The primary objectives of this study were to follow the temporal patterns of testicular LH and FSH receptor (LH-R and FSH-R) concentrations and affinity (Ka) during sexual maturation in bulls and to see if such patterns could help explain the control of rapid testicular growth that occurs after 25 weeks of age, when serum gonadotropin concentrations are low. Separate groups of Hereford x Charolais calves (n = 6) were castrated every 4 weeks from 5 to 33 weeks of age and at 56 weeks of age. A week prior to castrations, from 5 to 33 weeks of age, blood was collected every 15 min for 10 h. The transition from indifferent supporting cells to Sertoli cells in seminiferous tubules was rapid between 13 and 25 weeks and rapid testis growth occurred after 25 weeks of age. Serum LH and FSH concentrations were transiently elevated at 12 weeks of age (P < 0.05). LH-R concentrations decreased from 13 to 25 weeks of age and increased to 56 weeks of age (P < 0.05). LH-RKa decreased from 9 to 17 weeks of age, increased to 29 weeks of age and declined to 33 weeks of age (P < 0.05). FSH-R concentrations declined from 17 to 25 weeks of age then increased to 56 weeks of age (P < 0.05). FSH-RKa increased from 17 to 25 weeks of age (P < 0.05). High concentrations of gonadotropins and their receptors may be critical to initiate testis growth postnatally and support it after 25 weeks of age in the face of low serum gonadotropin concentrations.

译文

这项研究的主要目的是跟踪公牛性成熟过程中睾丸LH和FSH受体 (lh-r和fsh-r) 浓度和亲和力 (Ka) 的时间模式,并观察这种模式是否有助于解释25周龄后睾丸快速生长的控制,当血清促性腺激素浓度较低时。从5到33周龄和56周龄,每4周对不同的Hereford x Charolais小牛 (n = 6) 进行cast割。阉割前一周,从5到33周龄,每15分钟收集一次血液,持续10小时。在13至25周之间,生精小管中从冷漠的支持细胞向Sertoli细胞的过渡迅速,并且在25周龄后睾丸迅速生长。血清LH和FSH浓度在12周龄时短暂升高 (P <0.05)。Lh-r浓度从13至25周龄降低,并增加至56周龄 (P <0.05)。Lh-rka从9周龄下降到17周龄,增加到29周龄,下降到33周龄 (P <0.05)。Fsh-r浓度从17至25周龄下降,然后增加至56周龄 (P <0.05)。Fsh-rka从17周增加到25周龄 (P <0.05)。面对低血清促性腺激素浓度,高浓度的促性腺激素及其受体对于启动出生后睾丸生长并在25周龄后支持睾丸生长可能至关重要。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录