EFFECTS OF OESTRADIOL-17β, OESTRADIOL BENZOATE AND THE SYNTHETIC OESTROGEN RU 2858 ON SEXUAL DIFFERENTIATION IN THE NEONATAL FEMALE RAT

1975 ◽  
Vol 67 (3) ◽  
pp. 419-424 ◽  
Author(s):  
CYNTHIA DOUGHTY ◽  
JANET E. BOOTH ◽  
P. G. McDONALD ◽  
R. F. PARROTT
Keyword(s):  
Rat Brain ◽  
Sexual Differentiation ◽  
Neonatal Rat ◽  
Female Rats ◽  
Sexual Receptivity ◽  
Female Rat ◽  
Neonatal Rats ◽  
Oestradiol Benzoate ◽  
Ovarian Cyclicity ◽  
Neonatal Rat Brain

SUMMARY Groups of neonatal female rats were treated for the first 5 days of life with oestradiol-17β, oestradiol benzoate or a synthetic oestrogen, 11β-methoxy-17-ethynyl-1,3,5(10)-oestratriene-3,17β-diol (RU 2858), in daily doses ranging from 0·5 to 1000 ng. Oestradiol-17β had no effect on adult ovarian cyclicity or sexual receptivity after ovariectomy and oestrogen + progesterone treatment. Ovarian cyclicity was prevented by 100 ng or more oestradiol benzoate/day, and by all doses of RU 2858. Only rats receiving 50 ng oestradiol benzoate/ day or 0·5 ng RU 2858/day showed normal receptivity. The defeminizing action of RU 2858 was at least 100 times greater than that of oestradiol benzoate; it is suggested that this greater potency is due to the low affinity of RU 2858 for the oestradiol-binding protein in the plasma of neonatal rats. These results indicate that defeminization of the neonatal rat brain can be induced by physiological amounts of oestrogen, and are discussed with reference to the action of testosterone.

Sex Differences in Glutamic Acid Decarboxylase mRNA in Neonatal Rat Brain: Implications for Sexual Differentiation

1996 ◽  
Vol 30 (4) ◽  
pp. 538-552 ◽  
Author(s):  
Aline M. Davis ◽  
David R. Grattan ◽  
Michael Selmanoff ◽  
Margaret M. Mccarthy
Keyword(s):  
Sex Differences ◽  
Glutamic Acid ◽  
Rat Brain ◽  
Glutamic Acid Decarboxylase ◽  
Sexual Differentiation ◽  
Neonatal Rat ◽  
Acid Decarboxylase ◽  
Neonatal Rat Brain

Aromatization: Important for sexual differentiation of the neonatal rat brain

1977 ◽  
Vol 9 (3) ◽  
pp. 249-263 ◽  
Author(s):  
Bruce S McEwen ◽  
Ivan Lieberburg ◽  
Claude Chaptal ◽  
Lewis C Krey
Keyword(s):  
Rat Brain ◽  
Sexual Differentiation ◽  
Neonatal Rat ◽  
Neonatal Rat Brain

Oestrogen receptors and effects of oestradiol administration on mRNA synthesis in the limbic system of the neonatal female rat

1989 ◽  
Vol 120 (1) ◽  
pp. 83-88 ◽  
Author(s):  
B. D. Greenstein ◽  
I. M. Adcock
Keyword(s):  
Sexual Dimorphism ◽  
Rat Brain ◽  
Limbic System ◽  
Oestrogen Receptor ◽  
Neonatal Rat ◽  
Oestrogen Receptors ◽  
Mrna Synthesis ◽  
Isoelectric Focussing ◽  
Oestradiol Benzoate ◽  
Neonatal Rat Brain

ABSTRACT There is sexual dimorphism of specific species of mRNA in the neonatal rat brain and this sexual dimorphism may be imprinted by steroids of testicular origin during the perinatal period. According to current theories, only aromatizable androgens may cause sexual differentiation of sexual behaviour and function in the adult. The effects of oestradiol benzoate on mRNA synthesis in the neonatal female limbic system were therefore studied. In addition, cytosolic and nuclear oestrogen receptors were measured after administration of testosterone propionate, oestradiol benzoate or dihydrotestosterone (DHT). An attempt was made to distinguish between the brain oestrogen receptor and the plasma oestrogen-binding protein, alphafoetoprotein (AFP) by isoelectric focussing. After injection of 50 μg oestradiol benzoate s.c. to neonatal female rats, the expression of mRNA coding for sexually dimorphic proteins appeared to be changed to a male-type pattern. The overall density of labelling was noticeably greater and specific changes in labelled proteins were observed. These effects were observed within 3 h of injection. Both testosterone and oestradiol caused a marked depletion of cytosolic oestrogen receptors in the limbic system whereas DHT was ineffective in this respect. Nuclear receptors were present in equal abundance in male- and female-derived nuclei and only oestradiol was able to cause a significant (P < 0·025) increase in nuclear oestrogen receptors. The receptor and AFP could be distinguished by isoelectric focussing, since the pI of the receptor was 7·05, while that of AFP was 4·5. These results are consistent with the possibility that oestradiol alters transcription in the neonatal rat brain and may do this through the oestrogen receptor. Nevertheless, it is also possible that oestradiol could alter post-transcriptional events such as the stability of mRNA or the binding of tRNA to the polysomal complex. Journal of Endocrinology (1989) 120, 83–88

In vivo diffusion tensor imaging of the neonatal rat brain development

2013 ◽  
Vol 44 (S 01) ◽  
Author(s):  
M Breu ◽  
D Reisinger ◽  
D Wu ◽  
Y Zhang ◽  
A Fatemi ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Brain Development ◽  
Rat Brain ◽  
Diffusion Tensor ◽  
Neonatal Rat ◽  
Neonatal Rat Brain

Effects of maternal essential fatty-acid deficiency on neonatal rat brain

1968 ◽  
Vol 1 (4) ◽  
pp. 225-229 ◽  
Author(s):  
Alan B. Steinberg ◽  
Gregory B. Clarke ◽  
Peter W. Ramwell
Keyword(s):  
Fatty Acid ◽  
Rat Brain ◽  
Essential Fatty Acid ◽  
Essential Fatty Acid Deficiency ◽  
Neonatal Rat ◽  
Acid Deficiency ◽  
Fatty Acid Deficiency ◽  
Neonatal Rat Brain

EFFECTS OF OESTRADIOL AND PROGESTERONE ON THE INDUCTION AND DURATION OF SEXUAL RECEPTIVITY IN CYCLIC FEMALE RATS

1977 ◽  
Vol 74 (3) ◽  
pp. 477-485 ◽  
Author(s):  
P. SÖDERSTEN ◽  
S. HANSEN
Keyword(s):  
Behavioural Response ◽  
Female Rats ◽  
Sexual Receptivity ◽  
Repeated Treatment ◽  
Progesterone Treatment ◽  
Oestradiol Benzoate

SUMMARY Intact 4-day cyclic rats showed sexual receptivity 24 h after an injection of oestradiol benzoate (OB) on any day of the cycle except on the second day after the display of spontaneous oestrus. Ovariectomy at the time of OB treatment abolished the behavioural response, but receptivity was restored by progesterone. Progesterone treatment early on the day of behavioural oestrus advanced the display of receptivity but did not affect the time at which oestrus ended. Repeated treatment of sexually receptive rats with progesterone did not affect the duration of oestrus. These results show that sexual receptivity in the intact rat cannot occur in the absence of oestradiol and progesterone. The results further suggest that progesterone may not be associated with the mechanisms terminating behavioural oestrus in rats. Treatment with OB on the day of oestrus can prolong the duration of receptivity but only at a higher dosage than that needed for induction of receptivity.

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