Importance of central catecholamines in the mediation of lordosis behaviour in ovariectomized rats treated with estrogen and inhibitors of monoamine synthesis

1972 ◽  
Vol 33 (4) ◽  
pp. 247-255 ◽  
Author(s):  
S. Ahlenius ◽  
J. Engel ◽  
H. Eriksson ◽  
K. Modigh ◽  
P. S�dersten
Keyword(s):  
Ovariectomized Rats ◽  
Monoamine Synthesis ◽  
Lordosis Behaviour

Metabolism of dihydrotestosterone to 3α-androstanediol in brain and plasma: effect on behavioural activity in female rats

1992 ◽  
Vol 134 (2) ◽  
pp. 183-195 ◽  
Author(s):  
M. S. Erskine ◽  
M. Hippensteil ◽  
E. Kornberg
Keyword(s):  
Steroid Injection ◽  
Brain Area ◽  
Plasma Concentrations ◽  
Brain Regions ◽  
Significant Inhibition ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Behavioural Activity ◽  
Lordosis Behaviour ◽  
Injection Experiment

ABSTRACT Six experiments were carried out to determine whether dihydrotestosterone (5α-androstan-17β-ol-3-one; DHT) acts to inhibit oestradiol (OE2)-induced lordosis behaviour after its metabolic conversion to 5α-androstane-3α,17β-diol (3α-androstanediol, 3α-Adiol). In experiments 1 and 2, ovariectomized rats were treated with several doses of DHT or 3α-Adiol, injected with OE2 and progesterone, and tested for lordosis responsiveness. Significant inhibition of lordosis occurred after a dose of 3α-Adiol which was approximately threefold less than the effective DHT dose. In experiments 3 and 4, plasma concentrations of DHT and 3α-Adiol were measured after the injection of these steroids to ovariectomized rats at doses shown to be both sufficient or insufficient to inhibit lordosis. Behaviourally effective dosages of DHT and 3α-Adiol produced circulating concentrations of 3α-Adiol greater than those produced by behaviourally ineffective doses of DHT or 3α-Adiol. At 30 min after injection of DHT (experiment 3), 78·8% of plasma androgens were in the form of 3α-Adiol, while after injection of 3α-Adiol, only 7·4% were DHT. When plasma DHT and 3α-Adiol were measured at 3, 6, 9 and 12 h after steroid injection (experiment 4), plasma levels of 3α-Adiol produced by the behaviourally subthreshold dose of DHT were significantly lower than levels produced by behaviourally sufficient dosages of DHT or 3α-Adiol. In experiments 5 and 6, concentrations of DHT and 3α-Adiol were measured in five brain regions 1 and 6 h after injection of behaviourally sufficient doses of these steroids to ovariectomized females. At 1 h after injection, similar levels of DHT and 3α-Adiol were measured in DHT- and 3α-Adiol-injected females, and DHT concentrations in the preoptic area were significantly higher in both groups than in any other brain area. At 6 h, animals injected with DHT had significantly higher levels of DHT in all brain areas combined than did 3α-Adiol-or vehicle-injected animals. Brain concentrations of 3α-Adiol were not different between groups injected with DHT, 3α-Adiol or vehicle at this time. In brain, 34·6% of DHT had been converted to 3α-Adiol after 1 h and 53·0% of 3α-Adiol had been converted to DHT. These results suggest that the inhibitory action of DHT on lordosis may be a consequence of its conversion to 3α-Adiol, and that this conversion may account for the higher behavioural potency of the latter steroid. Journal of Endocrinology (1992) 134, 183–195

A SEXUALLY DIMORPHIC RHYTHM IN OESTRADIOL-ACTIVATED LORDOSIS BEHAVIOUR IN THE RAT

1979 ◽  
Vol 83 (2) ◽  
pp. 267-274 ◽  
Author(s):  
S. HANSEN ◽  
P. SÖDERSTEN ◽  
P. ENEROTH ◽  
B. SREBRO ◽  
K. HOLE
Keyword(s):  
Daily Rhythm ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Sexually Dimorphic ◽  
Female Rat ◽  
Suprachiasmatic Nuclei ◽  
Light Darkness ◽  
Lordosis Behaviour ◽  
Neonatal Castration

Ovariectomized rats exposed to constant plasma levels of oestradiol showed a daily rhythm in lordosis behaviour, with high levels of lordosis occurring during the dark portion of the daily light: darkness cycle and low levels during the light period. Similarly treated male rats failed to show a rhythm in lordosis behaviour. However, neonatal castration permitted the expression of the lordosis rhythm in male rats; conversely, an injection of 1·25 mg testosterone propionate on day 4 of life abolished the rhythm in female rats. Pinealectomy, adrenalectomy or depletion of brain 5-hydroxytryptamine levels did not affect the periodicity in lordosis behaviour but lesions in the suprachiasmatic nuclei of the hypothalamus disrupted the rhythm. It is suggested that the daily rhythm in lordosis behaviour participates in the control of the termination of heat in the female rat and that the perinatal hormone milieu may exert permanent effects on periodic functions.

Role of the uterine cervix in inhibition of sexual behaviour in lactating rats

1985 ◽  
Vol 106 (2) ◽  
pp. 183-188 ◽  
Author(s):  
G. Forsberg ◽  
P. Södersten ◽  
P. Eneroth
Keyword(s):  
Sexual Behaviour ◽  
Uterine Cervix ◽  
Subsequent Treatment ◽  
Ovariectomized Rats ◽  
Serum Prolactin ◽  
Serum Progesterone ◽  
Concurrent Treatment ◽  
Lordosis Behaviour ◽  
Cervical Stimulation

ABSTRACT Treatment of ovariectomized rats with progesterone-filled constant-release implants, which increased serum progesterone concentrations to 99·4 ±5·0 nmol/l, facilitated the induction of lordosis behaviour by subsequent treatment with oestradiol benzoate (OB, 10 μg). Concurrent treatment with the dopamine receptor antagonist domperidone (two daily injections of 2·5 mg/rat), which increased serum prolactin concentrations, did not inhibit the behavioural response of ovariectomized progesterone-treated rats to OB. If the treatment was combined with stimulation of the uterine cervix it inhibited lordosis to a level which was comparable with that of progesterone–domperidone-treated rats, which had been ovariectomized and from which the pups had been removed on the day of parturition. The cervical stimulation did not increase the amount of prolactin secreted by the pituitary gland in response to an injection of domperidone. The behavioural effect of cervical stimulation was blocked by injecting an anaesthetic paste (0·1 ml lidocain–prilocain) intravaginally against the cervix. The effect of cervical stimulation, or of parturition, lasted only for a few days and sexual behaviour was inhibited during a prolonged period of lactation. Sucking by the pups on the nipples of the mother may be required for preventing sexual behaviour during the entire period of lactation. J. Endocr. (1985) 106, 183–188

Activation of sexual behaviour in castrated rats: the role of oestradiol

1986 ◽  
Vol 111 (3) ◽  
pp. 455-462 ◽  
Author(s):  
P. Södersten ◽  
P. Eneroth ◽  
T. Hansson ◽  
A. Mode ◽  
D. Johansson ◽  
...  
Keyword(s):  
Sexual Behaviour ◽  
Reductase Inhibitor ◽  
Low Dose ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
High Dose ◽  
Hypothalamic Tissue ◽  
Lordosis Behaviour

ABSTRACT Sexual behaviour was induced in castrated male rats with oestradiol-17β- or testosterone-filled constant-release implants. Testosterone-induced sexual behaviour was unaffected by treatment with the 5α-reductase inhibitor 17β-N,N-diethylcarbamoyl-4-aza-5α-androstan-3-one (4-MA; 16·7 mg/day) but treatment with the aromatization inhibitor 1,4,6-androstatriene-3,17-dione (ATD; 10 mg/day) prevented testosterone from inducing the behaviour. Sexual behaviour could be activated in castrated rats treated with testosterone plus ATD by treatment with 4-MA or with implants filled with a low dose of oestradiol. Lordosis behaviour induced in ovariectomized rats with testosterone-filled implants and progesterone was blocked by ATD treatment and could not be activated with 4-MA but oestradiol implants restored the display of lordosis in the testosterone plus ATD-treated females. 4-MA inhibited the in-vitro formation of [14C]5α-dihydrotestosterone from [14C]testosterone by combined preoptic and hypothalamic tissue at all doses tested and a high dose of oestradiol exerted a similar effect. The results suggest that androgen aromatization is required for testosterone-activated female sexual behaviour but not for testosterone-activated male sexual behaviour. It is suggested that oestradiol normally acts to control the sexual behaviour of male rats by modifying neural androgen metabolism. J. Endocr. (1986) 111, 455–462

Estrogenic effects of pomegranate extracts in ovariectomized rats

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
W Promprom ◽  
W Lijuan ◽  
P Munglue ◽  
P Kupittayanant ◽  
K Indrapichate ◽  
...  
Keyword(s):  
Ovariectomized Rats ◽  
Estrogenic Effects

Anti-osteoporotic effect of Eucommia ulmoides cortex in ovariectomized rats

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
B Kim ◽  
DW Lim ◽  
J Song ◽  
H Kim
Keyword(s):  
Ovariectomized Rats ◽  
Eucommia Ulmoides

IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS AND HYPOPHYSIS OF THE RAT

1970 ◽  
Vol 64 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Junzo Kato
Keyword(s):  
Incubation Medium ◽  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
Ovariectomized Rats ◽  
Free Medium ◽  
Cortex Cerebri ◽  
Anterior Hypophysis ◽  
In Vitro Uptake

ABSTRACT The anterior, middle, and posterior hypothalamus, the cortex cerebri, the anterior hypophysis as well as the diaphragm of adult ovariectomized rats were incubated in vitro with tritiated 17β-oestradiol. The uptake of tritiated oestradiol was differentially distributed intracerebrally with higher accumulation in the anterior hypothalamus and the hypophysis. Lowering the temperature of the incubation medium caused a reduction in the uptake of radioactivity by the anterior hypothalamus as compared to that found in other brain tissues. Tritiated oestradiol taken up in vitro by the anterior hypothalamus and the hypophysis tended to be retained after further incubation in a steroid-free medium. The addition of non-radioactive 17β-oestradiol to the medium inhibited the uptake of tritiated oestradiol by these tissues. Moreover, pretreatment with non-radioactive 17β-oestradiol in vivo prevented the preferential accumulation of tritiated oestradiol in vitro in the anterior hypothalamus and the hypophysis. These results indicate that oestradiol is preferentially taken up in vitro by the anterior hypothalamus and the hypophysis of the rat.

A new model for the induction of proestrus-like LH surges by estradiol in long-term ovariectomized rats

1985 ◽  
Vol 110 (1_Suppla) ◽  
pp. S11
Author(s):  
C. HIEMKE ◽  
A. SCHMID ◽  
R. GHRAF
Keyword(s):  
Ovariectomized Rats ◽  
New Model
Sign in / Sign up

Export Citation Format

Share Document