Sexual maturation in female rats: Hereditary, developmental and environmental aspects

  title={Sexual maturation in female rats: Hereditary, developmental and environmental aspects},
  author={Robert W. Rivest},
  • R. Rivest
  • Published 15 October 1991
  • Biology
  • Experientia
Two physiological components of sexual maturation, vaginal opening and first estrus, apparently evolve similarly in Wistar and Sprague-Dawley rats. However, a bimodal distribution in the frequency of the days of vaginal opening is observed within a given strain, which is less related to heredity than to the timing and type of experiment. In addition, when the modulators of sexual maturation are reviewed, it can be observed that sensitivity to external stimuli can vary even within a strain. For… 
Minor involvement of somatic growth in the onset of puberty of Hatano high- and low-avoidance rats.
There is a phenotypic difference in the timing of female puberty in Hatano rats exhibiting a different timing of ovarian development in response to gonadotropin, indicating that postnatal somatic growth is not the predominant determinant in the onset of puberty inHatano rats.
Neonatal exposure to genistein affects reproductive physiology and behavior in female and male Long-Evans rats
It was found that neonatal exposure to genistein did not affect puberty onset in female or male rats, however, female rats exposed toGenistein displayed significantly more irregular estrous cycles than controls, which altered the development of male copulatory behavior.
Differential Growth of the Reproductive Organs during the Peripubertal Period in Male Rats
The present study evaluated the maturation of male rat accessory sex organs during the peripubertal period using tissue weight measurement, histological analysis and RT-PCR assay, suggesting the activation of hypothalamic GnRH pulse-generator before puberty onset.
Exposure to methylphenidate during peri-adolescence affects endocrine functioning and sexual behavior in female Long–Evans rats
Differences in the estrous cycles of Goto-Kakizaki and Wistar rats
Delays in proceeding from proestrus to estrus could reflect a dysregulation of the hypothalamic-pituitary-gonadal axis, accompanying progression of the diabetic condition, and cause anovulatory cycles, which could explain the reduced reproductive capacity of Goto-Kakizaki rats.
Gender dimorphic effects of voluntary running in laboratory rats depends on maturational status
A temporary decline in food intake and a lasting decrease in body weight occurred for active male rats in comparison to their sedentary controls, and wheel access facilitated food intakeand preserved body weight gain in female rats in compared to their Sedentary counterparts.
Perinatal Testosterone Contributes to Mid-to-Post Pubertal Sex Differences in Risk for Binge Eating in Male and Female Rats
Examination of animal data is significant in suggesting that perinatal testosterone exposure may protect against binge eating and underlie sex differences in binge eating prevalence during and after puberty.


The effect of light on a polyestrous mammal was investigated and it was found that the normal diurnal variations associated with estrus in the rat were reversed when the day-night rhythm of light was artificially shifted.
Social factors and puberty in female rats.
The results do not support the view that in the rat pheromones from adult males enhance puberty in females, contrary to what is known to happen in the mouse.
Age at puberty and first litter size in early and late paired rats.
It was found that females of this strain differ from at least one other strain of laboratory rat in that neither age at vaginal perforation nor age at first estrus was affected in Sprague-Dawley females by the presence or absence of male, regardless of his age or breeding history.
First Estrus in Rats in Relation to Age, Weight, and Length.∗
The experiments here reported represent an attempt to determine whether a relation exists between the growth rate and first estrus in the rat and whether this relation exists by limiting the size of the nursing litter to 5 or 6 animals.
Time factor in ovulation blockade in rats under differing lighting conditions.
Compared with the locally inbred Osborne-Mendel rats, CD rats show a longer “critical period,” beginning before 13:30 and lasting beyond 17:00 (Endocrinology 80: 790, 1967), and Pentobarbital sodium was injected during the afternoon of the day of proestrus.
Relationship between pubertal timing and body size in underfed male rats.
Underfed rats are more sexually mature than normally fed controls of the same weight despite having a lower percentage of body fat, and the critical body weight or critical body fat hypotheses of puberty in male rats do not support.
Changes in adrenocortical function precede the onset of persistent estrus in rats exposed to constant light before puberty.
  • J. Ramaley
  • Biology, Psychology
    Biology of reproduction
  • 1977
It appears that changes in adrenocortical function precede the loss of ovulatory cycles in both LL-reared groups and that changes (elevated basal corticosterone and a prolonged stress response) emerge earlier in the S-LL groups which developed persistent estrus earlier.
Hormonal changes in the immature rat after administration of pregnant mare serum gonadotrophin: influence of body weight.
We have shown previously that pregnant mare serum gonadotrophin (PMSG) induces ovulation only in rats weighing over 60 g on the day of injection. The under-60 g rats do not ovulate although they
Puberty in the rat: modulation by melatonin and light.
Endogenous melatonin rhythms are modified by the lighting environment, and results obtained with exogenousmelatonin suggest that they could be one of the factors controlling timing of sexual maturation.
Exteroceptive Factors, Sexual Maturation and Reproduction in the Female Rat
In 2 of 3 experiments females kept singly after weaning reached sexual maturity significantly earlier than did grouped females and the reproductive performance of females mated at 1st oestrus was not significantly different from that of older primiparae.