonadal maturation only.
本研究旨在分析淡水硬骨鱼纹胸鮡在生殖周期中雌雄两性鳃后腺（UBG）活性的差异。在睾丸和卵巢周期的不同生殖阶段，UBG细胞的核直径和血浆降钙素（CT）水平存在显著差异，这表明UBG的活性取决于鱼类的性成熟度。在两性中，血浆CT与性类固醇水平以及性腺指数之间均观察到正相关，这进一步证实了无论性别如何，UBG均参与鱼类性腺发育相关过程。在生殖周期的静止期，给雄性注射17α-甲基睾酮、雌性注射17β-雌二醇后，血浆CT水平和UBG细胞的核直径突然增加，这清楚地表明UBG随着性类固醇水平的升高而变得活跃。还发现雌性血浆钙水平与性腺成熟呈正相关。然而，未观察到与睾丸周期相关的血浆钙水平变化。因此可以得出结论，UBG在性腺成熟期间变得活跃，但其在雄性和雌性鱼类中的作用有所不同。在雌性中，它可能参与性腺成熟和血浆钙调节，而在雄性中，其参与钙调节的情况并不明确。睾丸周期各阶段CT水平的变化证明其仅参与性腺成熟。
