OESTROGEN RESPONSES OF RATS NEONATALLY STERILIZED WITH STEROIDS

1969 ◽  
Vol 45 (3) ◽  
pp. 415-420 ◽  
Author(s):  
T. R. WRENN ◽  
JOAN R. WOOD ◽  
J. BITMAN
Keyword(s):  
Testosterone Propionate ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Uterine Weight ◽  
Oestradiol Benzoate

SUMMARY At 75 days of age, female rats neonatally sterilized with oestradiol benzoate or testosterone propionate were compared with normal and ovariectomized rats with regard to their 6-hr. response to 0·2 μg. oestradiol 17β. The greatest increases in uterine weight, glucose and glycogen concentrations and per cent uterine water occurred in the ovariectomized animals. A marked oestrogen response also occurred in the animals neonatally sterilized with oestradiol benzoate. The response of the normal rats was slight, and the testosterone propionate-treated rats were the least affected. Adrenal, pituitary, and ovarian weights were found to be affected by the neonatal hormone treatments. Vaginal patency was completely inhibited in the rats injected with testosterone propionate. It is concluded that rats neonatally sterilized with steroids are much less suitable than ovariectomized animals for oestrogen assays.

scholarly journals Different mechanisms of regulation of nuclear reduced nicotinamide–adenine dinucleotide phosphate-dependent 3-oxo steroid 5α-reductase activity in rat liver, kidney and prostate

1974 ◽  
Vol 142 (2) ◽  
pp. 273-277 ◽  
Author(s):  
Jan-Åke Gustafsson ◽  
Åke Pousette
Keyword(s):  
Testosterone Propionate ◽  
Reductase Activity ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Female Rats ◽  
Male Rats ◽  
Regulatory Mechanisms ◽  
Oestradiol Benzoate ◽  
Liver And Kidney ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Hydroxy Steroid

The regulatory mechanisms involved in the control of the nuclear NADPH-dependent 3-ketosteroid 5α-reductase (5α-reductase) activity were studied in liver, kidney and prostate. The substrate used was [1,2-3H]androst-4-ene-3,17-dione (androstenedione) (for liver and kidney) or [4-14C]androstenedione (for prostate). The hepatic nuclear 5α-reductase activity was greater in female than in male rats, was greater in adult than in prepubertal female rats, increased after castration of male rats, but was not affected by treatment with testosterone propionate or oestradiol benzoate. These regulatory characteristics are in part different from those previously described for the hepatic microsomal 5α-reductase. The renal nuclear metabolism of androstenedione, i.e. 5α reduction and 17β-hydroxy steroid reduction, was relatively unaffected by sex, age, castration and treatment with testosterone propionate. However, treatment of castrated male rats with oestradiol benzoate led to a significant increase in the 5α-reductase activity and a significant decrease in the 17β-hydroxy steroid reductase activity. Finally, the nuclear 5α-reductase activity in prostate was androgen-dependent, decreasing after castration and increasing after treatment with testosterone propionate. In conclusion, the nuclear 5α-reductase activities in liver, kidney and prostate seem to be under the control of distinctly different regulatory mechanisms. The hypothesis is presented that whereas the prostatic nuclear 5α-reductase participates in the formation of a physiologically active androgen, 5α-dihydrotestosterone, this may not be the true function of the nuclear 5α-reductase in liver and kidney. These enzymes might rather serve to protect the androgen target sites in the chromatin from active androgens (e.g. testosterone) by transforming them into less active androgens (e.g. 5α-androstane-3,17-dione and/or 5α-dihydrotestosterone).

scholarly journals Comparative effects of testosterone propionate, oestradiol benzoate, ICI 182,780, tamoxifen and raloxifene on hypothalamic differentiation in the female rat

2002 ◽  
Vol 172 (3) ◽  
pp. 441-448 ◽  
Author(s):  
L Pinilla ◽  
ML Barreiro ◽  
LC Gonzalez ◽  
M Tena-Sempere ◽  
E Aguilar
Keyword(s):  
Positive Feedback ◽  
Testosterone Propionate ◽  
Reproductive Function ◽  
Female Rats ◽  
Normal Brain ◽  
Female Rat ◽  
Vaginal Opening ◽  
Ici 182,780 ◽  
Oestradiol Benzoate ◽  
Normal Differentiation

Hypothalamic differentiation in the female rat during the neonatal period is critically dependent on the steroid milieu, as permanent changes in reproductive function are observed after administration of oestradiol and testosterone during such a critical stage. Selective oestrogen modulators (SERMs) constitute a family of drugs that, depending on the tissue, are able to exert oestrogenic or antioestrogenic actions. The present experiments were conducted to analyse whether the SERMs, tamoxifen and raloxifene, can cause oestrogenic actions during the hypothalamic differentiation period. Postnatal female rats were injected between days 1 and 5 with 100 microg/day tamoxifen, raloxifene or ICI 182,780 (a pure antioestrogen). Other groups of animals were injected on day 1 of age with 100 microg oestradiol benzoate (OeB) or 1.25 mg testosterone propionate (TP) alone or in combination with raloxifene (500 microg/day between days 1 and 5). In all experimental groups, the age, body weight and concentrations of serum gonadotrophins at vaginal opening were recorded, whereas vaginal cyclicity and the negative and positive feedback between oestradiol and LH were monitored in adulthood. The results obtained confirmed the ability of high doses of OeB or TP to alter the normal differentiation of the brain permanently. They also reinforced the hypothesis that oestrogens are also necessary for normal brain differentiation in female rats because administration of a pure antioestrogen, such as ICI 182,780 permanently altered the function of the reproductive axis. In addition, our data provided evidence for different actions of the two SERMs under analysis (raloxifene and tamoxifen) upon peripheral targets, as raloxifene advanced vaginal opening whereas tamoxifen did not. In contrast, their actions on brain differentiation appeared similar and analogous to those obtained after neonatal administration of oestradiol, as evidenced by vaginal acyclicity, ovarian atrophy, sterility and abolition of negative and positive feedback between oestradiol and LH, thus suggesting an oestrogenic action of these SERMs on hypothalamic differentiation. Moreover, the oestrogenic activity of raloxifene was supported by its inability to block the effects of OeB and TP administered neonatally. In conclusion, the present results indicated that the SERMs, tamoxifen and raloxifene, exert an oestrogen-like effect upon hypothalamic differentiation of the neonatal female rat.

EFFECTS OF TESTOSTERONE PROPIONATE TREATMENT OF NEONATALLY OVARIECTOMIZED RATS ON GROWTH AND SUBSEQUENT RESPONSIVENESS TO OESTROGEN

1976 ◽  
Vol 82 (3) ◽  
pp. 652-660 ◽  
Author(s):  
M. F. Tarttelin ◽  
J. E. Shryne ◽  
R. A. Gorski
Keyword(s):  
Body Weight ◽  
Testosterone Propionate ◽  
Neonatal Period ◽  
Specific Effect ◽  
Ovariectomized Rats ◽  
Inhibitory Effects ◽  
Androgen Treatment ◽  
Ovx Rats ◽  
Significant Difference ◽  
Oestradiol Benzoate

ABSTRACT There was no significant difference in body weight between neonatally ovariectomized (OvX) rats whether given oil treatment or 90 μg testosterone propionate (TP) on day 3, when examined up to 23 weeks of age. When these two animals were injected with oestradiol benzoate (3 μg/day for 2 weeks), the neonatally OvX TP treated rats showed a significantly smaller depression in body weight than did the control neonatally OxX rats. Measurement of food intake also showed that TP treated rats responded significantly less to the depressant effects of oestrogen than did the controls. These data are consistent with the hypothesis that the ovary does restrain body weight in TP rats but that androgen treatment in the neonatal period may not have a specific effect on growth but may alter the sensitivity of growth regulating processes to the inhibitory effects of oestrogen.

SERUM CORTICOSTERONE IN RATS WITH DELAYED ANOVULATION

1976 ◽  
Vol 71 (1) ◽  
pp. 31-36 ◽  
Author(s):  
JUDITH A. RAMALEY
Keyword(s):  
Low Dose ◽  
Testosterone Propionate ◽  
Ovariectomized Rats ◽  
Tube Length ◽  
Blood Levels ◽  
Early Exposure ◽  
Vaginal Opening ◽  
Adrenal System ◽  
Oestradiol Benzoate ◽  
Intact Rats

SUMMARY The purpose of this study was to investigate adrenal function in rats during the development of persistent oestrus to determine whether a change in blood levels of corticosterone would precede or coincide with the onset of infertility. The syndrome of delayed persistent oestrus and anovulation was induced by administration of a low dose (10 μg) of testosterone propionate (TP) at 5 days of age. Control animals were handled without injection or received the vehicle (sesame oil) only. Half of each group was ovariectomized at weaning and received Silastic implants of either oestradiol benzoate (OB) or cholesterol, 3 mm tube length/100 g body weight. Intact rats given the low TP dose showed precocious vaginal opening (27·3 ± 2·1 days v. 37·6 ± 2·4 (s.e.m.) days in unhandled controls) and ovulated within 2 days. Persistent vaginal cornification developed in 22 out of 26 rats by 75 days of age. The TP-treated rats had higher corticosterone values than the controls and did not show a further increase after OB implantation. Cholesterol implantation depressed corticosterone levels in the TP-treated rats. The effects of the low TP dose were not dependent upon gonadal function since they persisted in ovariectomized rats. The results suggest that early exposure to androgen can modify the sensitivity of the adrenal system to oestrogen, and can also lead to persistently high values of corticosterone which are not depressed by ovariectomy. These changes precede the onset of persistent oestrus.

scholarly journals Preventive Effects of Collagen Peptide from Deer Sinew on Bone Loss in Ovariectomized Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
He Zhang ◽  
Ying Dong ◽  
Bin Qi ◽  
Li Liu ◽  
Guangxin Zhou ◽  
...  
Keyword(s):  
Body Weight ◽  
Bone Loss ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Uterine Weight ◽  
Mineral Density ◽  
Active Constituent ◽  
Collagen Peptide ◽  
Calcium Phosphorus ◽  
Serum Biochemical

Deer sinew (DS) has been used traditionally for various illnesses, and the major active constituent is collagen. In this study, we assessed the effects of collagen peptide from DS on bone loss in the ovariectomized rats. Wister female rats were randomly divided into six groups as follows: sham-operated (SHAM), ovariectomized control (OVX), OVX given 1.0 mg/kg/week nylestriol (OVX + N), OVX given 0.4 g/kg/day collagen peptide (OVX + H), OVX given 0.2 g/kg/day collagen peptide (OXV + M), and OVX given 0.1 g/kg/day collagen peptide (OXV + L), respectively. After 13 weeks of treatment, the rats were euthanized, and the effects of collagen peptide on body weight, uterine weight, bone mineral density (BMD), serum biochemical indicators, bone histomorphometry, and bone mechanics were observed. The data showed that BMD and concentration of serum hydroxyproline were significantly increased and the levels of serum calcium, phosphorus, and alkaline phosphatase were decreased. Besides, histomorphometric parameters and mechanical indicators were improved. However, collagen peptide of DS has no effect on estradiol level, body weight, and uterine weight. Therefore, these results suggest that the collagen peptide supplementation may also prevent and treat bone loss.

THE EFFECT OF HEPATECTOMY AND SEX HORMONES ON THE PSEUDOCHOLINESTERASE ACTIVITY IN LIVER AND SERUM OF THE RAT

1970 ◽  
Vol 65 (1) ◽  
pp. 184-192 ◽  
Author(s):  
R. S. Leeuwin ◽  
E. Th. Groenewoud
Keyword(s):  
Sex Hormones ◽  
Testosterone Propionate ◽  
Marked Decrease ◽  
Normal Values ◽  
Female Rats ◽  
Slow Increase ◽  
Male And Female Rats ◽  
Oestradiol Benzoate ◽  
Synthetic Capacity ◽  
Low Activity

ABSTRACT A study was made of the combined effects of hepatectomy, castration and treatment with sex hormones on the pseudocholinesterase activity in liver and serum of male and female rats. Hepatectomy in normal rats results in a sharp decline of the pseudocholinesterase activity, subsequently followed in females by a rapid increase to normal values and in males by a very slow increase. Hepatectomy in castrated rats also causes a marked decrease of the pseudocholinesterase activity, but the pseudocholinesterase activity remains at a relatively low level, in both castrated females and castrated males. Daily treatment of castrated-hepatectomized females with oestradiol-benzoate, either immediately or nine days after hepatectomy induces a gradual restoration of the enzyme activity to and above the normal castrate level. When castrated-hepatectomized males are treated daily with testosterone-propionate the extremely low activity may even be depressed further. These experiments once again stress the important role played by the liver and by sex hormones in the synthesis of the enzyme pseudocholinesterase. There was no evidence from our experiments that the steroid hormones affect the speed of regeneration of the liver as a whole. From this it must be decided that they only affect the restoration of the synthetic capacity for pseudocholinesterase. In all experiments the changes in liver pseudocholinesterase activity were reflected in the serum activity.

Dissociation between the ovarian factors controlling sexual receptivity and preovulatory secretion of LH in cyclic female rats

1987 ◽  
Vol 112 (1) ◽  
pp. 133-138 ◽  
Author(s):  
P. Södersten ◽  
P. Eneroth
Keyword(s):  
Sexual Behaviour ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Sexual Receptivity ◽  
Serum Progesterone ◽  
Lh Surge ◽  
Oestradiol Benzoate ◽  
Lh Release ◽  
Lh Secretion ◽  
Intact Rats

ABSTRACT Ovariectomy and treatment with oestradiol benzoate (10 μg OB) on the day before behavioural oestrus eliminated the preovulatory surge of LH and reduced the level of sexual receptivity on the following day. Sexual behaviour, but not the LH surge, was restored by progesterone (0·5 mg) given 18 h later. Injection of OB on the day after behavioural oestrus induced a small release of LH and normal sexual behaviour on the following day. Ovariectomy on the day after behavioural oestrus reduced the stimulatory effect of OB on sexual behaviour and eliminated its weakly stimulatory effect on LH release. Sexual behaviour, but not the small LH surge, was restored in these animals by progesterone (0·5 mg) given 18 h later. Treatment of rats ovariectomized 2 days before the day of the LH surge with implants containing oestradiol or injections of oestradiol (1 μg) induced LH surges but the amplitudes of these LH surges were much smaller than those of the normal LH surge. Treatment of intact rats with OB increased serum progesterone levels 24 h later, an effect which was eliminated by ovariectomy. Injections of LH (20 μg) into intact rats on the day after behavioural oestrus also increased serum progesterone concentrations but failed to stimulate sexual behaviour. It is suggested that OB treatment of intact rats on the day after behavioural oestrus stimulates sexual behaviour by inducing a surge of LH secretion which activates ovarian secretion of progesterone. Thus, oestrogen and progesterone but not the LH surge are essential for sexual behaviour. Whereas oestradiol and progesterone restore normal sexual behaviour in ovariectomized rats, additional ovarian factors may be required for induction of normal LH surges. J. Endocr. (1987) 112, 133–138

scholarly journals Estrogenic Activity of Ethanolic Extract of Papaya Peels (Carica Papaya L.) on Uterine Weight and Mammae Gland Proliferation on Ovariectomy Rats

2018 ◽  
Vol 9 (2) ◽  
pp. 86 ◽  
Author(s):  
Dhania Novitasari ◽  
Devyanto Hadi Triutomo ◽  
Fitriana Hayyu Arifah ◽  
Anselma Ivanawati ◽  
Zahrotul Ulum ◽  
...  
Keyword(s):  
Estrogenic Activity ◽  
Ethanolic Extract ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Uterine Weight ◽  
Sprague Dawley ◽  
In Vivo Test ◽  
Female Reproductive Health ◽  
Agnor Staining

Papaya bark is one of Indonesia's natural wealth that contains flavonoid compounds such as myricetin and kaempferol that included in the phytoestrogen compounds. The aim of this study is to examine the estrogenic effects of ethanolic extract of papaya peels (EEPP), on the development of mammae gland and the increasing of uterine weight. The in vivo test was performed with ovariectomy in Sprague Dawley female rats that caused the rats to be in an estrogen deficiency state. After 30 days of treatment, animals are sacrificed to take the uterus and mammae glands. Measurement of uterine weight and mammae gland are observed by hematoxylin-eosin staining method to know the lobulus development and AgNOR staining to determine the proliferation level of mammae gland epithelial cells. The test results showed that EEPP concentration of 500 and 1000 mg/kgBW were able to increase uterine weight and proliferation of mammae gland. From the results of this study, papaya bark has the potential to be one of the phytoestrogens compound to maintain female reproductive health and woman beauty.Keyword: ethanolic extract of papaya peels (EEPP), phytoestrogen, ovariectomized rats, uterine weight, mammae proliferation

PROGESTERONE TREATMENT INCREASES PITUITARY OESTRADIOL RETENTION IN THE OVARIECTOMIZED NORMAL FEMALE RAT BUT NOT IN THE MALE NOR IN THE ANDROGEN- OR OESTROGEN-STERILIZED FEMALE RAT

1977 ◽  
Vol 84 (2) ◽  
pp. 268-280 ◽  
Author(s):  
Robert D. Lisk ◽  
Lawrence A. Reuter
Keyword(s):  
Testosterone Propionate ◽  
Ovariectomized Rats ◽  
Normal Female ◽  
Nuclear Fraction ◽  
Female Rat ◽  
Treatment Conditions ◽  
Oestradiol Benzoate ◽  
Pre Treatment

ABSTRACT Pituitary retention of [3H]oestradiol in ovariectomized rats was measured following in vivo progesterone pre-treatment and found to be significantly increased after 48, 72, 96 and 120 h of pre-treatment. Increased [3H]oestradiol retention was also observed for at least up to 72 h after removal of the progesterone pre-treatment source. This retention was measured as dpm per mg dry tissue weight. [3H]Oestradiol retention was also measured in the nuclear fraction of tissues incubated with [3H]oestradiol in vitro. Following 72 h of in vivo progesterone pre-treatment, the nuclear fraction from the pituitary was found to retain significantly more [3H]oestradiol than corresponding fractions from non-treated animals. In contrast to ovariectomized females, no increase in [3H]oestradiol retention was found in the pituitary of orchidectomized males pre-treated with progesterone for 72 h. [3H]Oestradiol retention by pituitaries of ovariectomized rats injected on the day of birth with 200 μg oestradiol benzoate (OeB) or 500 μg testosterone propionate (TP) was significantly decreased in comparison to control animals. When the rats were pre-treated in vivo with oestradiol for 6 or 72 h and [3H]oestradiol retention was measured 6 or 24 h after this pre-treatment, the OeB and TP treated animals retained significantly less [3H]oestradiol under most treatment conditions. Progesterone pretreatment for 24 or 72 h in vivo followed by measurement of [3H]oestradiol retention immediately or 6 or 24 h later resulted in a significant increase in [3H]oestradiol retention for the control animals. In contrast, the neonatally OeB or TP treated animals differed significantly by not showing increased retention. When [3H]oestradiol retention of the pituitary was measured in vitro following homogenization at 0°C and incubation at 37°C for 1 h, the nuclear fraction from both OeB and TP treated animals was found to retain less hormone per unit DNA; however, this decrease was significant only for the TP animals. Thus, males and androgen- or oestrogensterilized females have an altered and reduced augmentation of pituitary oestradiol retention in response to both oestrogen and progesterone pretreatments.

Naloxone reverses post-ejaculatory inhibition of sexual behaviour in female rats

1987 ◽  
Vol 113 (3) ◽  
pp. 429-434 ◽  
Author(s):  
G. Forsberg ◽  
I. Bednar ◽  
P. Eneroth ◽  
P. Södersten
Keyword(s):  
Sexual Behaviour ◽  
Opioid Peptide ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Sexual Receptivity ◽  
Peptide Receptor ◽  
Oestradiol Benzoate ◽  
Brain And Spinal Cord ◽  
The Brain

ABSTRACT Sexual receptivity was inhibited in ovariectomized rats treated with oestradiol benzoate (OB: two injections of 2 μg) and progesterone (0·5 mg) immediately after ejaculation by the male and restored after the end of the post-ejaculatory refractory period in the male. The post-ejaculatory inhibition of sexual receptivity was reversed by i.p. (5 mg), intracerebroventricular (50 μg) or intrathecal (50 μg) injection of the opioid peptide receptor antagonist naloxone. The concentration of serum β-endorphin-like immunoreactivity in ovariectomized rats treated with OB plus progesterone was unaltered by sexual interactions with males (18·3 ± 6·0 (s.e.m.), 26·4 ± 2·1 and 21·8 ± 6·1 pmol/l before sexual activity, after ejaculation and after the end of the post-ejaculatory interval) but reduced to non-detectable by hypophysectomy. Subcutaneous injection of 10 μg β-endorphin raised serum concentrations of β-endorphin-like immunoreactivity but did not affect the display of sexual behaviour. The behaviour was also unaffected by intracerebroventricular injection of 0·1, 0·2 or 1·0 μg β-endorphin or by injections of 0·25 μg β-endorphin in the periaqueductal central grey of the mesencephalon. The results show that ejaculation by male rats causes a transient inhibition of sexual receptivity in the female which may be dependent upon opioid peptide receptor mechanisms in the brain and spinal cord. It is unlikely that the peptide is β-endorphin. J. Endocr. (1987) 113, 429–434

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