Brown B W, Mattner P E, Carroll P A, Hoskinson R M, Rigby R D
CSIRO, Division of Animal Production, Blacktown, NSW 2148, Australia.
J Reprod Fertil. 1995 Jan;103(1):131-5. doi: 10.1530/jrf.0.1030131.
Groups of Merino ewe lambs were immunized against GnRH either soon after birth (prepubertal) or around puberty (peripubertal) with a prototype commercial preparation and were studied over the following 2 years to determine the long-term effects on reproductive development, function and hormone concentrations. At least 60% of the GnRH-immunized ewes in either treatment group did not experience oestrus and possessed small uteri and small ovaries that lacked follicular development. Growth rates of immunized and control ewes were similar throughout the study. Compared with the increase in plasma LH and FSH concentrations with age in control ewes, the concentrations of these hormones in immunized animals were lower and remained relatively constant from 46 to 90 weeks of age. Plasma FSH concentrations were particularly suppressed in immunized ewes and were significantly (P < 0.05) lower than the control values of 61 and 90 weeks of age. LH release after injection of 1 microgram GnRH at 90 weeks of age was either absent or suppressed in immunized ewes compared with controls. The findings suggest that the lack of GnRH stimulation and consequent deprivation of gonadotrophins, early in the life of ewes, may result in some degree of permanent impairment of hypothalamic and/or pituitary function.
将美利奴母羊羔分组，在出生后不久（青春期前）或青春期前后（青春期周围）用一种商业原型制剂对其进行促性腺激素释放激素（GnRH）免疫，并在接下来的两年里进行研究，以确定对生殖发育、功能和激素浓度的长期影响。在任一治疗组中，至少60%接受GnRH免疫的母羊未出现发情，子宫和卵巢较小，且缺乏卵泡发育。在整个研究过程中，免疫母羊和对照母羊的生长速度相似。与对照母羊随着年龄增长血浆促黄体生成素（LH）和促卵泡生成素（FSH）浓度增加相比，免疫动物体内这些激素的浓度较低，并且在46至90周龄期间保持相对恒定。免疫母羊的血浆FSH浓度尤其受到抑制，且显著低于61周龄和90周龄时的对照值（P<0.05）。与对照组相比，90周龄时注射1微克GnRH后，免疫母羊的LH释放缺失或受到抑制。这些发现表明，在母羊生命早期缺乏GnRH刺激以及随之而来的促性腺激素剥夺，可能会导致下丘脑和/或垂体功能出现某种程度的永久性损害。
