Radford H M, Panaretto B A, Avenell J A, Turnbull K E
CSIRO, Division of Animal Production, Blacktown, New South Wales, Australia.
J Reprod Fertil. 1987 Jul;80(2):383-93. doi: 10.1530/jrf.0.0800383.
The 24 h i.v. infusion of Merino ewes with 60 or 100 microgram mouse epidermal growth factor (EGF)/kg body weight on Days 4, 9 or 14 of the oestrous cycle decreased the strength of wool attachment and caused marked changes in subsequent reproductive performance. In ovaries removed 2 days after EGF treatment all follicles greater than or equal to 0.6 mm diameter were atretic. After 7 days either a normal pattern of atresia or no atresia was evident while after 12 days the pattern of follicular atresia was similar to that in controls. Irrespective of stage of cycle EGF caused dose-dependent increases in plasma FSH concentrations that persisted for up to 14 days. Changes in plasma LH concentrations were generally similar after infusion on Days 4 and 14, but were smaller and shorter-lived after infusion on Day 9. Irrespective of dose, the infusion of EGF on Days 4 and 14 caused immediate luteolysis then the formation of a luteinized follicle in many ewes. Most ewes treated on Day 4 returned to oestrus between Days 17 and 21 with the same ovulation rate (1.3) as the controls. Of those infused on Day 14 oestrus occurred about a cycle length later than expected and their ovulation rate then (1.9) was also similar to that of the controls (1.7). Luteal function was not affected in ewes infused on Day 9, and most returned to oestrus between Days 17 and 20 with an ovulation rate of 3.2. Fertile rams were not placed with the ewes until after the differences in ovulation rate had been observed. Mating occurred generally 2-4 weeks after treatment, and there were no differences between EGF-treated and control ewes in fertility or fecundity. The results are interpreted as indicating that mouse EGF induces ovarian follicular atresia but has differential effects on luteal function according to the stage of the oestrous cycle at which it is given. As a consequence of these two effects, which lead to differential changes in gonadotrophin secretion, ovarian function may be temporarily impaired, little affected or improved.
在发情周期的第4、9或14天，给美利奴母羊静脉输注24小时，剂量为60或100微克小鼠表皮生长因子（EGF）/千克体重，会降低羊毛附着强度，并导致随后的繁殖性能发生显著变化。在EGF处理后2天切除的卵巢中，所有直径大于或等于0.6毫米的卵泡都发生了闭锁。7天后，要么出现正常的闭锁模式，要么没有闭锁现象，而12天后，卵泡闭锁模式与对照组相似。无论周期阶段如何，EGF都会导致血浆促卵泡素（FSH）浓度呈剂量依赖性增加，这种增加可持续长达14天。在第4天和第14天输注后，血浆促黄体素（LH）浓度的变化通常相似，但在第9天输注后变化较小且持续时间较短。无论剂量如何，在第4天和第14天输注EGF都会立即导致黄体溶解，然后在许多母羊中形成黄体化卵泡。在第4天接受治疗的大多数母羊在第17至21天之间恢复发情，排卵率（1.3）与对照组相同。在第14天接受输注的母羊中，发情发生时间比预期晚约一个周期长度，此时它们的排卵率（1.9）也与对照组（1.7）相似。在第9天接受输注的母羊黄体功能未受影响，大多数在第17至20天之间恢复发情，排卵率为3.2。直到观察到排卵率差异后，才将可育公羊与母羊放在一起。交配通常在治疗后2至4周进行，EGF处理的母羊和对照母羊在生育力或繁殖力方面没有差异。这些结果被解释为表明小鼠EGF诱导卵巢卵泡闭锁，但根据给药时发情周期的阶段对黄体功能有不同影响。由于这两种效应导致促性腺激素分泌的差异变化，卵巢功能可能会暂时受损、影响不大或得到改善。
