INDUCTION OF PERSISTENT DIESTRUS FOLLOWED BY PERSISTENT ESTRUS IS INDICATIVE OF DELAYED MATURATION OF TONIC GONADOTROPIN-RELEASING SYSTEMS IN RATS
INDUCTION OF PERSISTENT DIESTRUS FOLLOWED BY PERSISTENT ESTRUS IS INDICATIVE OF DELAYED MATURATION OF TONIC GONADOTROPIN-RELEASING SYSTEMS IN RATS
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DOI：
10.1095/biolreprod40.1.96
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发表时间：
1989-01-01
影响因子：
3.6
通讯作者：
HAYASHI, S
中科院分区：
文献类型：
--
作者：
AIHARA, M;HAYASHI, S
The relationship between the amount and duration of administration of estradiol benzoate (EB) to newborn females rats and the induction of sterility was examined in 407 animals. Vaginal smear patterns were classified into 3 types according to the incidence of vaginal proestrus and estrus over a 10-day period: persistent estrous (PE), persistent diestrous (PD), and intermediate (INT), so that the changes in vaginal smear patterns could be analysed quantitatively. Incidence of the PE pattern was most frequent in the rats that received a single injection of 10 .mu.g EB on the day of birth (Day 1). Almost all the animals receiving 10 daily injection 10 .mu.g EB from Day 1 showed persistent diestrus until at least 100 days of age. In the rats that were given 5 daily injections of 10 .mu.g EB from Day 1 through Day 5, or a single injection of 100 .mu.g EB on Day 3, the incidence of the PD pattern wa high at 41-60 days of age, but later the PD-type was replaced by the PE pattern of vaginal smears. In the rats that were treated with 5 daily injections of 10 .mu.g EB from Day 1 through Day 5 and were ovariectomized on Day 22, a slight but significant increase in the level of luteinizing hormone in plasma wasnoted after administration of EB and progesterone on Day 100 but not on DAy 50. These results indicate that neonatal injections of EB induce sterility, but the effects in dependent on the amount of EB injected and length of time over which the injections are given. It appears that an optimal dose of EB delays the maturation of the hypothalamic gonadotropin-releasing systems so that, in some cases, persistent estrus follows persistent diestrus.
