Center of Advanced Study, Department of Zoology, Banaras Hindu University, Varanasi 221005, India.
Gen Comp Endocrinol. 2010 May 1;166(3):504-12. doi: 10.1016/j.ygcen.2010.02.020. Epub 2010 Feb 23.
In the present investigation, in vitro effects of vasotocin (VT) on oocyte (follicular) hydration during germinal vesicle breakdown (GVBD) and ovulation were demonstrated in hCG-primed and non-primed catfish. The data were compared with that of groups incubated with isotocin, and hCG alone or in combination with VT. The priming with hCG resulted in significant increases on percentage GVBD and ovulation, and stimulated follicular hydration, as judged by the increase in diameter, volume, water content, osmolality and Ca(2+) concentration. However, Na(+), K(+) ATPase activity, and concentrations of Na(+), K(+) and Mg(2+) did not alter significantly. The incubations with hCG or VT stimulated all the above parameters. In the non-primed fish, the response of hCG was significantly higher on follicular diameter, volume and osmolality, and that of VT on ovulation. In the primed fish, the VT response was significantly higher on GVBD, ovulation, Na(+), K(+) ATPase activity and divalent cation concentrations. The co-incubation with both hCG and VT produced maximal increases in all the parameters with significantly higher effects in the primed fish. The effects of IT on various parameters were relatively low compared to hCG or VT effects. The results indicate that VT may play an important role in oocyte (follicular) hydration, which is consistent with its role in osmoregulation of fish.
在本研究中，我们在已注射 hCG 和未注射 hCG 的鲶鱼中，证明了血管加压素（VT）在卵母细胞（卵泡）在生发泡破裂（GVBD）和排卵时水合作用中的体外作用。将这些数据与用缩宫素（OT）、hCG 单独或与 VT 联合孵育的组的数据进行了比较。hCG 的预处理导致 GVBD 和排卵的百分比显著增加，并通过直径、体积、水含量、渗透压和 Ca(2+)浓度的增加来判断卵泡水合作用得到刺激。然而，Na(+)、K(+)ATP 酶活性以及 Na(+)、K(+)和 Mg(2+)的浓度没有显著改变。hCG 或 VT 的孵育刺激了所有上述参数。在未预处理的鱼中，hCG 对卵泡直径、体积和渗透压的反应显著更高，而 VT 对排卵的反应更高。在预处理的鱼中，VT 对 GVBD、排卵、Na(+)、K(+)ATP 酶活性和二价阳离子浓度的反应显著更高。hCG 和 VT 的共同孵育可使所有参数最大程度增加，并且在预处理的鱼中效果更显著。与 hCG 或 VT 相比，OT 对各种参数的作用相对较低。这些结果表明，VT 可能在卵母细胞（卵泡）水合作用中发挥重要作用，这与其在鱼类渗透压调节中的作用一致。
