scholarly journals Stimulation of the corpora lutea of the rat by means of progesterone and testosterone

1937 ◽  
Vol 124 (836) ◽  
pp. 362-368 ◽  
Keyword(s):  
Guinea Pigs ◽  
Rhesus Monkeys ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Corpora Lutea ◽  
Normal Female ◽  
Once Daily ◽  
Black And White ◽  
White Rats ◽  
Stimulation Of

The administration of progestin or progesterone inhibits oestrus in normal female experimental animals and leads to the cessation of follicular growth (Papanicolaou 1926, working on guinea-pigs; Gley 1928, on rats; Corner 1935, on monkeys). Active testicular extracts or testosterone have a similar effect (Ihrke and D’Amour 1931; Lendle 1931; and Robson 1936, working on rats; Zuckerman 1937, on rhesus monkeys). There is evidence that a phase of luteal activity occurs whenever the ripening of follicles is inhibited (see Evans 1928; Weichert 1930, amongst others), and it was therefore of interest to enquire whether or not luteinization of the ovaries is also an effect of the administration of progesterone and testosterone to normally cyclic female rats. Previous reports on this question are negative. Papanicolaou (1926) observed degenerative changes in the ovaries of guinea-pigs in which several successive oestrous cycles had been suppressed by means of progestin. Selye, Browne and Collip (1936) injected six rats with 4 mg. of progesterone for 12 days, and at the close of the experiment found that neither recent corpora lutea nor mature follicles were present in the ovaries. Albino and black and white rats were used. All injections were given once daily and subcutaneously. Oestrone was administered in aqueous solution, and both progesterone and testosterone propionate in oil. At the end of each experiment the uterus and one of the ovaries were fixed in Bouin’s fluid, and after sectioning, stained with haematoxylin and eosin, the ovary being sectioned serially. The second ovary of each animal was fixed in Flemming’s chrome-osmium fluid with acetic acid, and prepared to show osmicated fats according to the technique described by Deanesly (1930). In certain cases, noted below, the uterus was traumatized by the method of Shelesnyak (1933α) (a modification of that of Long and Evans), in order to produce deciduomata.

THE CORPUS LUTEUM-HYPOPHYSIS RELATIONSHIP: THE EFFECT OF PROGESTERONE TREATMENT ON THE RELEASE OF GONADOTROPHINS IN THE RAT

1966 ◽  
Vol 51 (2) ◽  
pp. 231-244 ◽  
Author(s):  
Andrew B. Kaufman ◽  
I. Rothchild
Keyword(s):  
Female Rats ◽  
Ovariectomized Rats ◽  
Corpora Lutea ◽  
Follicle Development ◽  
Significant Elevation ◽  
Once Daily ◽  
Progesterone Treatment ◽  
Gonadotrophin Secretion ◽  
Pituitary Glands ◽  
Weight Method

ABSTRACT The effect of progesterone on pituitary gonadotrophin release has been studied in the rat. Castrated female rats bearing ovarian autotransplants, or unilaterally ovariectomized rats, were given 1 to 5 mg of progesterone daily for intervals from 7 to 28 days, and then killed. The ovaries, uteri, and vaginas were examined grossly and microscopically, and the pituitary glands were assayed for total gonadotrophin content by the mouse uterine weight method. Although treatment with 5 mg of progesterone for 28 days inhibited ovulation, it did not prevent Graafian follicle development (determined histologically) or secretory function (evaluated by the presence of vaginal mucification) in either of the animal preparations. Progesterone treatment was associated with a significant elevation of pituitary gonadotrophic potency in the castrated rats bearing ovarian autotransplants, but not in the unilaterally ovariectomized rats. These findings suggest that the tonic rate of gonadotrophin secretion is unaffected by treatment with 5 mg of progesterone daily. The acute discharge of the ovulation inducing hormone complex (probably primarily LH) is, however, inhibited by such a dose of progesterone, and probably accounts for the inhibition of ovulation. The findings also suggest that the amount of progesterone secreted by the functioning corpora lutea during pseudopregnancy in the rat is equivalent in effect to between 2 and 5 mg of progesterone injected once daily.

SENSITIVITY OF ANTERIOR HYPOTHALAMIC AREAS TO GONADAL STEROID IMPLANTATION IN ANDROGENIZED FEMALE RATS

1977 ◽  
Vol 74 (2) ◽  
pp. 315-NP ◽  
Author(s):  
A. DANGUY ◽  
J. L. PASTEELS ◽  
F. ECTORS
Keyword(s):  
Single Injection ◽  
Mammary Glands ◽  
Prolactin Secretion ◽  
Female Rats ◽  
Male Rats ◽  
Control Synthesis ◽  
Normal Female ◽  
Immunofluorescence Studies ◽  
Oestradiol Benzoate ◽  
Stimulation Of

A single injection of 1 mg of a complex of testosterone esters on day 5 of life was used to prepare constantly oestrous rats. Such androgenized female rats were then ovariectomized and submitted to stereotaxical implantation of 1 μg oestradiol benzoate, 5 μg testosterone isobutyrate or, as a control, 10 μg cholesterol in the anterior hypothalamic areas. The effects of the steroids on plasma and pituitary FSH and LH were assessed by radioimmunoassay. As reported previously by us in normal female and male rats, the preoptic–suprachiasmatic area (POA) was able to control synthesis and secretion of both gonadotrophins and did not lose its sensitivity to oestradiol and testosterone in androgenized rats. Evidence for enhanced prolactin secretion in androgenized rats was derived from immunofluorescence studies of the pituitary gland and from histology of the mammary glands. In this respect the condition of the androgenized females was opposite to that of the males. The present work demonstrated that stimulation of prolactin secretion in androgenized female rats resulted from oestrogen action due to permanent oestrus rather than from impairment of hypothalamo-hypophysial relationships. Indeed, prolactin stimulation was suppressed when the androgenized rats were ovariectomized and restored when they were subsequently implanted with oestradiol in the POA.

EFFECTS OF ANDROGENS AND PROLACTIN ON THE RATE OF PRODUCTION AND COMPOSITION OF SEBUM IN HYPOPHYS-ECTOMIZED FEMALE RATS

1970 ◽  
Vol 48 (3) ◽  
pp. 373-378 ◽  
Author(s):  
T. NIKKARI ◽  
M. VALAVAARA
Keyword(s):  
Production Rate ◽  
Testosterone Propionate ◽  
Skin Surface ◽  
Female Rats ◽  
Sebaceous Glands ◽  
Androgenic Activity ◽  
Surface Lipids ◽  
Skin Surface Lipids ◽  
Relative Potencies ◽  
Stimulation Of

SUMMARY The effect of five androgens on the activity of the sebaceous glands of female rats hypophysectomized at 3–4 weeks of age was studied by determining the rate of production and palmitate: stearate ratio of the skin surface lipids. Both of these values reflected the stimulation of the sebaceous glands by androgens, but the palmitate: stearate ratio appeared to be a more sensitive index of low androgenic activity than the production rate. The response of the sebaceous glands to the androgens tested increased in the order (the relative potencies were calculated from the palmitate: stearate ratios): androstenedione, 17; dehydroepiandrosterone, 33; androstanolone, 48; androstanediol, 91; and testosterone propionate, 100. Prolactin did not enhance the stimulation of the sebaceous glands induced by testosterone propionate.

Sex difference in histamine metabolism in rats

1959 ◽  
Vol 197 (6) ◽  
pp. 1258-1260 ◽  
Author(s):  
K. S. Kim
Keyword(s):  
Sex Difference ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Free Form ◽  
Total Output ◽  
Normal Female ◽  
Histamine Metabolism ◽  
Endogenous Histamine ◽  
Male And Female Rats ◽  
The Difference

The pattern of endogenous histamine excretion in the urine of male and female rats has been studied. The major sex difference is that females put out approximately 25 times more free histamine than males. This difference in free histamine output accounts for the difference in total output. Castration increased free histamine output in males, but ovariectomy or combined ovariectomy and hysterectomy have no effect on output in females. The castration effect appears in 2–5 weeks. One milligram of testosterone propionate when injected subcutaneously suppresses the output of free histamine in castrated rats, but not in normal female rats. There are also sex differences in the handling of exogenous histamine. Castrated and female rats excrete a larger proportion of exogenous histamine in the free form. This indicates that a difference in handling rather than in rate of production may account wholly or partly for the observed sex difference in endogenous histamine output.

Regulation of luteal activity in adult female rats treated neonatally with testosterone propionate

1983 ◽  
Vol 96 (3) ◽  
pp. 417-425 ◽  
Author(s):  
P. van der Schoot ◽  
W. J. de Greef
Keyword(s):  
Plasma Levels ◽  
Testosterone Propionate ◽  
Prolactin Secretion ◽  
Human Chorionic Gonadotrophin ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Normal Female ◽  
Female Rat ◽  
Lower Plasma ◽  
Decidual Tissue

The present study was concerned with the control of luteal activity in female rats which had been treated neonatally with 1·25 mg testosterone propionate (TP). Treatment of such rats in adulthood with 15 i.u. human chorionic gonadotrophin induced ovulation followed by a period of luteal activity. The two daily surges of prolactin secretion, typical for a period of luteal activity in the normal female rat, were not observed in TP-treated females. Instead, higher basal levels of prolactin were observed in TP-treated females than in normal female rats. Furthermore, uterine traumatization at 5 days after ovulation did not result in the formation of decidual tissue. In intact TP-treated females luteal activity, induced and temporarily sustained by an ectopic pituitary transplant, persisted after removal of the pituitary graft. In contrast, in TP-treated females which had been ovariectomized on day 25 of age and had received an ovarian transplant before induction of the luteal phase, luteal activity ended within a week after removal of the ectopic pituitary gland. Females treated with TP which had been ovariectomized on day 25 of life had lower plasma levels of prolactin and higher levels of dopamine in hypophysial stalk plasma than intact TP-treated females when measured at 4 months of age. Treatment of ovariectomized rats with oestradiol-17β increased levels of prolactin in plasma and lowered levels of dopamine in hypophysial stalk plasma. It is concluded that the control of luteal activity in TP-treated females shows 'male' characteristics. However, the presence of the ovaries in such rats leads to decreased hypothalamic release of dopamine and increased plasma levels of prolactin, probably due to increased oestrogen levels. These increased levels of prolactin are sufficient to maintain luteal activity.

LUTEINIZATION OF OVARIAN GRAFTS IN RATS RELATED TO TREATMENT WITH TESTOSTERONE IN THE NEONATAL PERIOD

1969 ◽  
Vol 43 (2) ◽  
pp. 253-NP ◽  
Author(s):  
W. LADOSKY ◽  
J. G. L. NORONHA ◽  
I. F. GAZIRI
Keyword(s):  
Wistar Rats ◽  
Testosterone Propionate ◽  
Neonatal Period ◽  
Central Mechanism ◽  
Female Rats ◽  
Corpora Lutea ◽  
Male Wistar Rats

SUMMARY Male Wistar rats were castrated on the day of birth and divided into two groups; the first was injected with 0·1 mg. testosterone propionate (TP), on the day of castration and the second with 0·5 mg. TP after day 10. When 45 days old, all were grafted with an ovary in the kidney. Animals in the first group showed ovaries with ripening follicles without corpora lutea; those in the second group had corpora lutea at different stages of maturation. Ovaries grafted into female rats spayed on the day of birth developed luteinization even when injected with 0·5 mg. TP after the 10th day of life, but not if the hormone was injected earlier. Since the hypothalamus is sensitive to androgens only before the 10th day of life even in gonadectomized rats, it can be argued that the female pattern of gonadotrophin control does not correspond to the undifferentiated hypothalamus but depends on some active central mechanism. The period during which the hypothalamus is still sensitive to androgens would correspond to the undifferentiated equipotential stage.

Neonatal testosterone potentiates stimulated prolactin secretion in adult oestrogen-primed rats

1986 ◽  
Vol 109 (1) ◽  
pp. 57-60 ◽  
Author(s):  
R. G. Dyer ◽  
S. Mansfield
Keyword(s):  
Testosterone Propionate ◽  
Prolactin Secretion ◽  
Female Rats ◽  
Neonatal Exposure ◽  
Adult Rats ◽  
Blood Samples ◽  
Before And After ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Stimulation Of

ABSTRACT Blood samples were collected from oestrogen-primed gonadectomized adult rats before and after electrical stimulation of the preoptic part of the hypothalamus. Six groups of rats were used for the experiments. These were (a) males castrated on the first day of life, (b) males castrated after puberty, (c) females ovariectomized after puberty and (d), (e) and (f) females given testosterone propionate at birth (1·25, 0·125 and 0·0125 mg/rat respectively). Neonatal exposure of the female rats to testosterone caused a dose-dependent increase in the amounts of prolactin released to levels significantly (P<0·01) higher than those observed in male animals and in untreated females. The results indicate that although neonatal testosterone inhibits oestrogen-stimulated prolactin secretion in adult rats, the neuroendocrine apparatus controlling secretion of the hormone is capable of being activated to greater effect after exposure to androgens at the time of birth. J. Endocr. (1986) 109, 57–60

LORDOSIS BEHAVIOUR IN MALE, FEMALE AND ANDROGENIZED FEMALE RATS

1976 ◽  
Vol 70 (3) ◽  
pp. 409-420 ◽  
Author(s):  
P. SÖDERSTEN
Keyword(s):  
Testosterone Propionate ◽  
Female Rats ◽  
Male Rats ◽  
High Dose ◽  
Normal Female ◽  
Adult Rats ◽  
Oestradiol Benzoate ◽  
Series Of Experiments ◽  
Lordosis Behaviour ◽  
Dose Dependent

SUMMARY Sex differences in the lordosis response of adult rats to ovarian hormones were studied in a series of experiments. Male rats were less sensitive to oestradiol benzoate (OB, a single injection of 10, 100 or 1000 μg/kg or seven daily injections of 2, 10 or 50 μg/kg) than were female rats. Oestradiol benzoate-primed (10 μg/kg) female, but not male, rats showed dose-dependent responses to progesterone (0·4, 2·0 or 10·0 mg/kg). Male rats responded clearly to progesterone (2 mg/rat) only when primed with a high dose of OB (100 μg/rat). Display of the whole pattern of female sexual behaviour was induced in male rats by treatment with 100 μg OB and 2 mg progesterone. Female rats treated with 1 mg testosterone propionate (TP) on day 4 of life, ovariectomized as adults and tested under the same endocrine conditions as the rats described above, retained behavioural OB sensitivity but responded poorly to progesterone. Evidence is presented that ovarian secretions during development significantly modify the response of neonatally TP-treated and normal female rats to OB in adulthood.

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