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

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

INDUCTION OF SEXUAL RECEPTIVITY BY OESTRADIOL BENZOATE IN CYCLIC FEMALE RATS: INFLUENCE OF OVARIAN SECRETIONS BEFORE INJECTION OF OESTRADIOL BENZOATE

1979 ◽  
Vol 80 (3) ◽  
pp. 389-395 ◽  
Author(s):  
P. SÖDERSTEN ◽  
S. HANSEN
Keyword(s):  
Sexual Behaviour ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Sexual Receptivity ◽  
Behavioural Effect ◽  
Progesterone Treatment ◽  
Oestradiol Benzoate

The ability of cyclic female rats to show sexual receptivity 24 h after an injection of 2 μg oestradiol benzoate (OB) was lost 24 h after ovariectomy. Exposure of cyclic rats to anti-oestrogen (nitromophene monocitrate) implants 24 h before ovariectomy and OB treatment prevented the latter from inducing sexual receptivity within 24 h of administration. Treatment of ovariectomized rats with constant release implants filled with an oil solution of 15 μg oestradiol/ml had no behavioural effect in itself, but prepared the rats to show lordosis 24 h after administration of OB. Progesterone treatment (4 mg) induced sexual behaviour in cyclic rats on days other than that of the oestrous cycle when the rats are normally receptive. Evidence is presented that a lower level of oestradiol stimulation than that present during pro-oestrus was needed for the induction of sexual receptivity in ovariectomized rats. It is suggested that the low basal level of oestradiol which was present throughout the oestrous cycle was necessary for the induction of sexual receptivity and that an increase in oestradiol stimulation served to increase the behavioural sensitivity to progesterone.

Naloxone stimulates sexual behaviour in lactating rats

1987 ◽  
Vol 113 (3) ◽  
pp. 423-427 ◽  
Author(s):  
G. Forsberg ◽  
P. Eneroth ◽  
P. Södersten
Keyword(s):  
Receptor Antagonist ◽  
Sexual Behaviour ◽  
Opioid Peptide ◽  
Response To Treatment ◽  
Ovariectomized Rats ◽  
Serum Progesterone ◽  
Dopamine Receptor Antagonist ◽  
Peptide Receptor ◽  
Oestradiol Benzoate ◽  
Cervical Stimulation

ABSTRACT During lactation the display of sexual receptivity in response to treatment with oestradiol benzoate (OB; 2 or 10 μg) and progesterone (0·5 mg) was inhibited, but the behaviour could be activated by i.p. (5 mg) or intracerebroventricular (i.c.v.; 100 μg) but not intrathecal (i.t.; 100 or 500 μg) injections of the opioid peptide receptor antagonist naloxone. The behaviour was also inhibited in ovariectomized rats in which serum progesterone and prolactin levels had been raised by treatment with progesterone implants and the dopamine receptor antagonist domperidone, and the uterine cervix had been stimulated. Intraperitoneal injections of naloxone (1 mg) reactivated the behaviour of cervically stimulated rats. The concentration of β-endorphin-like immunoreactivity in the serum of lactating rats (42·8± 9·2 pmol/l) was not raised above that of ovariectomized rats (35·8 ± 8·4 pmol/l) nor was the concentration of β-endorphin-like immunoreactivity altered in the pituitary gland (22·5 ± 2·5 pmol/l), midbrain central grey (6·3 ± 2·2 pmol/l) or hypothalamus (5·6± 2·6 pmol/l) of lactating rats in comparison with ovariectomized rats (24·8 ± 4·4, 4·0 ± 2·0 and 4·7 ± 1·4 pmol/l respectively). Adrenalectomy facilitated the display of sexual behaviour in lactating rats treated with OB plus progesterone and caused a slight increase in serum β-endorphin-like immunoreactivity (30·5± 2·7 pmol/l) compared with that in non-adrenalectomized lactating rats (26·1 ± 2·1 pmol/l). It is suggested that an opioid peptide, but probably not β-endorphin, inhibits sexual behaviour during lactation and after cervical stimulation. J. Endocr. (1987) 113, 423–427

Measurement of lipogenesis in isolated preputial gland cells of the rat and the effect of oestrogen

1986 ◽  
Vol 109 (1) ◽  
pp. 1-7 ◽  
Author(s):  
A. M. Alves ◽  
A. J. Thody ◽  
C. Fisher ◽  
S. Shuster
Keyword(s):  
Gland Cell ◽  
Lipid Synthesis ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Preputial Gland ◽  
Gland Cells ◽  
Oestradiol Benzoate ◽  
Preputial Glands ◽  
Prior Administration

ABSTRACT Lipogenesis was measured in isolated preputial gland cells of female rats after ovariectomy and after the administration of oestradiol benzoate. Ovariectomy decreased preputial gland cell lipogenesis and also altered the pattern of lipid synthesis, producing a relative decrease in the proportion of polar lipids and an increase in the proportion of 'triglycerides'. Although daily administration of 2 or 10 μg oestradiol benzoate for 7 days produced slight increases in preputial gland cell lipogenesis in ovariectomized rats, the effects were not significant. A single injection of 10 μg oestradiol benzoate, however, produced significant increases in preputial gland cell lipogenesis of ovariectomized rats at both 2 and 24 h and, moreover, at 24 h the pattern of polar lipid and triglyceride labelling was restored to normal. Prior administration of actinomycin D reduced the lipogenic effect of oestradiol benzoate. Oestradiol benzoate had little or no effect on preputial gland cell lipogenesis in male rats. These results confirm that oestrogen is able to stimulate preputial lipogenesis in female rats. Whether this action of oestrogen is related to its pheromone-producing effect on the preputial glands is not yet known. J. Endocr. (1986) 109, 1–7

EFFECT OF OVARIAN STEROIDS ON PREPUTIAL GLAND ODOURS IN THE FEMALE RAT

1978 ◽  
Vol 77 (3) ◽  
pp. 397-403 ◽  
Author(s):  
A. J. THODY ◽  
H. DIJKSTRA
Keyword(s):  
Single Injection ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Whole Body ◽  
Female Rat ◽  
Preputial Gland ◽  
Intact Female ◽  
Oestradiol Benzoate ◽  
Experienced Male

Sexually experienced male rats were used to test for whole body and preputial gland odours of female rats. The male rats clearly preferred whole body odours of intact female rats to those of preputialectomized female rats. The male rats also preferred the odour of preputial gland tissue of intact female rats to that of ovariectomized female rats and were especially attracted to the preputial gland odours of female rats in pro-oestrus and oestrus. The preputial gland odours of ovariectomized rats that had received oestradiol benzoate for 7 days were attractive to male rats, although similar treatment with progesterone was ineffective. However, a single injection of progesterone given 72 h after a single injection of oestradiol benzoate not only made ovariectomized rats receptive, but also made their preputial gland odours attractive to male rats. The results suggest that the preputial gland of the female rat is responsible for odours that serve to attract sexually experienced male rats. Ovarian steroids, as well as controlling receptivity in the female rat, would also appear to control the production of sex attractants in the preputial gland. There was no relationship between the size of the preputial glands and their ability to attract male rats which suggests that preputial gland growth and production of sex attractants are not under the same hormonal control.

A physiological dose of estradiol with progesterone affects striatum biogenic amines

1990 ◽  
Vol 68 (12) ◽  
pp. 1520-1526 ◽  
Author(s):  
Marc Morissette ◽  
Daniel Lévesque ◽  
Alain Bélanger ◽  
Thérèse Di Paolo
Keyword(s):  
Steroid Injection ◽  
Acute Effect ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Rat Striatum ◽  
Plasma Prolactin ◽  
Intact Male ◽  
Hydroxyindoleacetic Acid ◽  
The Brain

The acute effect of estradiol and progesterone on dopamine and serotonin metabolism in rat striatum was studied. One subcutaneous injection of 17β-estradiol (300 ng) and progesterone (150 μg) into intact male rats increased plasma levels of these steroids, while testosterone, corticosterone, and estrone remained unchanged. Dehydroepiandrosterone, androstane-3β, 17β-diol and dihydrotestosterone remained undetectably low. Prolactin decreased and androstane-3α,17β-diol, and 17-OH progesterone increased, but less than estradiol and progesterone. Peak levels of striatal dopamine, dihydroxyphenylacetic acid, and homovanillic acid were observed 15–45 min after steroid injection with a return to control values after 45–60 min, while serotonin and 5-hydroxyindoleacetic acid levels were slightly decreased. An injection of estradiol (70 ng) with progesterone (70μg) to ovariectomized female rats left plasma prolactin levels unchanged, while striatum dopamine and serotonin as well as their metabolite concentrations peaked 15–60 min after steroid injection and returned to control values after 45–75 min. To allow for a better comparison of the action of these steroids, the effect of estradiol or progesterone alone and in combination on the brain of ovariectomized rats was compared in the same experiment. A similar increase in metabolites of dopamine levels was observed after these steroids alone or in combination, while dopamine levels were increased only after progesterone alone or in combination with estradiol. An injection of estradiol or progesterone to ovariectomized rats led to peak steroid concentrations at approximately the same time in the brain and plasma. In addition, plasma and brain steroid levels were significantly correlated. Thus, levels of estradiol and progesterone that occur during the estrous cycle can rapidly increase striatum dopaminergic activity in rats of both sexes, while serotonin activity is increased only in female rats.Key words: estradiol, progesterone, striatum, dopamine, serotonin.

INDUCTION OF SEXUAL RECEPTIVITY IN OVARIECTOMIZED RATS BY PULSE ADMINISTRATION OF OESTRADIOL-17β

1981 ◽  
Vol 89 (1) ◽  
pp. 55-62 ◽  
Author(s):  
P. SÖDERSTEN ◽  
P. ENEROTH ◽  
S. HANSEN
Keyword(s):  
Single Injection ◽  
Serum Levels ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Sexual Receptivity ◽  
Behavioural Responses ◽  
Time Points ◽  
Progesterone Treatment ◽  
Oestradiol Benzoate ◽  
Stimulation Of

Constant-release implants filled with oestradiol-17β induced sexual receptivity in ovariectomized rats in response to progesterone treatment if they were implanted 32 h before behavioural testing. A 20 h period of exposure to oestradiol, by implantation 32 h before testing and removal of the implants 20 h later, was sufficient for induction of the behaviour. The exposure time necessary for behavioural responses could be further reduced to two 4 h periods, between 32 and 28 h and between 16 and 12 h, before testing. Serum levels of oestradiol were raised within 1 h of oestradiol implantation and declined rapidly after implant removal. A single injection of oestradiol benzoate was much more potent than a single injection of oestradiol in inducing sexual receptivity in ovariectomized rats, but this difference in potency was reversed if two appropriately timed injections were given. Oestrone- or oestriol-filled implants were relatively ineffective in inducing sexual receptivity. It is suggested that oestradiol has to be present at crucial time points to prepare an ovariectomized rat to respond behaviourally to progesterone treatment and that oestradiol is the principal oestrogen in the stimulation of sexual behaviour in female rats.

EFFECTS OF DIHYDROTESTOSTERONE AND OESTRADIOL ON SEXUAL DIFFERENTIATION IN MALE RATS

1980 ◽  
Vol 84 (3) ◽  
pp. 397-407 ◽  
Author(s):  
P. VAN DER SCHOOT
Keyword(s):  
Sexual Differentiation ◽  
Testosterone Propionate ◽  
Neonatal Period ◽  
Combined Treatment ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Oestradiol Benzoate ◽  
The Brain ◽  
Copulatory Behaviour

Adult male rats which had been castrated at birth and treated with the non-aromatizable androgen dihydrotestosterone propionate (DHTP) showed incomplete copulatory behaviour. When tested with oestrous female rats during treatment with testosterone propionate (TP) they readily mounted these females and showed frequent penile intromissions but rarely ejaculated. In a long series of observations the proportion of ejaculating rats in tests of 30 min did not exceed 50%. Neonatally castrated rats treated with DHTP during infancy thus seemed to be capable of ejaculation in adulthood during treatment with TP, but the threshold for the occurrence of the ejaculatory reflex seemed to be higher than in normal male rats. By replacing treatment in adulthood with TP by a combined treatment with DHTP and oestradiol benzoate (OB), the frequency of ejaculation was not increased. It was concluded that the incomplete copulatory behaviour was not due to reduced efficiency of aromatization of androgen within the brain of these rats. The addition of OB to DHTP during the neonatal period of treatment enhanced the frequency of ejaculation in adulthood. The combined treatment of 0·1 mg DHTP on days 1, 3 and 5 with 0·01 mg OB on day 1 made adult copulatory behaviour during treatment with TP indistinguishable from that of rats castrated on day 10 or rats castrated at birth and treated with TP during infancy. It was concluded that the masculine organization of systems and structures involved in the display of male copulatory behaviour occurs under the influence of both non-aromatizable androgen and oestrogen, oestrogen being most likely the substance required to 'organize' the central nervous aspects of the regulation of this behaviour. The absence neonatally of nonaromatizable androgen and/or oestrogen results in specific deficiencies in adult copulatory behaviour as compared with the behaviour of normal male rats.

LORDOSIS BEHAVIOUR IN IMMATURE MALE RATS

1978 ◽  
Vol 76 (2) ◽  
pp. 233-240 ◽  
Author(s):  
P. SÖDERSTEN
Keyword(s):  
Normal Development ◽  
Single Injection ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Tb Treatment ◽  
Oestradiol Benzoate ◽  
Lordosis Behaviour ◽  
The Brain

Lordosis behaviour was induced in immature 20-day-old male rats by sequential treatment with oestradiol benzoate (OB) and progesterone, but prepubertal male rats were behaviourally less sensitive to the OB and progesterone treatment than were female rats. Thus, the sex difference in the lordosis response was present early during development. Castration at various times after birth showed that the capacity of immature rats to show lordosis is normally inhibited by an action of testicular secretions exerted during the first 10 days of life. Treatment of day 0 castrated rats with OB, either as a single injection given on the day of birth or as daily injections given on the first 10 days after birth, was much more effective in inhibiting the display of lordosis behaviour at 30 and 37 days of age than was treatment with testosterone benzoate (TB). Treatment with dihydrotestosterone benzoate neonatally had no inhibitory effect. Treatment of intact male rats or day 0 castrated OB-or TB-treated rats with the anti-oestrogen ethamoxytriphetol (MER-25) during the first 10 days of life antagonized the inhibitory effect of the testes and of the OB or TB treatment on the development of the lordosis response. It is suggested that during normal development oestradiol formed in the brain from testosterone in the circulation acts during the first 10 days of life to inhibit the capacity of male rats to show lordosis when adult.

Effects of 5-hydroxytryptamine uptake blockers on the concentration in brain of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in male rats, pro-oestrous rats and ovariectomized rats treated with oestrogen and progesterone

1985 ◽  
Vol 104 (3) ◽  
pp. 407-413
Author(s):  
A. M. Horn ◽  
A. G. Watts
Keyword(s):  
High Performance ◽  
Preceding Paper ◽  
Prolactin Secretion ◽  
Female Rats ◽  
Male Rats ◽  
Raphe Nuclei ◽  
Ovariectomized Rats ◽  
Hydroxyindoleacetic Acid ◽  
Raphé Nuclei ◽  
The Brain

ABSTRACT The aim of this study was to determine the effect of 5-hydroxytryptamine (5-HT) uptake blockade on 5-HT turnover by measuring the concentrations of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in brain with the aid of high performance liquid chromatography and electrochemical detection. The indoleamines were measured in the anterior hypothalamus (AH), posterior hypothalamus (PH) and raphe nuclei 30 min after the i.v. injection of either alaproclate (30 mg/kg) or zimelidine (20 mg/kg). The effect of alaproclate was studied in male rats, pro-oestrous female rats, rats ovariectomized and injected s.c. with 20 μg oestradiol benzoate (OB) on dioestrus and at 12.00 h of the next day (presumptive pro-oestrus) with 2 mg progesterone (model 1) and rats ovariectomized 3–4 weeks before an s.c. injection of 20 μg OB followed 72 h later by an s.c. injection of 2 mg progesterone (model 2). Alaproclate caused a significant decrease in the 5-HIAA/5-HT ratio in the AH and PH of the brain of male rats, in the PH and raphe nuclei in pro-oestrous rats and model 1, and in the raphe nuclei alone in model 2. Zimelidine had no effect on the 5-HIAA/5-HT ratio in any area in model 2. In male rats the injection of parachlorophenylalanine produced a marked reduction in the brain concentrations of 5-HT and 5-HIAA, but the 5-HIAA/5-HT ratio was unchanged by a subsequent injection of alaproclate. None of the pharmacological agents affected significantly the brain concentrations of noradrenaline, dopamine or dihydroxyphenylacetic acid. These results together with the data in the preceding paper show that in female rats changes in LH and prolactin secretion produced by alaproclate may reflect changes in central 5-HT turnover. J. Endocr. (1985) 104, 407–413

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