Luteinizing hormone-releasing factor: Partial purification

1965 ◽  
Vol 208 (6) ◽  
pp. 1286-1290 ◽  
Author(s):  
M. B. Nikitovitch-Winer ◽  
A. H. Pribble ◽  
A. D. Winer
Keyword(s):  
Luteinizing Hormone ◽  
Small Volume ◽  
Ammonium Acetate ◽  
Solvent System ◽  
The Other ◽  
Partial Purification ◽  
Heat Stable ◽  
Small Polypeptide ◽  
Pass Through ◽  
Acidic Peptides

A method has been devised for the partial purification of luteinizing hormone-releasing factor (LHRF) from extracts of ovine median-eminence tissue. Acid extracts are boiled for 20 min, dialyzed against water for 12 hr, and the dialysate lyophilized. The lyophilized residue is dissolved in a small volume of 5 x 10–3 m ammonium acetate, pH 4.6, and chromatographed on carboxymethylcellulose with an ammonium acetate gradient to 1.0 m, pH 4.6. Several acidic peptides pass through the column rapidly; a peptide with LHRF activity appears in the effluent at about 0.4 m ammonium acetate. The ability of various fractions to induce ovulation on intrapituitary infusion into "atropine-pentobarbital-blocked" proestrous rats was used as the biological test for the release of LH. It was found that, following the infusion of the LHRF-containing fraction, 42 of 54 animals ovulated, while no ovulation was observed in 64 animals treated with any of the other fractions. The LHRF material is probably a small polypeptide which is dialyzable, heat stable, has little absorbancy at either 260 or 280 mµ, and does not give a positive reaction with ninhydrin after paper chromatography in the solvent system used. Evidence is presented that the partially purified LHRF is devoid of LH contamination.

EFFECTS OF CASTRATION, AND TESTOSTERONE IN VITRO, ON THE HYPOTHALAMIC SYNTHESIS OF DIFFERENT PEPTIDE FRACTIONS

1975 ◽  
Vol 64 (1) ◽  
pp. 155-161 ◽  
Author(s):  
J. A. MOGUILEVSKY ◽  
M. A. ENERO ◽  
B. SZWARCFARB ◽  
D. DOSORETZ
Keyword(s):  
Luteinizing Hormone ◽  
Incubation Medium ◽  
Ammonium Acetate ◽  
Follicle Stimulating Hormone ◽  
The Other ◽  
Ovariectomized Rats ◽  
Small Peptides ◽  
Other Hand ◽  
Peptide Fractions

SUMMARY The incorporation of [3H]tyrosine ([3H]tyr) into different hypothalamic peptide fractions isolated from normal and castrated rats on a Sephadex G-25 column has been studied in vitro. Luteinizing hormone releasing factor (LH-RF) activity was determined in the different fractions by measuring their ability to elicit release of radioimmunoassayable luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in ovariectomized rats treated with oestrogen and progesterone. For further purification, the fraction with LH-RF activity was applied to a CM-Sephadex G-25 column eluted with a gradient of ammonium acetate. The large radioactive peptides emerged from the Sephadex G-25 column in fraction S-1, while the small peptides with LH-RF activity were eluted in fraction S-2. Gonadectomy significantly increased the incorporation of [3H]tyr into the peptides of fractions S-2. Only in the purified fraction with LH-RF activity was the radioactivity incorporated higher in gonadectomized than in normal rats. The enhanced incorporation in fraction CM-3 observed after castration implies an increase in the hypothalamic synthesis of peptides with LH-RF activity. The addition of testosterone (2 μg/ml) to the incubation medium of hypothalamus from gonadectomized rats, corrected these modifications. Gonadectomy decreased the incorporation of tyrosine into the large peptides, and incubation with testosterone corrected this change. The modifications in the incorporation of [3H]tyr into the large and small peptides produced by castration appear to indicate that gonadectomy, as well as stimulating the production of LH-RF, enhances the synthesis of other hypothalamic peptides while inhibiting the synthesis of proteins. On the other hand an increase in the breakdown of large peptides into small peptides cannot be excluded.

scholarly journals Milk Protein Fragments Induce the Biosynthesis of Macedocin, the Lantibiotic Produced by Streptococcus macedonicus ACA-DC 198

2009 ◽  
Vol 76 (4) ◽  
pp. 1143-1151 ◽  
Author(s):  
Marina Georgalaki ◽  
Marina Papadelli ◽  
Elina Chassioti ◽  
Rania Anastasiou ◽  
Anastassios Aktypis ◽  
...  
Keyword(s):  
Milk Protein ◽  
Mass Spectrometric ◽  
Partial Purification ◽  
Protein Fragments ◽  
Reverse Transcription Pcr ◽  
Heat Stable ◽  
Heat Stable Protein ◽  
Tandem Mass Spectrometric ◽  
Protein Components ◽  
First Time

ABSTRACT The aim of the present work was to study the mode of the induction of the biosynthesis of macedocin, the lantibiotic produced by Streptococcus macedonicus ACA-DC 198. Macedocin was produced when the strain was grown in milk but not in MRS or M17 broth. No autoinduction mechanism was observed. Production did not depend on the presence of lactose or galactose in the culture medium or on a coculture of the producer strain with macedocin-sensitive or macedocin-resistant strains. Induction seemed to depend on the presence of one or more heat-stable protein components produced when S. macedonicus ACA-DC 198 was grown in milk. The partial purification of the induction factor was performed by a combination of chromatography methods, and its activity was confirmed by a reverse transcription-PCR approach (RT-PCR). Mass spectrometric (MS) and tandem mass spectrometric (MS/MS) analyses of an induction-active fraction showed the presence of several peptides of low molecular mass corresponding to fragments of αS1- and β-casein as well as β-lactoglobulin. The chemically synthesized αS1-casein fragment 37-55 (2,253.65 Da) was proven to be able to induce macedocin biosynthesis. This is the first time that milk protein degradation fragments are reported to exhibit a bacteriocin induction activity.

scholarly journals Calmodulin is a major component of extruded trichocysts from Paramecium tetraurelia.

1981 ◽  
Vol 91 (3) ◽  
pp. 860-865 ◽  
Author(s):  
J J Rauh ◽  
D L Nelson
Keyword(s):  
Heat Treatment ◽  
Amino Acid ◽  
Affinity Chromatography ◽  
Amino Acid Composition ◽  
The Other ◽  
Paramecium Tetraurelia ◽  
Whole Cells ◽  
Molecular Weights ◽  
Heat Stable ◽  
Composition Characteristic

Extruded trichocysts are composed of a family of proteins with molecular weights between 15,000 and 20,000. We have used heat treatment and affinity chromatography on fluphenazine-Sepharose to purify calmodulinlike proteins from whole cells and from extruded trichocysts. The purified protein from trichocysts is indistinguishable from that of whole cells; it is heat-stable, activates brain phosphodiesterase in a Ca++-dependent fashion, changes mobility on SDS polyacrylamide gels in the presence of Ca++, contains 1 mol of trimethyllysine/17 kdaltons, and has the amino acid composition characteristic of calmodulins. Calmodulin is a major component of purified, extruded trichocysts, of which it represents between 1 and 10% by mass. The other proteins of the trichocyst also resemble calmodulin in several properties. Possible roles for calmodulin in the Ca++-activated extrusion of trichocysts is discussed.

scholarly journals PERJALANAN ROHANI PERSPEKTIF KAUM SUFI

2017 ◽  
Vol 1 (2) ◽  
pp. 11-21
Author(s):  
Adnan Adnan
Keyword(s):  
Meaning Of Life ◽  
The Other ◽  
Spiritual Life ◽  
Spiritual Experiences ◽  
The Real ◽  
Spiritual Path ◽  
Final Goal ◽  
Life Journey ◽  
Pass Through ◽  
Sufi Order

Sufism as a spiritual life was frequently to be a return place for the tired man because of his life journey and an escape place for the pressed man. Beside that, actually sufism can strengthen the week individuals missing his self-existance. By sufism, they found the real meaning of life. In the teachings of sufi order, the seeker (salik) has to pass through spiritual path (thariqah) in order to know Allah as the Final Goal by passing a long journey and spiritual stations (maqamat) to improve their bad characteristics. This is significant to do for salikin, especially to make his inner empty, and then adorn and decorate it with all of good characteristics to reach higher and higher stations (maqamat). In the other hand, they found a religious-psycological experiences which is called ahwal to achive the spiritual experiences with Divine Reality (Haqiqah).

The use of heterologous radioimmunoassays for the measurement of follicle-stimulating hormone and luteinizing hormone concentrations in horse and donkey serum

1983 ◽  
Vol 99 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Valerie Urwin
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Cross Reactivity ◽  
Chorionic Gonadotrophin ◽  
Cross Reaction ◽  
The Other ◽  
Corpora Lutea ◽  
Serum Concentrations ◽  
Study Support ◽  
Baseline Levels

Heterologous double-antibody radioimmunoassays were developed for the measurement of FSH and LH concentrations in the serum of both horses and donkeys. The FSH assay employed a rabbit anti-ovine FSH serum which showed a complete lack of cross-reaction with equine chorionic gonadotrophin (eCG) and negligible cross-reaction with equine LH. The LH assay utilized an antiserum raised against highly purified eCG. This similarly showed negligible cross-reaction with equine FSH but its high cross-reactivity with eCG prevented the measurement of equine LH concentrations in serum when eCG was also present. In both assays serial dilutions of horse and donkey serum were parallel to the standard. The assays were used to monitor changes in serum concentrations of FSH and LH during the first 100 days of pregnancy in pony mares and jenny donkeys. In both species during pregnancy LH levels reached a peak 1–2 days after ovulation. They then decreased rapidly to baseline levels where they remained until days 35–40 when the commencement of eCG production prevented their further measurement. Serum FSH concentrations, on the other hand, continued to fluctuate markedly throughout the first 100 days of pregnancy in both the ponies and donkeys. Pronounced surges in FSH levels occurred at regular intervals in some animals but the pattern of release was quite irregular in the others. The results of this study support the concept that it is continued pituitary FSH release, not eCG secretion, which is responsible for stimulating the secondary follicles which develop during early equine pregnancy. However, it appears likely that it is the LH-like activity of eCG which causes the subsequent ovulation and/or luteinization of these secondary follicles to produce accessory corpora lutea.

Biological activity of partially purified low molecular weight luteinizing hormone binding inhibitor in porcine follicular fluids

1993 ◽  
Vol 128 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Nobuyoshi Kokawa ◽  
Mareo Yamoto ◽  
Kenichi Furukawa ◽  
Ryosuke Nakano
Keyword(s):  
Molecular Weight ◽  
Luteinizing Hormone ◽  
Competitive Inhibition ◽  
Biological Activities ◽  
Partial Purification ◽  
Low Molecular Weight ◽  
Dependent Manner ◽  
Hormone Binding ◽  
Dose Dependent ◽  
Follicular Fluids

We performed partial purification of low molecular weight luteinizing hormone binding inhibitor from porcine follicular fluids and examined its biological activities. Following ultrafiltration, gel filtration and anion exchange of the pooled porcine follicular fluids, low molecular weight fractions (500–10,000 MW) inhibited [125I]hLH binding to porcine granulosa cells in a dose-dependent manner. The binding inhibition kinetics study revealed that the luteinizing hormone binding inhibitor may indicate a non-competitive inhibition with [125I]hLH binding. In vitro bioassay using adult mouse testicular interstitial cells revealed that the partially purified luteinizing hormone binding inhibitor reduced ovine LH-stimulated testosterone and cAMP production in a dose-dependent manner, whereas the luteinizing hormone binding inhibitor did not affect basal production of testosterone and cAMP. The inhibitory activity was heat stable and did not disappear with activated charcoal adsorption. The results of the present study suggest that the luteinizing hormone binding inhibitor may play an important role as an ovarian non-steroidal regulator modulating the receptor binding of LH and LH-mediated steroidogenesis.

Active noise control for open windows

2021 ◽  
Vol 263 (3) ◽  
pp. 3097-3107
Author(s):  
Shahin Sohrabi ◽  
Peter Svensson ◽  
Teresa Pàmies Gómez ◽  
Jordi Romeu Garbi
Keyword(s):  
Control System ◽  
Noise Control ◽  
Active Noise Control ◽  
Sound Intensity ◽  
The Other ◽  
Active Noise ◽  
Open Window ◽  
Pass Through ◽  
Level Reduction ◽  
Suitable Location

Over the last decades, the applications of the active noise control system are broadened. In this study, the active noise control is modeled to reduce the noise pass through an open window. The objective is to define a suitable location for the control sources and error microphones to achieve more noise level reduction at the other side of the window. The performances of the active noise control system are calculated for two different arrangements: (1) the control sources on the edge of the opening and (2) the control sources distributed on the surface of the window. Furthermore, two cost functions are considered to model the noise control system including the minimization of the total squared pressure at cancellation points and the minimization of sound intensity at the surface of the aperture.

Studies on the Nature of the Plasma Erythropoietic Factor(s)

PEDIATRICS ◽  
1958 ◽  
Vol 21 (4) ◽  
pp. 581-581
Keyword(s):  
The Other ◽  
Normal Human Plasma ◽  
Erythropoietic Activity ◽  
Cellular Division ◽  
Humoral Factors ◽  
Hemoglobin Variability ◽  
Heat Stable ◽  
Hemopoietic Tissue ◽  
Blood Formation ◽  
Normal Human

In recent years the existence of a humoral factor or factors which stimulate erythropoietic activity has been demonstrated. The present paper reports further studies on the nature of this erythropoietic factor or factors. The author's studies indicate that there are at least two humoral erythropoietic facts. One is heat stable and appears to exert its effects upon cellular division of erythrocyte precursers in the marrow. The other factor is relatively thermolabile and exerts its effect through augmentation of incorporation of iron into hemoglobin. Variability in experimental results which have been reported in studies of the humoral erythropoietic factor may, in the authors' opinion, be due to differences in the material being studied (in content of these factors depending upon how the material being tested was prepared). These humoral factors are present in normal human plasma which suggests that they are involved in the maintenance of normal blood formation. Increased amounts of these factors in plasma in some anemias may be the result of local tissue hypoxia. In polycythemia vera the humoral factors may be of pathogenetic importance. The factors do not appear to be formed in hemopoietic tissue; the kidney has been suggested as a possible locus of formation.

Endocrine and local testicular regulation

2011 ◽  
pp. 1347-1353
Author(s):  
Ilpo Huhtaniemi
Keyword(s):  
Growth Factors ◽  
Luteinizing Hormone ◽  
Leydig Cell ◽  
Follicle Stimulating Hormone ◽  
Regulatory System ◽  
The Other ◽  
Seminiferous Tubules ◽  
Testicular Function ◽  
Cell Product ◽  
Stimulating Hormone

The testis has two functions, androgen production and spermatogenesis, and a key role in their regulation is played by the two pituitary gonadotropins, luteinizing hormone and follicle-stimulating hormone (FSH). Other hormones and growth factors also influence testicular function, often by modulating the gonadotropin effects. Moreover, a plethora of local paracrine and autocrine signals within the testis are known. The main testicular hormone, testosterone, a Leydig cell product, regulates spermatogenesis in seminiferous tubules in paracrine fashion. The other functions of testosterone are endocrine, occurring outside the testis. This chapter summarizes the main hormonal regulatory system of the testis, the hypothalamic–pituitary–testicular axis, and how its effects are modulated by other extratesticular hormones and local testicular factors.

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