The activation of sexual behaviour by hypothalamic implants of oestrogen

Harris, G. W.; Michael, R. P.

doi:10.1113/jphysiol.1964.sp007377

Cited by 75 publications

(20 citation statements)

References 23 publications

(39 reference statements)

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“…The hypothesis that endogenous progesterone participates in the induction of spontaneous oestrous behaviour has been regarded as uncertain because the onset of cyclical sexual activity precedes ovulation and the pre-ovulatory ovary of several mammals has been shown to produce little progesterone (see Short, 1967). Moreover, progesterone may not be essential to the induction of oestrus (dog: Leathern, 1938; cat: Harris & Michael, 1964;rat: Lisk, 1965), and it may, in fact, have effects ant¬ agonistic to the display of sexual receptivity (Marshall & Hammond, 1945;Baker, Ulberg, Grummer & Casida, 1954;Goy, Phoenix & Young, 1966).…”

Section: Introductionmentioning

confidence: 98%

Progesterone Concentrations in the Arterial Plasma of Guinea-Pigs During the Oestrous Cycle

Feder¹,

Resko²,

Goy³

1968

Journal of Endocrinology

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The quantities of circulating progesterone and its 20-dihydro metabolites in cyclic female guinea-pigs were estimated by gas chromatography with electron capture detection. Forty-four animals were divided into 13 groups of approximately equal size according to stage of the oestrous cycle. The day on which a lordosis response could be elicited was designated Day 0 of the cycle. In the first few hours of sexual receptivity on Day 0 progesterone levels were 0\m=.\36\ m=+-\ 0\m=.\07 \g=m\g./100 ml. arterial plasma. The ovaries were pre-ovulatory at this stage. After 5 to 12 hr. of behavioural receptivity progesterone levels dropped to 0\m=.\04 \m=+-\0\m=.\01\g=m\g./100 ml. plasma, and at the termination of receptivity (just after ovulation) progesterone was almost completely undetectable.The concentration of progesterone increased gradually after ovulation reaching a peak about Day 9 (0\m=.\30 \ m=+-\ 0\m=.\05 \g=m\g./100 ml. plasma) and then fell to undetectable levels by Day 15. The 20-dihydro metabolites of progesterone were not present in significant quantities at any stage of the cycle.It is concluded that in guinea-pigs a surge of progesterone occurs approximately 8 to 12 hr. before ovulation and coincides with the onset of oestrous behaviour. The plasma concentration of progesterone at this pre-ovulatory stage is at least as high as that measured at any point during the luteal phase.

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Section: Introductionmentioning

confidence: 98%

Progesterone Concentrations in the Arterial Plasma of Guinea-Pigs During the Oestrous Cycle

Feder¹,

Resko²,

Goy³

1968

Journal of Endocrinology

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“…Subsequent work in 1964-65 was supported by USPHS Grant HD 00778 to the author. centers to activate the mating pattern in female cats (3) and rats (4). In the male it would appear a priori to be less likely that sexual behavior is the result of the direct effect of testosterone on a discrete cerebral center, since successful mating in this sex depends upon a highly co-ordinated series of activities rather than a relatively simple reflex lordosis as in the female.…”

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confidence: 98%

Activation of the Male Rat's Sexual Behavior by Intracerebral Implantation of Androgen

Davidson

1966

Endocrinology

342

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The hypothesis that sexual behavior in the male results from the direct action of testosterone on specific brain regions was tested, using intracerebral implantation of crystalline testosterone propionate in castrate male rats. Following establishment of a criterion for the loss of sex behavior in castrates, it was determined that the minimum effective dose of subcutaneously administered testosterone for stimulation of the accessory sex glands was less than that required for restoration of sex behavior. It was found that intracerebral implantation of testosterone could result in reappearance of the complete pattern of male sexual behavior in the absence of any histologically demonstrable stimulation of the seminal vesicles or prostate. These results never followed the implantation of cholesterol, showing that they were not due to lesion production by the implant. Although occasional responses were found following implants in other areas of the brain, all the most effective implants were in the hypothalamic-preoptic region, with the most consistent behavioral reactivation resulting from medial preoptic implants. It is concluded that sexual behavior in the male may be virtually completely independent of androgen-sensitive peripheral mechanisms, and that it is dependent upon activation by testosterone of structures lying within the hypothalamicpreoptic region of the brain. (Endocrinology 79: 783, 1966)

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“…Harris, Michael & Scott (1958) and Harris & Michael (1964) have shown that oestrogen acts directly on the hypothalamus to produce oestrous behaviour. Meyerson (1964) and Lindstrom & Meyerson (1966) have reported that in ovariectomized rats both adrenergic and cholinergic drugs can modify the oestrous response to steroid hormones, and it is assumed that these drugs act by modifying the central nervous functions that produce oestrous behaviour.…”

mentioning

confidence: 98%

The Pharmacological Blockade of the Initiation but Not of the Maintenance of Sexual Receptivity of the Ewe

Buttle¹,

Robertson²

1967

Journal of Endocrinology

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1965) have shown that chlorpromazine effectively blocks ovulation in the ewe when administered immediately after the animals had become sexually receptive. From the results of Robertson & Rakha (1966) it appears that the suppressive action of chlorpromazine was very likely related to the blockade of the ovulatory release of luteinizing hormone (LH) that occurs at this time. Their results indicate also that there is a discharge of follicle-stimulating hormone (FSH) from the pituitary prior to oestrus, and it can be postulated that it is this discharge that precipitates the onset of oestrus. It was of interest to determine whether chlorpromazine when given over the normal period of release of FSH would block the onset of sexual receptivity in the ewe.Twelve intact, cyclic, Cheviot ewes were maintained under prolonged (72 hr.) sedation with chlorpromazine, the treatment starting at the beginning of the 15th day of the cycle, i.e. 36 hr. before the time of the expected onset of sexual receptivity, and ending 36 hr. after. An initial i.m. dose of 12 mg. chlorpromazine/kg. was given, followed by 4 mg./kg. i.m., every 6 hr. None of the 12 ewes showed oestrous behaviour during the period of sedation, i.e. the 15th-18th day of the cycle.Although the failure of the animals to come into oestrus could be attributed to a block in the mechanism leading to the release of the oestrus-inducing pituitary gonadotrophin(s), it was realized that chlorpromazine might also block the ability of oestrogen itself to induce behavioural oestrus. It was decided to test whether chlorpromazine inhibits the onset of oestrus, in oestrogen-treated, ovariectomized ewes.Six ovariectomized ewes were treated with progesterone for 12 days (20 mg. i.m. every 2 days) followed by a single i.m. injection of 25 pg. 17/?-oestradiol monobenzoate 48 hr. after the last dose of progesterone. Five of the six ewes showed oestrous behaviour, i.e. they accepted mating 22-36 hr. after the injection of oestradiol. One ewe remained anoestrous and was discarded. After a week's rest the remaining five ovariectomized ewes received the same steroid treatment, with chlorpromazine sedation from 18-22 hr. before, until 48 hr. after, the oestradiol injection. An initial * Present address :

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The activation of sexual behaviour by hypothalamic implants of oestrogen

Cited by 75 publications

References 23 publications

Progesterone Concentrations in the Arterial Plasma of Guinea-Pigs During the Oestrous Cycle

Progesterone Concentrations in the Arterial Plasma of Guinea-Pigs During the Oestrous Cycle

Activation of the Male Rat's Sexual Behavior by Intracerebral Implantation of Androgen

The Pharmacological Blockade of the Initiation but Not of the Maintenance of Sexual Receptivity of the Ewe

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