PERIPHERAL AND CENTRAL ANDROGENIC STIMULATION OF SEXUAL BEHAVIOUR OF CASTRATED MALE RATS

1977 ◽  
Vol 84 (4) ◽  
pp. 813-828 ◽  
Author(s):  
Rachel Hamburger-Bar ◽  
Henk Rigter
Keyword(s):  
Sexual Behaviour ◽  
Testosterone Propionate ◽  
Male Rats ◽  
Peripheral Target ◽  
Peripheral Tissues ◽  
Target Organs ◽  
The Brain ◽  
Stimulation Of ◽  
Maintenance Study

ABSTRACT The effects of androgens on the maintenance and restoration of sexual behaviour (mounts, intromissions and ejaculations) of castrated male rats were studied. In the maintenance study the rats were treated during 5 weeks, starting one day following castration. Testosterone propionate maintained sexual behaviour at an almost normal level. The androgenoestrogen intermediate 19-hydroxytestosterone propionate was unable to prevent the decline in the number of ejaculations over the weeks although this hormone maintained the post-ejaculatory refractory period in those rats that ejaculated and also maintained normal sexual latencies. In the restoration study administration of testosterone propionate during 7 weeks to long-term castrated rats restored sexual behaviour to normal. 19-Hydroxytestosterone propionate treated rats displayed mounts but no other signs of sexual behaviour. The 5α-reduced androgen dihydrotestosterone propionate did not restore sexual behaviour. Testosterone propionate and dihydrotestosterone propionate stimulated peripheral target organs; 19-hydroxytestosterone propionate was ineffective in this respect. It has been suggested that testosterone might stimulate sexual behaviour in rats in two ways, i. e., via its aromatization to oestradiol in the brain, and by stimulating growth of peripheral tissues via its 5α-reduction to dihydrotestosterone. In support for this view we have found that the combination of 19-hydroxytestosterone propionate and dihydrotestosterone propionate was effective in restoring the full pattern of sexual behaviour in castrated male rats.

EFFECTS OF 17β-HYDROXY-4-ANDROSTEN-19-OL-3-ONE (19-HYDROXYTESTOSTERONE) AND 5α-ANDROSTAN-17β-OL-3-ONE (DIHYDROTESTOSTERONE) ON ASPECTS OF SEXUAL BEHAVIOUR IN CASTRATED MALE RATS

1974 ◽  
Vol 61 (1) ◽  
pp. 105-115 ◽  
Author(s):  
R. F. PARROTT
Keyword(s):  
Adult Male ◽  
Sexual Behaviour ◽  
Testosterone Propionate ◽  
Male Rats ◽  
Organ Weights ◽  
Refractory Periods ◽  
Peripheral Effect ◽  
Rate Of Decline ◽  
The Brain ◽  
Experienced Adult

SUMMARY The ability of 19-hydroxytestosterone propionate (150 μg/day) to maintain sexual behaviour, accessory organ weights and the number of penile spines in experienced adult male rats in the 5 weeks after castration was compared with intact males and castrated animals receiving testosterone propionate (75 μg/day) or oil treatment. In a second experiment a group of male rats receiving dihydrotestosterone propionate (150 μg/day) was also included. 19-Hydroxytestosterone did not maintain ejaculatory performance but animals that ejaculated had refractory periods similar to those in intact and testosterone-treated groups. Dihydrotestosterone, however, slowed the rate of decline of ejaculatory performance but the refractory periods were comparable to those in castrated controls. The former action of dihydrotestosterone was attributed to its stimulatory effect on peripheral structures, especially the penile spines. 19-Hydroxytestosterone was shown to have no peripheral effect at doses up to 1800 μg every other day. The results are discussed in terms of a theory of testosterone action involving aromatization in the brain and 5α-reduction peripherally.

Prolonged retention of the anorectic cobalt protoporphyrin in the hypothalamus and the resulting expression of Fos

2004 ◽  
Vol 287 (2) ◽  
pp. R465-R471 ◽  
Author(s):  
Richard A. Galbraith ◽  
Ilean Hodgdon ◽  
Michele S. Grimm ◽  
Margaret A. Vizzard
Keyword(s):  
Male Rats ◽  
Halothane Anesthesia ◽  
Short Term ◽  
Brain Areas ◽  
Duration Of Action ◽  
Prolonged Duration ◽  
Cobalt Protoporphyrin ◽  
Prolonged Retention ◽  
The Brain

The anorectic cobalt protoporphyrin (CoPP) is known to elicit short-term hypophagia and long-term weight loss through unknown mechanisms in the brains of experimental animals. The goal of this work was to determine 1) if the prolonged duration of action of CoPP is related to its prolonged retention within the brain; and 2) with the use of immunohistochemical detection of Fos, the product of the early-immediate gene c-fos, which cells are activated after exposure to CoPP. These studies were carried out in male rats after intracerebroventricular administration of CoPP, 0.4 μmol/kg body wt, given under light halothane anesthesia. Residence of CoPP in the brain was determined by residual counts in dissected brains of 57CoPP-injected rats. Fos immunoreactivity was mapped in coronal sections of rat brains 4–6 h after injection with CoPP. The results showed that 57CoPP was retained in the hypothalamus preferentially compared with the cortex of the brain and could be detected in the hypothalamus for in excess of 5 wk. Fos activation was increased by CoPP, detected predominantly in neuronal rather than glial cells, and was markedly more robust in the hypothalamus than in other brain areas. Thus CoPP remains in the hypothalamus for prolonged periods and activates Fos expression in the hypothalamus.

Endotoxin-Induced Uveitis Causes Long-Term Changes in Trigeminal Subnucleus Caudalis Neurons

2005 ◽  
Vol 94 (6) ◽  
pp. 3815-3825 ◽  
Author(s):  
David A. Bereiter ◽  
Keiichiro Okamoto ◽  
Akimasa Tashiro ◽  
Harumitsu Hirata
Keyword(s):  
Ocular Surface ◽  
Receptive Fields ◽  
Male Rats ◽  
Cervical Cord ◽  
Single Exposure ◽  
Eye Blinks ◽  
Long Term Changes ◽  
Trigeminal Subnucleus Caudalis ◽  
Stimulation Of

Endotoxin-induced uveitis (EIU) is commonly used in animals to mimic ocular inflammation in humans. Although the peripheral aspects of EIU have been well studied, little is known of the central neural effects of anterior eye inflammation. EIU was induced in male rats by endotoxin or lipopolysaccharide (LPS, 1 mg/kg ip) given 2 or 7 days earlier. Neurons responsive to mechanical stimulation of the ocular surface were recorded under barbiturate anesthesia at the trigeminal subnucleus interpolaris/caudalis (Vi/Vc) transition and subnucleus caudalis/cervical cord (Vc/C1) junction, the main terminal regions for corneal nociceptors. Two days after LPS, Vc/C1 units had reduced responses to histamine, nicotine, and CO2 gas applied to the ocular surface, whereas unit responses were increased 7 days after LPS. Those units with convergent cutaneous receptive fields at Vc/C1 were enlarged 7 days after LPS. Units at the Vi/Vc transition also had reduced responses to histamine and CO2 2 days after LPS but no enhancement was seen at 7 days. Tear volume evoked by CO2 was reduced 2 days after LPS and returned toward control values by 7 days, whereas CO2-evoked eye blinks were normal at 2 days and increased 7 days after LPS. These results indicate that a single exposure to endotoxin causes long-term changes in the excitability of second-order neurons responsive to noxious ocular stimulation. The differential effects of EIU on tear volume and eye blink lend further support for the hypothesis that ocular-sensitive neurons at the Vi/Vc transition and Vc/C1 junction regions mediate different aspects of pain during intraocular inflammation.

Spinal and Supraspinal Effects of Long-Term Stimulation of Sensorimotor Cortex in Rats

2007 ◽  
Vol 98 (2) ◽  
pp. 878-887 ◽  
Author(s):  
Xiang Yang Chen ◽  
Shreejith Pillai ◽  
Yi Chen ◽  
Yu Wang ◽  
Lu Chen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Operant Conditioning ◽  
Sensorimotor Cortex ◽  
H Reflex ◽  
Freely Moving ◽  
Activity Dependent ◽  
Spinal Cord Function ◽  
The Brain ◽  
Stimulation Of

Sensorimotor cortex (SMC) modifies spinal cord reflex function throughout life and is essential for operant conditioning of the H-reflex. To further explore this long-term SMC influence over spinal cord function and its possible clinical uses, we assessed the effect of long-term SMC stimulation on the soleus H-reflex. In freely moving rats, the soleus H-reflex was measured 24 h/day for 12 wk. The soleus background EMG and M response associated with H-reflex elicitation were kept stable throughout. SMC stimulation was delivered in a 20-day-on/20-day-off/20-day-on protocol in which a train of biphasic 1-ms pulses at 25 Hz for 1 s was delivered every 10 s for the on-days. The SMC stimulus was automatically adjusted to maintain a constant descending volley. H-reflex size gradually increased during the 20 on-days, stayed high during the 20 off-days, and rose further during the next 20 on-days. In addition, the SMC stimulus needed to maintain a stable descending volley rose steadily over days. It fell during the 20 off-days and rose again when stimulation resumed. These results suggest that SMC stimulation, like H-reflex operant conditioning, induces activity-dependent plasticity in both the brain and the spinal cord and that the plasticity responsible for the H-reflex increase persists longer after the end of SMC stimulation than that underlying the change in the SMC response to stimulation.

Changes in Sleep Architecture under Sustained Pain in Adult Male Rats Subjected to Neonatal Short-Lasting Local Inflammatory Insult

2017 ◽  
Vol 39 (5) ◽  
pp. 386-398
Author(s):  
Cheryl C.H. Yang ◽  
Shiang-Suo Huang ◽  
Chun-Ting Lai ◽  
Terry B.J. Kuo ◽  
Ya-Chun Chu
Keyword(s):  
Paradoxical Sleep ◽  
Sleep Architecture ◽  
Male Rats ◽  
Intraplantar Injection ◽  
Quiet Sleep ◽  
Adult Rats ◽  
Physiological Relevance ◽  
Highly Correlated ◽  
Stimulation Of

Neonatal, short-lasting, local, nociceptive insult by carrageenan can cause long-term alterations in somatosensory and neurohumoral systems. We previously revealed hyporesponsiveness of the autonomic nervous system (ANS) after painful stimulation of adult rats in a neonatal carrageenan-induced pain model. Sleep disturbance has been highly correlated with pain and ANS activity. In the present study, adult rats that had received an intraplantar injection of carrageenan on postnatal day 1 were investigated to determine if there were alterations in their sleep architecture upon the stimulation of pain. Polysomnographic and heart rate variability recordings were carried out, with a wireless transmission of data, for 24 h under baseline conditions and after an intraplantar injection of complete Freund's adjuvant to induce sustained nociception. Increased active awake (AW) and decreased quiet sleep (QS) and paradoxical sleep (PS) times were noted in the control animals. In the carrageenan-treated rats, the AW time increased but with decreased alertness, as revealed by decreases in beta and increases in theta power. The QS time did not decrease. The PS time decreased during the first 12 h, then increased during the following 12 h, suggesting an early rebound of formerly deprived PS time. Sympathetic activation under sustained pain was not apparent in any stage of sleep in carrageenan-treated rats and was even suppressed in AW time. An impaired sympathetic reaction to pain may have contributed to the atypical changes in sleep architecture in these rats. In conclusion, pain in early life has a long-term effect on the cardiovascular-autonomic-electroencephalographic responses to pain later in life. The physiological relevance of these results remains undetermined.

THE EFFECTS OF ANDROGENIZATION IN MALE RATS CASTRATED AT BIRTH

1966 ◽  
Vol 34 (1) ◽  
pp. 117-123 ◽  
Author(s):  
R. L. MORRISON ◽  
D. C. JOHNSON
Keyword(s):  
Testosterone Propionate ◽  
Subsequent Treatment ◽  
Male Rats ◽  
Androgen Treatment ◽  
Target Organs ◽  
Accessory Sex Organs ◽  
Increased Sensitivity ◽  
Excessive Secretion

SUMMARY Male rats were castrated on the day of birth and 5 days later half were given 2·5 mg. testosterone propionate (TP) subcutaneously (androgenization). When 30 days old, single animals were treated with graded doses of TP for 10 days. At the same time 57 males were united in parabiosis with normal intact males, and treated for 10 days with androgen. Androgenization resulted in increased sensitivity of the accessory sex organs to subsequent treatment with TP. Also, the excessive secretion of gonadotrophin by the castrated animals, as measured by androgen production in intact parabiotic partners, was more effectively inhibited by TP in androgenized than in non-androgenized males. The results are consistent with the interpretation that early androgen treatment sensitizes both the male target organs and the hypothalamo-hypophysial system to androgen.

FAILURE OF DIHYDROTESTOSTERONE TO ELICIT SEXUAL BEHAVIOUR IN THE FEMALE CAT

1977 ◽  
Vol 75 (1) ◽  
pp. 173-174 ◽  
Author(s):  
VERONICA A. CERNY
Keyword(s):  
Sexual Behaviour ◽  
Female Rats ◽  
University Of Pennsylvania ◽  
Male Rat ◽  
Peripheral Target ◽  
Target Tissue ◽  
Male And Female ◽  
Behavioural Effects ◽  
Male And Female Rats ◽  
Target Organs

Laboratory of Anatomy, Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A. (Received 28 March 1977) Testosterones have stimulatory effects on peripheral target tissue and sexual behaviour in male and female rats (Beach, 1942), guinea-pigs (Young, 1961; Diamond & Young, 1963), rabbits (Palka & Sawyer, 1966; Beyer & Rivaud, 1973) and cats (Green, Clemente & de Groot, 1957; Young, 1961; Whalen & Hardy, 1970). 5α-Androstan-17β-ol-3-one (dihydrotestosterone, DHT) has stimulatory effects on peripheral target organs, and like testosterones, a negative feedback effect on the pituitary gland and hypothalamus (Feder, 1971). No behavioural effects were seen in male or female rats when DHT was injected systemically (Beyer, Morali & Cruz, 1971; Feder, 1971) nor in the male rat when it was administered intracerebrally (Johnston & Davidson, 1972). Many experiments support the hypothesis that only androgens that can be aromatized to oestrogens can elicit sexual behaviour and

EFFECT OF CYPROTERONE ACETATE ON SEXUAL DIMORPHISM OF THE EXORBITAL LACRIMAL GLAND IN RATS

1969 ◽  
Vol 45 (3) ◽  
pp. 421-NP ◽  
Author(s):  
J. D. HAHN
Keyword(s):  
Sexual Dimorphism ◽  
Histological Examination ◽  
Lacrimal Gland ◽  
Sexual Behaviour ◽  
Cyproterone Acetate ◽  
Testosterone Propionate ◽  
Considerable Extent ◽  
Male Rats ◽  
Substitution Treatment ◽  
End Of Treatment

SUMMARY Adult male rats were treated with daily s.c. doses of 10 mg. cyproterone acetate for 3 weeks. Histological examination of the exorbital lacrimal glands at the end of treatment showed distinct differences compared with male controls: the histological picture showing greater resemblance to the glands of female controls. In orchidectomized rats receiving substitution treatment with testosterone propionate, cyproterone acetate 'neutralized' the effect of testosterone propionate on the exorbital lacrimal gland to a considerable extent. The possibility that this gland may play a part in the sexual behaviour of the rat is discussed.

THE COMPARATIVE ACTIONS OF TESTOSTERONE PROPIONATE AND 5α-ANDROSTAN17β-OL-3-ONE PROPIONATE ON THE REPRODUCTIVE BEHAVIOUR, PHYSIOLOGY AND MORPHOLOGY OF MALE RATS

1971 ◽  
Vol 51 (2) ◽  
pp. 241-NP ◽  
Author(s):  
H. H. FEDER
Keyword(s):  
Body Weight ◽  
Seminal Vesicle ◽  
Sexual Behaviour ◽  
Testosterone Propionate ◽  
Reproductive Behaviour ◽  
Male Rats ◽  
Male Sexual Behaviour ◽  
Testicular Weight ◽  
Seminal Vesicle Weight ◽  
Experienced Adult

SUMMARY 5α-Androstan-17β-ol-3-one in its free or in its propionate form was injected systemically (125 μg/day/rat) into sexually experienced, adult, castrated, male rats. These compounds were ineffective in activating masculine behaviour patterns, despite having measurable effects on body weight, seminal vesicle weight and penile morphology. The propionate form also had strong anti-gonadotrophic properties, since when it was injected for 6 days into intact, immature, male rats it significantly reduced testicular weight. In contrast, testosterone propionate (125 μg/day/rat) restored male sexual behaviour to the levels found before castration when injected systemically. Testosterone propionate also affected body weight, seminal vesicle weight, penile morphology and the testicular weight of immature males. These effects may have been due in part to conversion of testosterone to 5α-androstan-17β-ol-3-one, but this metabolic step does not seem to be obligatory for activation of male sexual behaviour in rats.

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

Sign in / Sign up

Export Citation Format

Share Document