scholarly journals MODIFICATION OF THE RAT UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN BY OESTROGEN

Reproduction ◽  
1973 ◽  
Vol 34 (1) ◽  
pp. 175-177
Author(s):  
L. J. HIPKIN
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Uterine Weight

AUGMENTATION BY CHLORMADINONE OF THE UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN IN INTACT IMMATURE RATS

1965 ◽  
Vol 33 (3) ◽  
pp. 447-454
Author(s):  
M. J. K. HARPER
Keyword(s):  
Single Injection ◽  
Direct Action ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Female Rats ◽  
Uterine Weight ◽  
Control Value ◽  
Orally Active ◽  
Stimulation Of

SUMMARY Administration of chlormadinone, an orally active progestational agent without significant oestrogenic activity, to intact immature female rats did not affect either ovarian or uterine weight significantly compared with controls. A single injection of human chorionic gonadotrophin (HCG) caused a 73 % increase in uterine weight in 24 hr. over the control value. This dose significantly increased ovarian weight and although it caused some stimulation of follicular development, ovulation during this time did not occur. When animals were treated with chlormadinone for 8 days, and received HCG on the 8th day, uterine weight was 170% greater than in the controls and 56% greater than with HCG alone. The uterine weight produced was similar to that found in animals treated with mestranol, a potent oestrogen, and HCG. In ovariectomized animals HCG did not affect uterine weight, while the small increase produced by chlormadinone was unaltered when HCG also was given. Mechanisms are discussed by which this augmentation of the uterine response to HCG might be produced. It seems most likely that chlormadinone administration causes storage of endogenous gonadotrophin in the pituitary, and that the exogenous gonadotrophin acts as the 'trigger' for the release of stored hormone, probably by a direct action on the hypothalamus.

EFFECT OF FREEZING AND THAWING AND OF DILUENT ON THE POTENCY OF HUMAN CHORIONIC GONADOTROPHIN IN THREE METHODS OF BIOASSAY

1969 ◽  
Vol 61 (1) ◽  
pp. 89-95
Author(s):  
Rudi Borth ◽  
Annette Menzi
Keyword(s):  
Ascorbic Acid ◽  
Biological Activity ◽  
Bovine Serum Albumin ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Prolonged Storage ◽  
Distilled Water ◽  
Uterine Weight ◽  
Freezing And Thawing ◽  
Repeated Freezing

ABSTRACT In a study designed as a factorial experiment, the biological activity of standard solutions of human chorionic gonadotrophin in distilled water (A), saline (B), 1 % bovine serum albumin (C), 0.5 % gelatin (D), and borate buffer of pH 9 (E) was investigated under four different conditions of freezing and thawing, using the following three methods of bioassay: ovarian ascorbic acid depletion in rats (OAAD), uterine weight in mice (UW), and ovarian hyperaemia in rats (OH). Repeated freezing and thawing and prolonged storage at -15°C did not affect the potency in any test. In the OAAD test, the potency was increased 4–5fold by D, and 2–3fold by C. In the OH test, E augmented the potency 2–3fold. These findings are of interest in the practice of bioassay, in studying mechanisms of response, and regarding administration for therapeutic purposes. Diluents which possess augmenting properties could be used to improve the sensitivity of a bioassay if standard and unknowns showed the same degree of augmentation.

AUGMENTATION OF THE RAT UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN BY VARIOUS STEROIDS

1974 ◽  
Vol 75 (1) ◽  
pp. 141-147 ◽  
Author(s):  
L. J. Hipkin
Keyword(s):  
Dose Level ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Uterine Weight ◽  
Ovarian Weight ◽  
Gonadotrophin Secretion

ABSTRACT Dehydroepiandrosterone (DHA) augments the activity of human chorionic gonadotrophin (HCG) in the rat by increasing endogenous pituitary gonadotrophin secretion. The following experiments were undertaken to investigate the mechanism underlying this effect. Androstenedione (40 μg), dihydrotestosterone (200 μg) and testosterone (200 μg) augmented the rat uterine weight response to 0.5 IU of HCG. At these doses, the steroids did not affect basal uterine weight although this was increased when 1 mg of a steroid was injected. Androsterone (1 mg), 17α-hydroxypregnenolone (1 mg) and progesterone (200 μg) neither augmented HCG activity nor increased basal uterine weight. Ovarian weight differences were not significant in any of the experiments. Androstenedione, DHA, dihydrotestosterone and testosterone (200 μg dose level) did not significantly affect the uterine weight of castrated animals, and responses to 0.04 μg of oestradiol were not potentiated. The results with androstenedione, dihydrotestosterone and testosterone are identical to those obtained with DHA and suggest that these steroids may also increase pituitary gonadotrophin secretion.

THE EFFECT OF THE URINARY GONADOTROPHIN INHIBITOR ON THE RAT UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN

1970 ◽  
Vol 64 (3) ◽  
pp. 421-430
Author(s):  
L. J. Hipkin
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Hormone Release ◽  
Uterine Weight ◽  
Control Groups ◽  
Mouse Uterus ◽  
Final Body Weight ◽  
Gonadotrophin Secretion ◽  
Small Doses ◽  
The Difference

ABSTRACT A urinary extract (GIM), which previously had been shown to inhibit small doses of human chorionic gonadotrophin (HCG) in the mouse uterus assay, was tested in the rat. In this species, GIM caused an increase in the basal uterine weight and potentiated the response to 0.1 IU HCG. Similar results, and in addition augmentation of the activity of 0.2 IU HCG, were obtained in rats injected with carbon tetrachloride or starved. GIM inhibited the activity of 0.8 IU and 1.6 IU HCG. This was thought to result from the difference in mean final body weight between the GIM and the control groups. The results support the hypothesis that GIM causes a non-specific stress reaction. In rats the effect of this is to increase endogenous gonadotrophin secretion. This contrasts with the results previously reported for mice, which suggest that stress suppresses endogenous follicle-stimulating hormone release.

A COMPARISON OF TWO GONADOTROPHIC EXTRACTS, PMS AND HCG, WITH A CRITICAL EXAMINATION OF ASSAY PROCEDURE

1961 ◽  
Vol 21 (4) ◽  
pp. 459-467 ◽  
Author(s):  
R. B. DONNELLY ◽  
G. M. STONE
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Critical Examination ◽  
Uterine Weight ◽  
Assay Procedure ◽  
Wide Range ◽  
Selection Of

SUMMARY The method of assay for gonadotrophin developed by Claringbold & Lamond (1957) has been found satisfactory and suitable for a wide range of management conditions and strains of mice. It has been confirmed that this method gives similar slopes for human chorionic gonadotrophin and pregnant mares' serum and it has been found, in addition, that these slopes do not differ from strain to strain. An explanation is offered of the contrary results of Brown, Cunningham & Finegan (1959) and some comments are made on the design and analysis of assays, particularly the selection of dose ranges. It is considered that the uterine weight assay offers no evidence for the existence of two separate gonadotrophic principles.

THE ASSAY OF GONADOTROPHIN FROM URINE OF NON-PREGNANT HUMAN SUBJECTS

1955 ◽  
Vol 13 (1) ◽  
pp. 59-64 ◽  
Author(s):  
P. S. BROWN
Keyword(s):  
Human Subjects ◽  
Follicle Stimulating Hormone ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Uterine Weight ◽  
Ovarian Weight ◽  
Stimulating Hormone

SUMMARY Two convenient bioassays of urinary gonadotrophins, using immature mice, are described. The first is based upon the initial doubling of uterine weight. The second, using the ovarian weight response, attempts to increase specificity to follicle stimulating hormone by priming with human chorionic gonadotrophin. The usefulness of both methods is discussed, and the influence of non-specific impurities during the assay of urinary extracts is stressed.

SOME FACTORS AFFECTING THE RESPONSE OF THE IMMATURE MOUSE TO PREGNANT MARE SERUM GONADOTROPHIN AND HUMAN CHORIONIC GONADOTROPHIN

1966 ◽  
Vol 34 (1) ◽  
pp. 41-50 ◽  
Author(s):  
D. R. LANG ◽  
D. R. LAMOND
Keyword(s):  
Dose Response ◽  
Time Of Day ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Uterine Weight ◽  
Restricted Diet ◽  
Factors Affecting ◽  
Immature Mouse ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY Deprivation of food for 24–48 hr. before the injection of gonadotrophin into mice reduced mean uterine weights and the slopes of the dose-response lines; the effect was greater with human chorionic gonadotrophin (HCG) than with pregnant mare serum gonadotrophin. Age and time of weaning relative to the injection of gonadotrophin, and the number of experimental mice per cage, also affected the uterine weight response. Age and weight influenced the number of ovulations after injections of HCG. Fasting for 48 hr. before the priming injection reduced numbers of ovulations as compared with a restricted diet or fasting for 48 hr. after priming. The time of day of the priming and ovulatory injections influenced the number of ovulations, injections in the afternoon resulting in more ova than injections in the morning.

THE EFFECT OF CORTICOTROPHIN ON THE RAT UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN

1971 ◽  
Vol 67 (3) ◽  
pp. 463-469 ◽  
Author(s):  
L. J. Hipkin
Keyword(s):  
Carbon Tetrachloride ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Daily Injection ◽  
Uterine Weight ◽  
Rat Uterus ◽  
Mouse Uterus ◽  
Urine Extract

ABSTRACT The activity of human chorionic gonadotrophin (HCG) in the mouse uterus assay is augmented by the daily injection of corticotrophin (ACTH). This phenomenon has been further investigated in the rat. Synthetic ACTH (75μg) and dehydroepiandrosterone (1.0 mg) augmented responses to 0.1 IU, 0.2 IU and 0.4 IU HCG in the rat uterus assay. The basal uterine weight was also elevated by the treatment. This effect could not be demonstrated in castrated or hypophysectomised animals, and in the latter the response to HCG was not augmented. Cortisone and corticosterone did not affect HCG assay. Cortisone administration did not suppress the augmenting effect of either carbon tetrachloride or urine extract administration on HCG activity. Mean uterine weights from bilaterally adrenalectomised rats were significantly higher than those from intact or sham operated animals. The results are discussed with reference to the augmentation of HCG activity produced by non-specific stressful procedures.

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