摘要
本实验选用性成熟的京白种蛋鸡,从同一产蛋顺序中取其发育不同阶段的各级卵泡(F_1～F_4),分离膜层,消化为单个的膜细胞,进行短期细胞培养,着重观察鸡促性腺激素释放激素(GnRH)对培养过程中膜细胞雌二醇分泌的影响.用放射免疫法测定细胞培养液中雌二醇的含量,得到以下结果:①未加外源激素处理的对照组细胞,随着卵泡从小到大的发育成熟过程,膜细胞雌二醇的分泌量逐渐降低;②适当剂量的鸡 GnRH-Ⅱ对各级卵泡膜细胞雌二醇的分泌均有促进作用,其中 F_4,F_3,F_2比 F_1更敏感;③加前体物(孕酮或雄烯二酮)之后,再加鸡 GnRH-Ⅱ比单加前体物或单加鸡 GnRH-Ⅱ,膜细胞雌二醇的分泌量增加更明显.实验结果提示,在体外细胞培养的条件下,GnRH-Ⅱ对膜细胞雌二醇的分泌不仅有促进作用,还可能促进雌二醇的合成。
In order to determine if GnRH could directly affect estradiol(E_2)secretion by the theca cells of avian follicles,laying hens(Beijing white-Leghorn strain)were killed 1～3 hours before the ex- pected time of ovulation at the beginning of a laying cycle.Theca layers of follicles(F_4-F_1)were isolated from the follicle walls and digested by trypsin.The theca cells(1×10~6)were incubated in 1 mL of medium 199 containing chicken GnRH-Ⅱ(5～500ng),and adding progesterone or androstenedione for 3 hours at 37℃.The media were collected respectively for measuring E_2 by radioimmunoassay.The following results were obtained:①The amounts of estradiol secreted from the theca cells gradually decreased with the maturation from F_4to F_1 in the control group without exogenous hormones;②Appropriate doses(50～ 500ng)of GnRH-Ⅱ were capable of accumulating the secretion of E2 from theca cells of the hierarchical follicles F_4～F_2,and no GnRH-Ⅱ effect on F_1 was seen;③The efffect of GnRH-Ⅱ was more obvious in combination with two precursors,progesterone and androstenedione,than that of GnRH-Ⅱ alone, showing that GnRH-Ⅱ were also capable of stimulating the synthesis of E_2.
关键词
GNRH
卵泡膜细胞
雌二醇
鸡
GnRH
theca cells of follicles
estradiol
chicken
