EFFECTS OF NEONATALLY INJECTED NON-ESTERIFIED TESTOSTERONE ON REPRODUCTIVE FUNCTIONS IN FEMALE RATS

1971 ◽  
Vol 66 (4) ◽  
pp. 720-726 ◽  
Author(s):  
T. Alklint ◽  
A. Norgren
Keyword(s):  
Exposure Time ◽  
Testosterone Propionate ◽  
Female Rats ◽  
List Type ◽  
Double Dose ◽  
Neonatal Rats ◽  
Duration Of Action ◽  
Old Rats

ABSTRACT The effect of 1.5 mg testosterone (T) given to neonatal rats of various ages was compared with that of 1.5 mg testosterone propionate (Tp) injected into 5 day old rats. Androgenization of the rats was obtained: with Tp in 100 per cent, with T on day 2 in 79 per cent, with T on day 5 in 50 per cent, with T on day 10 in 18 per cent, with a double dose of T on day 5 in 61 per cent, with T on day 5 and 10 in 100 per cent. The results emphasize the importance of the duration of action of the preparation given. The possibility is considered that a minimal exposure time of more than a few hours is required to produce androgenization of 5 day old female rats.

EARLY EFFECTS OF TESTOSTERONE PROPIONATE INJECTED INTO 5 DAY OLD RATS

1965 ◽  
Vol 49 (3) ◽  
pp. 453-465 ◽  
Author(s):  
Dora Jacobsohn ◽  
A. Norgren
Keyword(s):  
Testosterone Propionate ◽  
Mammary Glands ◽  
Compensatory Hypertrophy ◽  
List Type ◽  
Vaginal Opening ◽  
Vaginal Smears ◽  
Duration Of Action ◽  
Old Rats ◽  
Early Effects ◽  
Made In

ABSTRACT The present work deals with problems concerning a) factors influencing gonadal growth in rats during the first two weeks of life and b) the duration of action of 1.5 mg testosterone propionate (testosterone) injected subcutaneously into 5 day old rats (androgenized rats). Five groups of experiments were performed. The results were as follows: Injection of testosterone to 5 day old males reduced the growth of testes from 5 days after injection onwards. Semicastration at 1 day after birth was followed within 14 days by a compensatory hypertrophy of the remaining testis. Androgenization did not prevent a compensatory hypertrophy, but the weight of the remaining testis was reduced as compared with uninjected males. Unilateral ovariectomy at 1 day after birth failed to influence the weight of the remaining ovary recorded after 14 days. Observations on the occurrence of first oestrus and the type of vaginal smears were made in spayed rats receiving ovarian transplants in the anterior eye chamber when 15 days old. Either donors or recipients were androgenized. Testosterone had no effect on the ovaries. Intervals between injection of testosterone and vaginal opening decreased with advancing age both in intact and spayed rats. When testosterone was given to 5 or 18 day old rats, vaginal opening occurred after about 19 and 4 days, respectively. The response of mammary glands of spayed rats with or without androgenization indicated that a) testosterone produced an effect when the rats were about 10 days old and b) testosterone was effective for approximately 15 days.

Interaction between the α2-adrenergic system and nursing in the regulation of growth hormone secretion in the neonatal rat

1993 ◽  
Vol 128 (2) ◽  
pp. 184-191 ◽  
Author(s):  
Bálint Kacsóh ◽  
Judith S Opp (Meyers) ◽  
William R Crowley ◽  
Clark E Grosvenor
Keyword(s):  
Growth Hormone ◽  
Neonatal Rat ◽  
Female Rats ◽  
Adrenergic System ◽  
Neonatal Rats ◽  
Humoral Factors ◽  
Adrenergic Agents ◽  
Gh Secretion ◽  
Old Rats ◽  
Serum Gh

Separation of neonatal rats from their mothers decreases, while a subsequent period of suckling (nursing) increases, serum growth hormone (GH) levels in neonatal rats. Milk-borne (humoral) factors and neural factors inherent in mother-offspring interaction have been implicated in these phenomena. Conflicting reports have demonstrated the α2-adrenergic agonist clonidine to increase and to decrease serum GH levels in 10-day-old rats. The present experiments were aimed at testing whether an interaction between the α2-adrenergic system and the nursing-induced changes in GH secretion could account for the discrepancy. Rat pups were treated with clonidine (150 μg/kg) or the α2-adrenergic antagonist yohimbine (10 mg/kg), and the drug treatment was combined with separation of the mothers and nursing. Yohimbine did not affect serum GH levels in separated two-day-old pups (i.e. basal levels of the hormone), but prevented the nursing-induced increase in serum GH concentration. In two-day-old pups, clonidine had no effect on basal GH levels but, like yohimbine, prevented the increase in serum GH normally associated with nursing. Both yohimbine and clonidine prevented active sucking behavior, i.e. the pups did not search for and/or attach to the nipples of their mothers. Moreover, the pups treated with yohimbine and clonidine were cooler to the touch than the littermate controls. In eight-day-old pups, yohimbine prevented the nursing-induced increase in serum GH and decreased GH levels below the saline-injected, separated control. As in two-day-old pups, clonidine prevented the suckling-induced release of GH and failed to induce GH-release above that of saline-injected, separated pups. By day 10 postpartum. clonidine became capable of stimulating GH release, but only in separated male pups. The effects of CLO and nursing in male pups were not additive: either treatment alone was as effective as the combined treatment. In female rats CLO prevented the increase in serum GH levels in response to nursing. It is concluded that (1) the α2-adrenergic agents yohimbine and clonidine inhibit nursing-induced GH secretion in an indirect (perhaps hypothermia-related) manner not involving the well-established α2-adrenergic-GH releasing hormone pathway; (2) the α2-adrenergic system becomes fully functional in terms of stimulation of GH secretion between days 8 and 10; (3) the GH-releasing effects of the α2-adrenergic system are sexually dimorphic in 10-day-old rats.

HYPOTHALAMIC MONOAMINES AFTER THE NEONATAL ANDROGENIZATION, CASTRATION OR RESERPINE TREATMENT OF THE RAT

1971 ◽  
Vol 66 (2) ◽  
pp. 317-324 ◽  
Author(s):  
M. Hyyppä ◽  
U. K. Rinne
Keyword(s):  
Cerebral Cortex ◽  
Testosterone Propionate ◽  
Hormone Secretion ◽  
Female Rats ◽  
Male Rats ◽  
Green Fluorescence ◽  
Serotonin Content ◽  
Reserpine Treatment ◽  
Monoaminergic System ◽  
Old Rats

ABSTRACT The content of hypothalamic monoamines in the early androgenizated, castrated or reserpinized rats has been studied. Female rats were injected intraperitoneally on the 4th day after birth with either testosterone propionate (650 μg) or reserpine (50 μg), and male rats were either injected with reserpine (50 μg) or castrated. Primary catecholamines were demonstrated histochemically by the formaldehyde fluorescence method in the hypothalami of 30- and 60-day-old rats that had been so treated. Reserpine diminished the intensity of formaldehyde-induced fluorescence at 30 days but had no effect at 60 days. In castrated animals, a slightly increased intensity of yellow-green fluorescence was visible prepuberally in some arcuate cell bodies. Quantitative estimations of noradrenaline and serotonin content in the hypothalamus and cerebral cortex of rats were in agreement with the results obtained in the histochemical studies. Only reserpine had a tendency to reduce the quantity of monoamines in 30-day-old rats, but was ineffective in 60-day-old rats. The results are considered to support the idea that the effect of reserpine on the gonadotrophic hormone secretion might be mediated through hypothalamic monoaminergic system.

THE EFFECTS OF SEX STEROIDS ON THE PROLACTIN CONTENT OF HYPOPHYSES AND SERUM IN RATS

1963 ◽  
Vol 43 (1) ◽  
pp. 137-146 ◽  
Author(s):  
O. L. Wolthuis
Keyword(s):  
Sex Steroids ◽  
Testosterone Propionate ◽  
Mature Female ◽  
Mature Male ◽  
Female Rats ◽  
Male Rats ◽  
List Type ◽  
Oestradiol Benzoate ◽  
Prolactin Content ◽  
Pituitary Prolactin

ABSTRACT Prolactin determinations have been carried out on the hypophyses and serum of rats. It was found that: Hypophyses of intact mature female rats contain almost twice as much prolactin as those of mature female rats spayed two months previously. The pituitary prolactin content in these spayed female rats is virtually identical with that of intact or castrated mature male rats. Treatment of intact mature female rats with oestradiol benzoate (50 μg daily for one week) considerably increases the prolactin content in the hypophyses and serum. Treatment of spayed mature female rats with sex steroids for two weeks shows that: oestradiol benzoate (50 μg daily) increases the prolactin content in the hypophyses and serum; testosterone propionate (2 mg daily) also increases the prolactin content in the hypophyses and serum, although the increases found were smaller than those obtained with the above-mentioned dose of oestradiol; progesterone (5 mg daily) did not significantly alter the pituitary prolactin content, whereas a highly suggestive increase was found in the serum content. From the results it was concluded that: Physiological amounts of androgens do not affect the prolactin function of the hypophysis, whereas physiological amounts of oestrogens do affect it. All three sex steroids investigated increase prolactin production in and secretion from the hypophysis. A negative feedback seems to be absent.

DEVELOPMENT OF FEMALE RATS INJECTED SHORTLY AFTER BIRTH WITH TESTOSTERONE OR »ANABOLIC STEROIDS«

1964 ◽  
Vol 45 (3) ◽  
pp. 402-414 ◽  
Author(s):  
Dora Jacobsohn
Keyword(s):  
Ovarian Function ◽  
Testosterone Propionate ◽  
Anabolic Steroids ◽  
Newborn Infants ◽  
Reproductive Organs ◽  
Female Rats ◽  
Corpora Lutea ◽  
List Type ◽  
Vaginal Smears ◽  
Early Effects

ABSTRACT The present work is concerned with early effects of a single injection of 1.5 mg testosterone propionate into 5 day old female rats (injected rats). Effects of »anabolic steroids« given to rats shortly after birth, generally on the 5th day, were also studied. Untreated littermates served as controls. As early as 5 days after injection (rat's age 10 days) a reduction in ovarian weight was noticeable. At 10 days after injection the ovaries weighed less than those of controls. Vaginal smears showing cornified cells were obtained from injected rats about 5 days prior to controls. At the controls' first oestrous the ovaries of the injected rats weighed approximately 60 per cent of those of the controls. At this time the ovaries of the controls contained large follicles but no corpora lutea. Confirming previous results of other workers, injected rats observed for about 2 months presented constant vaginal oestrous and ovaries without corpora lutea. The ovaries weighed less than half those of the controls. This result was obtained irrespective of whether one ovary had been removed a fortnight previously, or not. Rats given 1.5 mg testosterone propionate at 20 days of age did not show any persistent effects. Records of weight of body, pituitary gland and adrenals were also in agreement with results of other investigators. Results obtained from similar experiments with »anabolic steroids« (19-nor-testosterone, 1-methyl-androst-1-enolone-oenanthate and methan-drostenolone = Durabol, Primobolan and Dianabol, respectively) indicated that, in the doses studied so far, a depression of endocrine activities and/or persistent defects in the development of female accessory reproductive organs and ovarian function may occur in rats after an injection given within 24 hours after birth or at 5 days of age. The importance of further investigations with regard to the clinical use of »anabolic steroids«, particularly in newborn infants, is discussed.

Modification of Pineal Ultrastructure by Exogenous Hormones

1967 ◽  
Vol 25 ◽  
pp. 170-171
Author(s):  
R. A. Turner ◽  
A. E. Rodin ◽  
D. K. Roberts
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
List Type ◽  
Type Number ◽  
Pregnant Rats ◽  
Gonadal Atrophy ◽  
Pineal Ultrastructure

There have been many reports which establish a relationship between the pineal and sexual structures, including gonadal hypertrophy after pinealectomy, and gonadal atrophy after injection of pineal homogenates or of melatonin. In order to further delineate this relationship the pineals from 5 groups of female rats were studied by electron microscopy:ControlsPregnant ratsAfter 4 weekly injections of 0.1 mg. estradiol benzoate.After 8 daily injections of 150 mcgm. melatonin (pineal hormone).After 8 daily injections of 3 mg. serotonin (melatonin precursor).No ultrastructural differences were evident between the control, and the pregnancy and melatonin groups. However, the estradiol injected animals exhibited a marked increase in the amount and size of rough endoplasmic reticulum within the pineal cells.

INTERACTIONS OF OESTRONE AND TESTOSTERONE ON MAMMARY GLANDS OF MALE RABBITS

1961 ◽  
Vol 36 (1) ◽  
pp. 141-156 ◽  
Author(s):  
B. Bengtsson ◽  
A. Norgren
Keyword(s):  
Mammary Gland ◽  
Testosterone Propionate ◽  
Mammary Glands ◽  
List Type ◽  
Stunted Growth ◽  
Abnormal Growth ◽  
Growth Reaction ◽  
Extensive Growth ◽  
Higher Doses

ABSTRACT The effect of testosterone and oestrone on the mammary glands of castrated male rabbits was studied. Testosterone propionate was used in daily doses from 0.5 to 80 mg. The doses of oestrone ranged from 0.05 to 25 μg per day. Mammary glands were examined after 14, 28 or 56 days of injections. 1) Testosterone in doses below 20 mg failed to affect the mammary glands. With 40 or 80 mg a distinct, though abnormal growth reaction was consistently obtained. 2) Oestrone in doses lower than 0.5 μg did not stimulate mammary growth. With 0.5 μg and higher doses extensive growth of the mammary glands occurred. Stunted growth and secretion were found in the mammary glands of rabbits injected with 12.5 or 25 μg oestrone. 3) Testosterone in doses of 1 or 5 to 10 mg depressed or abolished the response of the mammary glands to 0.5 μg oestrone. When testosterone, in doses ineffective when given alone, was added to at least 3.125 μg oestrone, the mammary glands developed alveoli. The abnormalities produced by the highest doses of oestrone studied were exaggerated by the addition of testosterone. 4) The observations indicate a complicated interplay between the actions of testosterone and oestrone on the mammary gland of the rabbit. The interactions between testosterone and oestrone are presumably different from those observed between progesterone and oestrone.

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS:

1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson
Keyword(s):  
Ascorbic Acid ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Female Rat ◽  
Feedback Effects ◽  
Male And Female ◽  
Prostate Weight ◽  
Male And Female Rats ◽  
Males And Females ◽  
Normal Males

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.

BEFUNDE AM GENITALTRAKTUS DER RATTE NACH CORTICOTROPIN-INJECTION UND IHRE DEUTUNG UNTER BERÜCKSICHTIGUNG DES ZELLBILDES DER ADENOHYPOPHYSE

1959 ◽  
Vol XXXII (II) ◽  
pp. 167-176 ◽  
Author(s):  
Walter Schätzle
Keyword(s):  
Adult Female ◽  
Single Injection ◽  
Anterior Lobe ◽  
Vaginal Epithelium ◽  
Female Rats ◽  
Normal Adult ◽  
List Type

ABSTRACT In normal adult female rats a single injection of 5 IU corticotrophin was followed by a retention of glucoproteid material in the anterior lobe of the hypophysis and by impairment of the luteinization. In spayed adult female rats the same corticotrophin administration caused stratification and mucification of the vaginal epithelium.

Effects of trenbolone acetate and testosterone on growth and on plasma concentrations of corticosterone and ACTH in rats

1990 ◽  
Vol 126 (3) ◽  
pp. 461-466 ◽  
Author(s):  
M. N. Sillence ◽  
R. G. Rodway
Keyword(s):  
Weight Gain ◽  
Growth Response ◽  
Plasma Concentrations ◽  
Female Rats ◽  
Male Rats ◽  
Adrenal Weight ◽  
Trenbolone Acetate ◽  
Male And Female Rats ◽  
Age Related ◽  
Old Rats

ABSTRACT The effects of trenbolone acetate (TBA) on growth and on plasma concentrations of corticosterone were examined in male and female rats. At 5 weeks of age, rats were injected with TBA (0·8 mg/kg) dissolved in peanut oil, or with oil alone, daily for 10 days. In female rats, TBA caused an increase in weight gain (20–38%), a reduction in adrenal weight (19%) and a reduction in plasma concentrations of corticosterone (55%). In contrast, TBA-treated male rats showed no significant increase in weight gain, no significant change in adrenal weight and no reduction in plasma concentrations of corticosterone. The mechanism by which adrenal activity was suppressed in TBA-treated female rats was examined and the response compared with that to testosterone. Female rats (8 weeks old) were injected daily either with oil vehicle, TBA (0·8 mg/kg) or testosterone propionate (0·8 mg/kg). Testosterone increased weight gain (24%), but the growth response to TBA treatment was significantly greater (97%). A reduction in plasma concentrations of corticosterone (45%) was again observed in response to TBA. However, testosterone increased plasma concentrations of corticosterone (52%) above those of control values. Neither androgen affected plasma concentrations of ACTH. Finally, the effects of TBA were examined in 6-week-old female rats, to characterize further the apparent age-related increase in responsiveness. The growth response of 6-week-old rats (60–74%) was intermediate between that seen in 5- and 8-week-old animals. It is concluded that part of the anabolic activity of TBA may be related to a reduction in circulating concentrations of corticosterone. The effect of TBA on corticosterone concentrations differs from that of the natural androgen, testosterone, and does not appear to be mediated by a reduction in plasma concentrations of ACTH. Journal of Endocrinology (1990) 126, 461–466

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