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SUMMARY
Urinary gonadotrophins from amenorrhoeic patients were assayed. The results provide preliminary evidence that FSH and ICSH exist as separate entities in human urine. Cortisone treatment appeared to cause a rise in the excretion of FSH relative to ICSH. The reverse effect was caused by treatment with 0·5 mg of stilboestrol daily. Supplementary experiments suggested that prolactin and oestrogen had not interfered in the assays.
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1. An assay method for urinary FSH depending on an increase of ovarian weight in mice treated with HCG has been examined experimentally.
2. Synergism was not observed when mixtures were assayed by this method. However, when 'total gonadotrophic activity' was estimated by the weight increase of the mouse uterus there appeared to be some evidence of synergism.
3. The administration of prolactin in total dosages up to 10 i.u./mouse did not interfere with the assay.
4. The addition of oestrogens sometimes affected the assay results and frequently caused a departure from parallelism.
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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.
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The gonadotrophic fraction, GA, from the urine of various human subjects, when tested biologically, showed a wide range of potency. Potency was high in cases when high gonadotrophin excretion was likely; it was depressed by oestrogens.
It is suggested that GA is a protein vehicle, loaded with variable amounts of gonadotrophic material and that its potency may reflect the concentration of gonadotrophin in the body.
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Immature mice were induced to ovulate by a single injection of pregnant mare serum gonadotrophin (PMS). Additional treatment with 5-hydroxytryptamine (5-HT) during the final 24 hr. of the experiment caused significant alteration in the dose-response relationship for PMS, the ovulatory response to low doses of PMS being increased and that to high doses reduced. Both lysergic acid diethylamide and methysergide caused a consistent and significant reduction in the incidence of ovulation induced under the same test conditions.
Neither 5-HT nor its antagonists influenced spontaneous ovulation in adult mice of a different strain under the conditions tested. Therefore, if 5-HT is involved at some stage in the processes leading up to ovulation when this is induced in immature mice, either it does not have the same importance or its effect is less easily modified under the physiological conditions of spontaneous ovulation in mice of the strain used.
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Ovulation was induced in immature mice by pregnant mare serum gonadotrophin. Reserpine in doses of 6–9 μg. prevented ovulation in these animals. Methoserpidine (up to 333 μg.) did not reduce the incidence of ovulation. A single dose of 2 mg. α-methyldopa was without effect but several doses at intervals inhibited ovulation.
Groups of mice treated with gonadotrophin and reserpine were pretreated with other drugs. α-Methyldopa decreased the sedative effect of reserpine but not its inhibitory effect on ovulation. Dopa antagonized both effects of reserpine.
5-Hydroxytryptamine creatinine sulphate in doses of 100 or 200 μg. injected s.c. 16 or 17 hr. before the mice were killed consistently increased the percentage ovulating in response to gonadotrophin. A significant increase was also obtained when 5-hydroxytryptophan was injected into mice pretreated with iproniazid.
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A dithiocarbamoylhydrazine (ICI 33828) was injected s.c. into intact rats and mice. It usually caused a reduction in weight of the uterus or of the accessory organs in the male, but less commonly of the gonads. As little as 0·5 mg. daily for 4 days caused significant effects in adult female rats, while half this dose on alternate days retarded maturation in male rats.
ICI 33828 was injected with exogenous gonadotrophin in three systems of assay and in some cases it modified the response to the gonadotrophin. This may not be due to a specific effect at the gonadal level but either to suppression of endogenous gonadotrophins in the test animals or to the effect of ICI 33828 on their general condition.
Pituitary glands from male rats treated with ICI 33828 were assayed for follicle stimulating hormone (FSH) and found to contain significantly less than glands from control rats. This suggests that ICI 33828 acts by reducing the formation of pituitary gonadotrophin.
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SUMMARY
Urinary gonadotrophins from post-menopausal patients were tested by two methods of bioassay.
Measured by the response of the mouse uterus, the daily excretion of total gonadotrophin in the less severely disabled patients ranged from 10 to 200 mg. equivalents of HMG 20A. Patients with active rheumatoid arthritis showed similar levels but some patients with severe disability due to anorexia, reticulosis or anaemia excreted very little gonadotrophin.
The gonadotrophins were also measured in terms of follicle-stimulating hormone (FSH) using the ovarian response in mice treated with excess human chorionic gonadotrophin. It was found that they differed strikingly from HMG 20 A in being relatively more potent in the assay for FSH. This suggests that they contained relatively more FSH.
The day-to-day fluctuation in the excretion of total gonadotrophin was compared with the differences between duplicate estimations. There were considerable quantitative fluctuations which could not be explained by the experimental errors. There was little evidence of major fluctuation in the quality of the gonadotrophins when this was assessed in a similar way.
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SUMMARY
Urinary gonadotrophins were assayed against HMG 20 A during the menstrual cycle in four subjects by methods believed to measure follicle stimulating hormone (FSH) and total gonadotrophin respectively. The gonadotrophins showed qualitative fluctuation. Three subjects showed maximum levels of total gonadotrophin near the middle of the cycle, and three showed a notably different pattern of excretion of FSH with high values in the first part of the cycle.
Gonadotrophins from patients with secondary amenorrhoea showed no qualitative fluctuation, but treatment with stilboestrol apparently caused a rise in excretion of interstitial cell stimulating hormone in three out of nine patients.
The results of ninety-eight assays are recorded with fiducial limits and are discussed with reference to the specificity of the methods and the importance of inter-assay errors.
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SUMMARY
Urinary gonadotrophins were assayed in terms of the reference substance HMG20A by methods believed to measure follicle stimulating hormone (FSH) directly and interstitial cell stimulating hormone (ICSH) indirectly.
In normal girls aged 10–11 and 14–15 years urinary FSH was equivalent to 26 and 14 mg HMG20A/1. Gonadotrophin from the older girls was qualitatively similar to HMG20A, but that from the younger girls contained relatively little ICSH. Relative deficiency of ICSH also occurred in some older girls with delayed puberty. Young girls with precocious isosexual development resembled older girls of the 14- to 15-year group by excreting gonadotrophins qualitatively like HMG20A but in smaller amounts.
In normal boys the maximum urinary FSH was only 8·8 mg/l., p: and there was no evidence of relatively low concentrations of ICSH before normal pubertynor when it was abnormally delayed.
The physiological and statistical significance of the demonstrated qualitative differences in urinary gonadotrophins is discussed.