Effects of exposure to pups on maternal behaviour, sexual behaviour and serum prolactin concentrations in male rats

1984 ◽  
Vol 102 (1) ◽  
pp. 115-119 ◽  
Author(s):  
P. Södersten ◽  
P. Eneroth
Keyword(s):  
Dopamine Receptor ◽  
Sexual Behaviour ◽  
Behavioural Response ◽  
Daily Treatment ◽  
Male Rats ◽  
Serum Prolactin ◽  
Maternal Behaviour ◽  
Dopamine Receptor Agonist ◽  
Continuous Exposure ◽  
Rat Pups

ABSTRACT Male rats showed maternal behaviour within 72 h after the onset of continuous exposure to newborn rat pups. The latency of the behavioural response could be reduced by daily treatment with the dopamine receptor antagonist domperidone (2 × 2·5 mg/rat), which increased serum prolactin concentrations (241·4 ± 26·5 (s.e.m.) μg/l) above those of vehicle-treated males exposed to pups (25·3 ± 11·7 μg/l). Male rats did not respond to exposure to pups by secreting prolactin; keeping endogenous prolactin concentrations at a minimum (2·8±0·1 μg/l) by daily treatment with the dopamine receptor agonist bromocriptine (0·5 mg/rat) did not affect the behavioural response of male rats to newborn pups. Neither exposure to pups nor the modest hyperprolactinaemia induced by daily domperidone treatment affected the display of male sexual behaviour by male rats. J. Endocr. (1984) 102, 115–119

Inhibition of sexual behaviour in lactating rats

1983 ◽  
Vol 99 (2) ◽  
pp. 189-197 ◽  
Author(s):  
P. Södersten ◽  
S. Hansen ◽  
P. Eneroth
Keyword(s):  
Dopamine Receptor ◽  
Sexual Behaviour ◽  
Inhibitory Effect ◽  
Daily Treatment ◽  
Female Rats ◽  
Serum Prolactin ◽  
Dopamine Receptor Agonist ◽  
Serum Progesterone ◽  
Behavioural Effects

Treatment with oestradiol benzoate (OB; 2–250 μg) and progesterone (0·5–25 mg) failed to induce sexual behaviour in lactating rats 6 days after parturition. Removal of pups permitted the induction of sexual behaviour by OB and progesterone and the inhibitory effect of the presence of pups was proportional to the number present. Ovariectomy of lactating rats or reduction of serum prolactin levels in intact lactating rats by daily treatment with the dopamine receptor agonist bromocriptine (0·5 mg/day) permitted the induction of sexual behaviour despite the presence of suckling pups. Removal of pups from lactating rats and subsequent maintenance of high prolactin levels by daily treatment with the dopamine receptor antagonist domperidone (2·5 mg/day) maintained the state of refractoriness to the behavioural effects of OB and progesterone provided that the ovaries remained in situ. Inhibition of sexual behaviour in lactating rats could be maintained after ovariectomy by implantation of progesterone-filled, but not androgen-filled implants at the time of ovariectomy. Removal of the pups or reduction of prolactin levels by bromocriptine treatment permitted the induction of sexual behaviour by OB in ovariectomized progesterone-implanted lactating rats. Inhibition of the behaviour in ovariectomized progesterone-implanted lactating rats could be maintained after pup removal by daily domperidone treatment. Continuously raised serum progesterone or prolactin levels have no effect on the induction of sexual behaviour in female rats but the present data suggest that during lactation progesterone and prolactin act in synergy to inhibit the behaviour.

Sex differences in behavioural androgen sensitivity: possible role of androgen metabolism

1984 ◽  
Vol 100 (2) ◽  
pp. 245-248 ◽  
Author(s):  
A. Mode ◽  
J.-Å. Gustafsson ◽  
P. Södersten ◽  
P. Eneroth
Keyword(s):  
Sex Difference ◽  
Sexual Behaviour ◽  
Behavioural Response ◽  
Female Rats ◽  
Male Rats ◽  
Androgen Metabolism ◽  
Target Organs ◽  
Androgen Sensitivity ◽  
Masculine Sexual Behaviour

ABSTRACT Masculine sexual behaviour was induced in castrated sexually inactive but experienced male rats by testosterone-filled constant-release implants or daily injections of the synthetic androgen 17β-hydroxy-17α-methyl-estra-4,9,11-triene-3-one (methyltrienolone, R 1881), which resists metabolism by target organs. Feminization of the hepatic androgen metabolism by subcutaneous implantation of osmotic minipumps, which delivered a constant amount of human GH, did not affect the behavioural response of castrated rats to testosterone. Testosterone implants were only minimally effective in inducing male behaviour in ovariectomized female rats, but R 1881 was as effective in stimulating male behaviour in females as in males. Testosterone-treated but not R 1881-treated females showed pronounced female sexual behaviour in response to progesterone treatment despite the absence of measureable amounts of oestradiol-17β in peripheral blood. The results provide evidence that masculine sexual behaviour can be activated by an androgen in the absence of oestrogenic stimulation and suggest that the sex difference in the behavioural response to testosterone may be due to a sex difference in the metabolism of androgens by the brain. J. Endocr. (1984) 100, 245–248

Stress-induced prolactin release in female, male and androgenized rats: influence of progesterone treatment

1986 ◽  
Vol 110 (3) ◽  
pp. 423-428 ◽  
Author(s):  
G. A. Jahn ◽  
R. P. Deis
Keyword(s):  
Luteal Phase ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Serum Prolactin ◽  
Maternal Behaviour ◽  
Stress Exposure ◽  
Control Groups ◽  
Prolactin Release ◽  
Serum Progesterone

ABSTRACT Ether stress applied at 10.00 h induced a 100% increase in serum prolactin in intact and ovariectomized androgenized rats. Ovariectomy significantly diminished the basal serum prolactin values observed in intact androgenized rats. Two doses of progesterone (5 mg) given to intact and ovariectomized androgenized rats 14 and 2 h before exposure to ether stress increased prolactin values in the control groups but completely prevented the effect of stress. Exposure to ether stress induced a 100% increase in serum prolactin values in androgenized rats with increased serum progesterone levels 4 days after the induction of ovulation and the luteal phase with human chorionic gonadotropin (hCG). A group of androgenized rats with induced maternal behaviour and which had been suckled for 6 days was given 100 i.u. hCG and suckled for another 6 days after the hCG-induced luteal phase had been established. The serum prolactin and progesterone values of these rats were significantly higher than those treated with hCG only and ether stress did not increase prolactin release. A greatly increased serum concentration of prolactin was obtained in pro-oestrous and oestrous virgin rats after exposure to ether stress. Serum prolactin was also increased by stress in male rats. Progesterone administration to these female and male rats prevented stress-induced prolactin release. To ascertain the part played by dopamine and serotonin in the effect of stress on prolactin release, groups of androgenized and oestrous female rats were treated with bromocriptine or p-chlorophenylalanine methylester hydrochloride (pCPA). The dopaminergic agonist bromocriptine markedly reduced prolactin levels in the unstressed androgenized rats, but did not prevent the prolactin increases induced by stress. Administration of pCPA had no effect on basal or stress-increased serum levels of prolactin. It is concluded that modifications of the ovarian steroid secretions, especially of progesterone, has profound effects on prolactin release in response to ether stress. The release of the hormone was not mediated by a dopaminergic or serotonergic regulatory pathway. J. Endocr. (1986) 110, 423–428

scholarly journals Prolactin-Secreting Leiomyoma Causing Hyperprolactinaemia Unresponsive to Dopamine Agonist Therapy and Resolution following Myomectomy

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Lucinda Barry ◽  
Selvan Pather ◽  
Ash Gargya ◽  
Anthony Marren
Keyword(s):  
Dopamine Agonist ◽  
Dopamine Receptor ◽  
Uterine Fibroid ◽  
Receptor Agonist ◽  
Uterine Leiomyoma ◽  
Serum Prolactin ◽  
Dopamine Receptor Agonist ◽  
Agonist Therapy ◽  
Dopamine Agonist Therapy ◽  
Future Fertility

Prolactin-secreting leiomyomas are rare, with only eight cases reported in the literature. This case describes a 37-year-old female with hyperprolactinaemia (1846 mIU/L; 85–500 mIU/L) refractory to cabergoline causing infertility and galactorrhea. MRI pituitary was normal. The patient had a known enlarging uterine leiomyoma on serial pelvic ultrasounds (15.2 cm × 9.1 cm × 12.1 cm). The serum prolactin returned to subnormal levels two days postmyomectomy and showed recovery to normal levels in the months following surgery. Immunostaining of the leiomyoma for prolactin was negative. Despite not staining for prolactin, quick resolution of the patient’s hyperprolactinaemia after myomectomy supports the diagnosis of a prolactin-secreting fibroid. A prolactin-secreting leiomyoma should be considered in patients with hyperprolactinaemia and normal pituitary MRI which is refractory to dopamine receptor agonist therapy who also have evidence of a uterine fibroid. In patients wishing to seek fertility, myomectomy should be considered to allow for normal ovulation and possibility of future fertility.

Evidence that prolactin does not affect the induction of sexual behaviour by oestradiol and progesterone in ovariectomized rats

1983 ◽  
Vol 99 (2) ◽  
pp. 181-187 ◽  
Author(s):  
P. Södersten ◽  
S. Hansen ◽  
P. Eneroth
Keyword(s):  
Receptor Antagonist ◽  
Dopamine Receptor ◽  
Sexual Behaviour ◽  
Inhibitory Effect ◽  
Ovariectomized Rats ◽  
Serum Prolactin ◽  
Behavioural Effect ◽  
Dopamine Receptor Antagonist ◽  
Oestradiol Benzoate ◽  
Acute Increase

Injection of 2·5 mg of the dopamine receptor antagonist domperidone raised serum prolactin concentrations within 3 h and high prolactin levels were maintained for 12 h in ovariectomized rats pretreated with 2 μg oestradiol benzoate (OB). This dose of domperidone stimulated the display of sexual behaviour in ovariectomized OB-treated rats within 3 h of administration. The behavioural effect of domperidone, but not its effect on serum prolactin concentrations, was blocked by adrenalectomy. Daily treatment with domperidone had no inhibitory effect on the subsequent induction of sexual behaviour by OB and progesterone in ovariectomized rats. A slight facilitation of the behaviour was noticed in OB-treated rats given daily domperidone injections, but this effect was cancelled by adrenalectomy. The results suggest that an acute increase in serum prolactin levels has no effect on the induction of sexual behaviour by OB in itself, but can stimulate the secretion of an adrenal product, perhaps progesterone, which facilitates the behaviour. Similarly, constant high levels of prolactin by themselves have no effect on the subsequent induction of sexual behaviour by OB and progesterone.

Toxic effects of inhaled DMMP on the kidneys of Fischer-344 rats

1987 ◽  
Vol 45 ◽  
pp. 880-881
Author(s):  
D.R. Mattie ◽  
C.J. Hixson
Keyword(s):  
Left Kidney ◽  
Inhalation Exposure ◽  
Electron Microscopic Examination ◽  
Exposure Period ◽  
Male Rats ◽  
Continuous Exposure ◽  
Fischer 344 Rats ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Fischer 344

Dimethylmethylphosphonate (DMMP) is a simple organophosphate used industrially as a flame retardant and to lower viscosity in polyester and epoxy resins. The military considered the use of DMMP as a nerve gas simulant. Since military use of DMMP involved exposure by inhalation, there was a need for a subchronic inhalation exposure to DMMP to fully investigate its toxic potential.Male Fischer-344 rats were exposed to 25 ppm or 250 ppm DMMP vapor on a continuous basis for 90 days. An equal number of control rats were sham-exposed. Following the 90-day continuous exposure period, 15 male rats were sacrificed from each group. Two rats from each group had the left kidney perfused for electron microscopic examination. The kidneys were perfused from a height of 150 cm water with 1% glutaraldehyde in Sorensen's 0.1M phosphate buffer pH 7.2. An additional kidney was taken from a rat in each group and fixed by immersion in 2.5% glutaraldehyde and 2% paraformaldehyde in 0.1M cacodylate buffer pH 7.4. A portion of the 9 kidneys collected for electron microscopy were processed into Epon 812. Thin sections, stained with uranyl acetate and lead citrate, were examined with a JEOL 100B Transmission Electron Microscope. Microvilli height was measured on photographs of the cells of proximal tubules. This data, along with morphologic features of the cells, allows the proximal convoluted tubules (PCT) to be identified as being S1, S2, or S3 segment PCT.

Do similar neural systems subserve aggressive and sexual behaviour in male rats? Insights from c-Fos and pharmacological studies

2005 ◽  
Vol 526 (1-3) ◽  
pp. 226-239 ◽  
Author(s):  
Jan G. Veening ◽  
Lique M. Coolen ◽  
Trynke R. de Jong ◽  
Henk W. Joosten ◽  
Sietze F. de Boer ◽  
...  
Keyword(s):  
Sexual Behaviour ◽  
Male Rats ◽  
Neural Systems ◽  
Pharmacological Studies

Changes in Pituitary-Adrenal Function under Continuous Exposure to Hypoxia in Male Rats

2009 ◽  
Vol 81 (01) ◽  
pp. 65-70 ◽  
Author(s):  
M. Mohri ◽  
K. Seto ◽  
M. Nagase ◽  
K. Tsunashima ◽  
M. Kawakami
Keyword(s):  
Adrenal Function ◽  
Male Rats ◽  
Continuous Exposure
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