Hypothalamic and Peripheral Relations during the Oestrous Cycle of the Female Rat: the Oestrogen Receptor in the Uterus

1977 ◽  
Vol 5 (4) ◽  
pp. 1069-1071
Author(s):  
SÉAN THROWER ◽  
LOUIS LIM ◽  
JOHN O. WHITE
Keyword(s):  
Oestrogen Receptor ◽  
Oestrous Cycle ◽  
Female Rat

scholarly journals The nuclear oestrogen receptor in the female rat. Effects of oestradiol administration during the oestrous cycle on the uterus and contrasting effects of progesterone on the uterus and hypothalamus

1981 ◽  
Vol 198 (2) ◽  
pp. 385-389 ◽  
Author(s):  
S Thrower ◽  
L Lim
Keyword(s):  
Adult Female ◽  
Oestrogen Receptor ◽  
Oestrous Cycle ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Oestrogen Receptors ◽  
Adult Rat ◽  
Receptor Interactions ◽  
Neural Tissues

Oestradiol administration to immature or ovariectomized rats has been reported to increase the uterine content of long-term nuclear oestrogen receptors. However, in the intact adult female rat, oestradiol administration did not increase the concentration of long-term nuclear oestrogen receptors at all phases of the oestrous cycle. Progesterone administration to rats in late dioestrus did not affect the concentration of uterine nuclear oestrogen receptors 24 h later, although it did prevent the normal cyclic increase at pro-oestrus in the concentration of hypothalamic nuclear oestrogen receptors. Our results therefore show that in the intact adult rat, factors other than the concentration of progesterone or oestradiol determine the nuclear concentration of oestrogen receptors in the uterus. They also demonstrate differences between neural and non-neural tissues in the regulation of oestrogen-receptor interactions.

scholarly journals Effect of neonatal chronic stress on expression of Hsp70 and oestrogen receptor alpha in the rat oviduct during development and the oestrous cycle

Reproduction ◽  
2003 ◽  
pp. 801-808 ◽  
Author(s):  
ML Mariani ◽  
DR Ciocca ◽  
AS Gonzalez Jatuff ◽  
M Souto
Keyword(s):  
Chronic Stress ◽  
Oestrogen Receptor ◽  
Depressive Disorders ◽  
Adult Life ◽  
Oestrous Cycle ◽  
Stress Model ◽  
Neonatal Development ◽  
Adult Rats ◽  
Receptor Alpha ◽  
Oestrogen Receptor Alpha

A chronic unpredictable stress model used to produce depressive disorders in adult rats was applied to neonatal rats to investigate whether this type of stress can induce changes in the expression of Hsp70 and oestrogen receptor alpha in the oviduct, as detected by immunohistochemistry. Rats stressed during neonatal development showed changes in the expression pattern of Hsp70. In neonatal control rats, Hsp70-positive cells observed in the isthmus did not show any changes. Moreover, rats exposed to this stress model that reached adulthood had higher expression of Hsp70 in the isthmus (P<0.01) but not in the ampulla during oestrus than did the control rats. In contrast, during dioestrus, no significant changes were noted in adult rats that were stressed during neonatal development or in rats that were stressed in adulthood. These findings indicate that the isthmus is very sensitive to stressful stimuli and that repeated pre-weaning stress can change the expression of heat shock proteins in early and adult life. These subtle changes of expression in the oviduct did not affect the fertility of the rats that reached adulthood or that were mated under unstressed conditions. However, the control animals stressed during adulthood showed a disruption of the oestrous cycle: this finding is not observed in rats stressed during neonatal development that show an attenuated oestrous cycle disruption induced by chronic stress in adulthood. Moreover, there was dissociation between the expression of oestrogen receptor alpha and Hsp70. The amount of oestrogen receptor alpha remained constant in the epithelium of the oviduct in the control and in the stressed rats. Expression of oestrogen receptor alpha was noted in the stroma of the oviduct without the concomitant expression of Hsp70. It is possible that in certain cells and tissues Hsp70 is not necessary for oestrogen receptor alpha to be functional or Hsp70 might be present at very low amounts but is sufficient for the receptor to function.

PROGESTERONE IN THE EXPERIMENTAL CONTROL OF THE BEHAVIOURAL SEX CYCLE IN THE FEMALE RAT

1967 ◽  
Vol 38 (3) ◽  
pp. 269-277 ◽  
Author(s):  
I. ZUCKER
Keyword(s):  
Oestrous Cycle ◽  
Female Rat ◽  
Experimental Control ◽  
Biphasic Effect ◽  
Sex Cycle

SUMMARY The effect of injections of progesterone on the length of the behavioural oestrous cycle in rats is described. Administration of the hormone was shown to act differently in rats known to have a 4-day cycle as compared with animals with a 5-day cycle. In the 4-day rat injection of 2 mg. progesterone on the first, second or third day of the cycle retarded the next occurrence of behavioural oestrus by 1–2 days; treatment on day 4 of the cycle was without effect. In 5-day rats treatment with progesterone before day 3 of the cycle delayed the occurrence of behavioural heat in only 35% of animals; treatment on day 3 retarded the occurrence of heat by 1–3 days in all rats. Injections on day 4 advanced heat by 1 day and treatment on day 5 was without effect. Additional experiments compared the responsiveness to progesterone of 'artificial' and natural 5-day rats. The results suggest a biphasic effect of progesterone on induction of behavioural receptivity with time characteristics similar to those observed earlier for ovulation and vaginal cyclicity.

Constitutive expression of heat shock proteins hsp25 and hsp70 in the rat oviduct during neonatal development, the oestrous cycle and early pregnancy

Reproduction ◽  
2000 ◽  
pp. 217-223 ◽  
Author(s):  
ML Mariani ◽  
M Souto ◽  
MA Fanelli ◽  
DR Ciocca
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Early Pregnancy ◽  
Oestrogen Receptor ◽  
Oestrous Cycle ◽  
Receptor Protein ◽  
Neonatal Development ◽  
Receptor Alpha ◽  
Oestrogen Receptor Alpha ◽  
Shock Proteins

Certain heat shock proteins are regulated by steroid hormones and are associated with oestrogen receptor function in reproductive tissues, indicating that these proteins have a role during implantation, decidualization and placentation. In the present study, the expression of hsp25, hsp70 and oestrogen receptor alpha were examined by immunohistochemistry in oviducts from rats during neonatal development, the oestrous cycle and during early pregnancy. Oestrogen receptor alpha was the first protein observed in the neonatal oviduct, and its expression preceded that of hsp70 and hsp25. Although these heat shock proteins have been associated with the oestrogen receptor, this study showed that during early development of the oviduct, the receptor protein was not associated with the concomitant expression of hsp25 and hsp70. However, these heat shock proteins were expressed when oviductal cells became differentiated. In the adult oviduct, hsp70 was more abundant than hsp25, moreover, there were no significant modifications in expression of hsp25 during the oestrous cycle. In contrast, the expression of hsp70 was significantly higher in epithelial cells during dioestrus, when the maximum amount of oestrogen receptor alpha was also observed. Therefore, the present study shows that hsp70, but not hsp25, is an oviductal protein modulated by the oestrous cycle and that it is a protein marker for specific phases of the oestrous cycle. In addition, hsp70 was more responsive to the hormonal changes in the infundibulum and ampullar regions of the oviduct. During early pregnancy, hsp25 expression was downregulated (unlike in the endometrium), whereas hsp70 was relatively abundant in the oviduct. hsp70 was observed in all functional segments of the oviduct during pregnancy, indicating that in the oviduct, this protein is modulated by oestrogens and progesterone and possibly by other pregnancy-related hormones.

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