Folia Endocrinologica Japonica

International Unit and Standards of Gonadotropins

Ryosuke NAKANO

1972 Volume 47 Issue 10 Pages 624-630,619
Published: January 20, 1972
Released on J-STAGE: September 24, 2012

DOIhttps://doi.org/10.1507/endocrine1927.47.10_624

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The important role played by the World Health Organization (WHO) in the establishment and distribution of international standards and international reference preparation have long been recognized. The availability of standards and reference preparations ensures the uniformity of the potency of preparations manufactured and used throughout the world and facilitates and unifies research throughout the world.
The definition of standards distributed by the WHO is as follows : International standard is a preparation to which an international unit is assigned on the basis of an extensive international collaborative study. The standard is intended for use in the estimation of potency of a test sample by direct comparison of the two materials in a biological test system. A collaborative study is usually made to ensure that the proposed preparation would be suitable as an international standard in the hands of different workers and, if appropriate, by a number of different assay methods. International reference preparation may serve a function similar to that of international standard but is established either without full international study which proceeds the establishment of an international standard, or when a collaborative study has shown that the preparation is, for some reason, not entirely suitable to serve as an international standard.
A brief review of the historical development of standards for gonadotropins was presented

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Influence of Electrical Activation in the Preoptic Area upon Ovarian Function

Kazuchika YOSHIDA

1972 Volume 47 Issue 10 Pages 631-647,620
Published: January 20, 1972
Released on J-STAGE: September 24, 2012

DOIhttps://doi.org/10.1507/endocrine1927.47.10_631

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In rabbits which is reflex ovulatory, the function of the lateral preoptic area was not known like one of the important function for regulate gonadal hormone and ovulation. Therefore the purpose was to investigate the activity in the lateral preoptic area (LPO), medial preoptic area (MPO), arcuate nucleus (ARC) and medial reticular formation (m-RF) after the copulation and the effect of the lateral preoptic stimulation upon the activity in the ARC and ovarian function. The electrodes to record multiple unit activity (MUA) and to stimulate were chronically implanted. In corporation of acetate-1-¹⁴C into ovarian progestin and estrogen was measured. 1) In the cases which induced ovulation after copulation, the level of integrated MUA in the LPO and m-RF immediately increased after copulation. On the other hand, the level of integrated MUA in the basal part of the MPO and superior part of the ARC slightly increased after copulation, but medial part of the MPO and basal part of ARC slightly decreased. 2) The level of integrated MUA similarly increased after cervical stimulation or female pseudo-copulation (male presents mounting behavior but female not lordosis) and in these cases ovulation was not induced. 3) In the ovariectomized female rabbit, progesterone injection primed with estradiol was observed possible for permission and after progesterone injection the level of integrated MUA of the LPO, medial part of MPO and superior part of the ARC increased slightly but basal part of MPO and superior part of ARC was decreased almost 3 or 5 hours after the injection. 4) In the ovariectomized rabbit the level of integrated MUA of the LPO increased remarkably but the MPO and ARC slightly increased. 5) After the administration of high doses of estradiol, progesterone, PMS and HCG the integrated MUA in these area was not recorded any change. 6) The electrical stimulation of the LPO provoked ovulation in 6 animals within 16 and was ob-served a large hemorrhagic follicle in 5 animals following increase in the biosynthesis of ovarian progestin, while the stimulation of the MPO was observed no change in the ovary. 7) In the cases that induced ovulation by electrical stimulation of the LPO, the integrated MUA of the ARC (basal part) was presented several changes like showing depression and rapidly arise about 1 hour and again inhibition till about 6 hours after the stimulation, in negative cases of ovulation by stimulation of the MPO, the level of integrated MUA was not recorded remarkable change.
From above mentioned results, in the rabbit the LPO take part of important neural regulating mechanism of gonadotropin secretion through the basal hypothalamo-pituitary axis. And it might be suggested that the LPO was a some moderate station to switch from sexual behavior to endocrine efferent neuron.

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Competitive Protein-Binding Analysis Using Rat Plasma as a Source of C.B.G.

Atsuo KAWAI, Toshiko ISHII, Nobusada KUZUYA

1972 Volume 47 Issue 10 Pages 648-653,622
Published: January 20, 1972
Released on J-STAGE: September 24, 2012

DOIhttps://doi.org/10.1507/endocrine1927.47.10_648

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Since the competitive protein-binding analysis (CPBA) was first introduced as a technique for the measurement of cortisol by Murphy et al, it has been widely applied for assay of various steroid hormones. In most cases, CBG in human plasma has been employed as the assay protein. Few reports have been made on CPBA using steroid-binding protein of other spesis than human being, although it was established that there existed the CBG in plasma of animals of various species.
The present work is concerned with investigating the specificity and sensitivity of the CPBA using rat plasma CBG. The specificity of this assay system was evaluated by degree of competition of various steroids examined with tritiated corticosterone for binding sites in a 500 fold diluted adrenalectomized rat plasma. Corticosterone displaced bound 3H-corticosterone most effectively. Cortisol and 11-deoxycorticosterone behaved as the second and third potent competitor, respectively. Cortisone, aldosterone and estradiol did not compete with ³H-corticosterone.
To test suitability of CBG from rats undergone various treatments, the slopes of replacement curves were compared. Bilateral adrenalectomy increased its affinity and avidity to corticosterone and pretreatment with dexamethasone depressed them. CBG in a female rat plasma exhibited apparently a higher affinity and avidity to the steroid than that of male rat plasma. The most suitable standard curve was obtained when either a 500 fold diluted female or a 700 fold diluted male adrenalectomized rat plasma was used. The measurable range of corticosterone in this case was from 0.5 to 10 ng. Using such plasma it was possible to determine the quantity of corticosterone in as little as 0.05 ml of adrenal venous plasma of hypophysectomized rats.
CPBA using rat CBG appears to be a promising method for applying to the bioassay of ACTH as well as for analyzing the dinamics of adrenal cortical secretion.

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The Mode of TRH-Induced Secretion of Biologically Active TSH Observed in Mice

Yoshimasa SHISHIBA, Shizuko YOSHIMURA, Taeko SHIMIZU, Kazuo SHIZUME

1972 Volume 47 Issue 10 Pages 654-657
Published: January 20, 1972
Released on J-STAGE: September 24, 2012

DOIhttps://doi.org/10.1507/endocrine1927.47.10_654

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In an attempt to analyze the mode of TRH-induced secretion of biologically active TSH in vivo, the release of radioactive iodine from the prelabelled thyroid gland was estimated in mice pretreated as described by Bowers and injected with synthetic TRH. The time interval between intravenous injection of TRH and anti-TSH antibody serum capable of neutralizing the released TSH allowed an estimate of the fraction of TSH released during that period. When anti-bovine TSH antibody serum of the rabbit was injected into the assay mice prior to the injection of 40 ng of TRH, no increase in the radioactive iodine release was observed as a result of complete neutralization of discharged TSH. When the same amount of antibody was injected 2, 5, 10 or 20 min. after intravenous injection of TRH, 3, 9, 47 or 78% of the unneutralized response was obtained respectively. A discernible response was obtained when the anti-TSH serum was injected 5 min or more after TRH. On the other hand, when the same amount of anti-TSH serum was injected 2 min prior to or 2, 5, 10 or 20 min after the injection of 0.4 mU of bovine TSH capable of eliciting the almost identical response to 40 ng TRH, 0, 15, 30, 43 or 60% of the unneutralized response was obtained respectively. Here, a discernible response was obtained when anti-TSH serum was injected 2 min, or more after TSH. Thus, the time required for TRH to release substantial amount of TSH would be estimated to be 3 min. or less. The almost identical effect of anti-TSH serum injected 10 or 20 min after TRH or TSH would indicate that the bulk of TSH was discharged by TRH within 10 min. or less.

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[title in Japanese]

1972 Volume 47 Issue 10 Pages 658-697
Published: January 20, 1972
Released on J-STAGE: September 24, 2012

DOIhttps://doi.org/10.1507/endocrine1927.47.10_658

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