Further studies on gonadotropin-inhibiting substances excreted in human urine.

M, Ota; Sato, Nobuko; Obara, Kazuo

doi:10.1507/endocrj1954.24.545

Cited by 4 publications

(3 citation statements)

References 7 publications

(8 reference statements)

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“…Such substances were also found in urine by many authors (f.i. Damian, 1972) and in urine and pineal glands by Ota et al (1977). It has also been observed that gonad-inhibiting substances, isolated from urine and most probably originating from the pineal gland, show anti-tumor activity (Dobrovols#aia-Zavadsleaia and Zephiroff,, 1940).…”

Section: Discussionmentioning

confidence: 98%

Effect of melatonin on experimental tumors under different photoperiods and times of administration

Bartsch

1981

J. Neural Transmission

112

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The effects of melatonin on experimental tumors so far described in the literature are contradictory. This may partially be due to negligence of the importance of environmental photoperiodic conditions and to the time of day of administration. In order to test whether the effect of melatonin on day of administration. In order to test whether the effect of melatonin on tumor growth is dependent on the photoperiod and the time of day of administration, the present experiments were carried out. It appears that under long photoperiods melatonin shows opposite effects on fibrosarcoma ascites and Ehrlich solid tumors depending on the time of the day at which the compound was administered. Tumor are stimulated by melatonin injections in the morning and inhibited by late afternoon injections. Experiments under L:D=12:12 and L:D=8:16 do not show such pronounced antagonistic effects. These results support our hypothesis that the effect of melatonin on tumor growth is dependent on the photoperiod and the time of day of administration. Possible mechanisms involved in these effects are discussed.

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Section: Discussionmentioning

confidence: 98%

Effect of melatonin on experimental tumors under different photoperiods and times of administration

Bartsch

1981

J. Neural Transmission

112

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“…In addition, attempts have been made to separate substances in human urine which are able to suppress ovulation induced by pregnant mare serum and human chorionic gonadotrophin (hCG) in mice (Ota, Sato & Obara, 1977). The presence of isoantibodies to hCG and luteinizing hormone (LH) in normal human serum has recently been described (Wass, McCann & Bagshawe, 1978) and these may act as potential inhibitors of hCG/LH activity.…”

Section: Introductionmentioning

confidence: 99%

Substantial Amounts of Gonadotrophin-Like Materials in Sera of Normal Subjects

Pala¹,

Marinelli²,

Gregorio³

et al. 1981

Journal of Endocrinology

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Ultrafiltration of human sera resulted in increased levels of human chorionic gonadotrophin (hCH), LH and FSH measured by radioimmunoassay. The effect was greatly enhanced by chromatography of serum through Sepharose-protein A (which specifically binds immunoglobulin G) followed by ultrafiltration of the unretarded fractions. Serum from a normally menstruating women was treated by ultrafiltration and the retained fraction from 200 mul serum further chromatographed on a Sephadex G-150 Superfine column. The amounts of LH and FSH measured in the eluate by radioimmunoassay were higher by three orders of magnitude than those found in the untreated serum. Comparable amounts of hCG were also found in the eluate by two specific radioimmunoassays, and a value of 45 i.u. hCG was recovered in the eluate by bioassay. Serum from another normally menstruating women was applied to DEAE-cellulose and eluted stepwise using an elution gradient. The ultrafiltrate of one eluted fraction led to separation of a low molecular weight material which was able to neutralize the biological activity of a large dose of hCG. The data support the hypothesis that substantial amounts of gonadotrophins are normally present in serum but that binding to inhibitor(s) prevents their assay in untreated sera.

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“…The stimulation of RNA and protein synthesis in the liver by the administration of androgens (Roy et al, 1974) and also the syntheses of DNA-mediated RNA and protein in the induction of certain enzymes by testosterone (Ota et al, 1977 suggest the possibility of the presence of an androgen receptor in the liver which is considered to be a non-target organ. There is evidence indicating the presence of protein in the liver which has a binding affinity with 5a-dihydrotestosterone (Milin and Roy, 1973) or androstenedione (Gustafsson et al, 1975).…”

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confidence: 99%