Endocrinology: The effect of nafarelin on human plasma adrenocorticotrophic hormone and cortisol concentrations

1993 ◽  
Vol 8 (10) ◽  
pp. 1593-1597
Author(s):  
C.E. Overton ◽  
S.H. Kennedy ◽  
D.E. Egan ◽  
D.H. Barlow
Keyword(s):  
Human Plasma ◽  
Adrenocorticotrophic Hormone

DEVELOPMENT OF A SPECIFIC EXTRACTED RADIOIMMUNOASSAY FOR METHIONINE ENKEPHALIN IN HUMAN PLASMA AND CEREBROSPINAL FLUID

1980 ◽  
Vol 86 (2) ◽  
pp. 231-243 ◽  
Author(s):  
VICKY CLEMENT-JONES ◽  
P. J. LOWRY ◽  
LESLEY H. REES ◽  
G. M. BESSER
Keyword(s):  
Cerebrospinal Fluid ◽  
Human Plasma ◽  
Breakdown Product ◽  
Adrenocorticotrophic Hormone ◽  
Purification Method ◽  
Methionine Enkephalin ◽  
High Affinity ◽  
Methionine Residue ◽  
Unique Specificity ◽  
Repeated Samples

A sensitive extracted radioimmunoassay for methionine enkephalin (met-enkephalin) has been developed which allows measurement of its concentration in human plasma and cerebrospinal fluid (CSF). The first evidence for the existence of met-enkephalin in the circulation of man is described and its presence in CSF confirmed. The susceptibility of the methionine residue in met-enkephalin to undergo oxidation to the methionine sulphoxide analogue was utilized. All extracted samples were oxidized by hydrogen peroxide before assay and this allowed measurement of total met-enkephalin. The assay had unique specificity with no cross-reaction with leucine enkephalin, purified human β-endorphin or β-lipotrophin (β-LPH). A purification method for radio-iodinated enkephalin has been developed with octadecasilyl-silica (ODS-silica) (10 μm) yielding a high-affinity monoiodinated tracer stable on storage for up to 3 months at 4 °C. A method to extract met-enkephalin from acidified plasma or CSF has been developed with larger particle size ODS-silica (35–70 μm) suitable for extracting repeated samples. Met-enkephalin immunoreactivity was detectable in plasma of all subjects tested and ranged from 14 to 140 pg/ml. In CSF, however, the range was 5–29 pg/ml. Met-enkephalin immunoreactivity was not generated by incubating exogenous or endogenous β-LPH and β-endorphin in plasma or CSF. Two hypopituitary subjects and one dexamethasone-suppressed subject, all with undetectable immunoreactive plasma adrenocorticotrophic hormone and NH2- and CO2H-terminal β-LPH, had measurable met-enkephalin in their plasma suggesting met-enkephalin was not of pituitary origin nor a breakdown product of secreted β-LPH or β-endorphin.

A RADIOIMMUNOASSAY FOR β-MELANOCYTE-STIMULATING HORMONE IN HUMAN PLASMA

1973 ◽  
Vol 58 (2) ◽  
pp. 263-273 ◽  
Author(s):  
A. J. THODY ◽  
N. A. PLUMMER
Keyword(s):  
Human Plasma ◽  
Porous Glass ◽  
Simple Technique ◽  
Cross Reactivity ◽  
Bilateral Adrenalectomy ◽  
Normal Male ◽  
Adrenocorticotrophic Hormone ◽  
Melanocyte Stimulating Hormone ◽  
Male Subjects ◽  
Stimulating Hormone

SUMMARY A method is described for the radioimmunoassay of β-melanocyte-stimulating hormone (β-MSH) in human plasma. It was capable of detecting 20–30 pg β-MSH and was unaffected by the presence of α-MSH and human adrenocorticotrophic hormone. However, cross-reactivity did occur with β-glutamyl MSH (porcine). A simple technique employing porous glass (Florisil) was used to extract β-MSH from plasma. In normal male subjects plasma β-MSH levels ranged from 21 to 133 pg/ml. In patients receiving cortisol therapy for Addison's disease slightly elevated levels were found. Much higher levels were found in patients who had undergone bilateral adrenalectomy as treatment for Cushing's disease.

ESTIMATION AND IDENTIFICATION OF FREE AND CONJUGATED CORTICOSTEROIDS IN HUMAN PLASMA

1960 ◽  
Vol 21 (3) ◽  
pp. 303-314 ◽  
Author(s):  
MARION B. R. GORE ◽  
D. N. BARON
Keyword(s):  
Human Plasma ◽  
Resting State ◽  
Quantitative Measure ◽  
Plasma Samples ◽  
Adrenocorticotrophic Hormone ◽  
Before And After ◽  
Main Component ◽  
Free Plasma ◽  
Normal Controls

SUMMARY 1. An examination has been made of the free and glucuronide-conjugated corticosteroids in the plasma of normal controls and of patients before and after hypophysectomy. Quantitative measure of the free plasma corticosteroid level 72 hr after withholding cortisone from a hypophysectomized patient (cortisone withdrawal test) is a useful index of completeness of hypophysectomy. Qualitative examination failed to detect corticosteroids in these patients. 2. In all plasmas examined (controls and patients in resting state and after adrenocorticotrophic hormone (ACTH)) the main component of the free corticosteroid fraction is cortisol. In 50% of the plasma samples cortisone was detected. Even after ACTH only occasional traces of corticosterone were detected by the method used in this study. 3. In the glucuronide-conjugated fraction of plasma from subjects in the resting state three compounds, concluded to be tetrahydrocortisol (THF)†, tetrahydrocortisone, and allo-THF†, were regularly seen. After ACTH other material was detected in this fraction which is considered to be tetrahydrocorticosterone (THB), tetrahydro 11-deoxycortisol (THS) and allo-THB. Administration of oral cortisone to hypophysectomized patients did not increase the amounts of THB, THS or allo-THB in the plasma.

A SENSITIVE BIOASSAY FOR ADRENOCORTICOTROPHIC HORMONE IN HUMAN PLASMA

1972 ◽  
Vol 1 (3) ◽  
pp. 219-233 ◽  
Author(s):  
J. CHAYEN ◽  
N. LOVERIDGE ◽  
J. R. DALY
Keyword(s):  
Human Plasma ◽  
Adrenocorticotrophic Hormone

Performances of an Artificial Reagent for the One-stage Factor IX Assay

1975 ◽  
Vol 33 (03) ◽  
pp. 547-552 ◽  
Author(s):  
L Meunier ◽  
J. P Allain ◽  
D Frommel
Keyword(s):  
Human Plasma ◽  
Factor Ix ◽  
Severe Haemophilia ◽  
Normal Human Plasma ◽  
Haemophilia B ◽  
One Stage ◽  
Normal Human ◽  
The One

SummaryA mixture of adsorbed normal human plasma and chicken plasma was prepared as reagent for factor IX measurement using a one-stage method. The substrate was found to be specific for factor IX. Its performances tested on samples displaying factor IX activity ranging from <l%–2,500% compared favorably with those obtained when using the plasma of severe haemophilia B patients as substrate.

Plasma Components which Interfere with Ristocetin-induced Platelet Aggregation

1975 ◽  
Vol 33 (03) ◽  
pp. 540-546 ◽  
Author(s):  
Robert F Baugh ◽  
James E Brown ◽  
Cecil Hougie
Keyword(s):  
Platelet Aggregation ◽  
Human Plasma ◽  
Plasma Proteins ◽  
Binding Protein ◽  
Plasma Heating ◽  
Protein S ◽  
Fold Increase ◽  
Normal Human Plasma ◽  
Preliminary Examination ◽  
Normal Human

SummaryNormal human plasma contains a component or components which interfere with ristocetin-induced platelet aggregation. Preliminary examination suggests a protein (or proteins) which binds ristocetin and competes more effectively for ristocetin than do the proteins involved in ristocetin-induced platelet aggregation. The presence of this protein in normal human plasma also prevents ristocetin-induced precipitation of plasma proteins at levels of ristocetin necessary to produce platelet aggregation (0.5–2.0 mg/ml). Serum contains an apparent two-fold increase of this component when compared with plasma. Heating serum at 56° for one hour results in an additional 2 to 4 fold increase. The presence of a ristocetin-binding protein in normal human plasma requires that this protein be saturated with ristocetin before ristocetin-induced platelet aggregation will occur. Variations in the ristocetin-binding protein(s) will cause apparent discrepancies in ristocetin-induced platelet aggregation in normal human plasmas.

Studies on the Fibrinolytic System in Human Plasma: Quantitative Determination of Plasminogen Activators and Proactivators

1979 ◽  
Vol 41 (02) ◽  
pp. 365-383 ◽  
Author(s):  
C Kluft
Keyword(s):  
Pilot Study ◽  
Plasma Level ◽  
Human Plasma ◽  
Plasminogen Activators ◽  
Venous Occlusion ◽  
Quantitative Information ◽  
Optimal Recovery ◽  
Dextran Sulphate ◽  
Baseline Levels

SummaryEffects due to plasma plasminogen activators and proactivators are usually studied in assay systems where inhibitors influence the activity and where the degree of activation of proactivators is unknown. Quantitative information on activator and proactivator levels in plasma is therefore not availableStudies on the precipitating and activating properties of dextran sulphate in euglobulin fractionation presented in this paper resulted in the preparation of a fraction in which there was optimal recovery and optimal activation of a number of plasminogen activators and proactivators from human plasma. The quantitative assay of these activators on plasminogen-rich fibrin plates required the addition of flufenamate to eliminate inhibitors. The response on the fibrin plates (lysed zones) could be coverted to arbitrary blood activator units (BAU). Consequently, a new activator assay which enables one to quantitatively determine the plasma level of plasminogen activators and proactivators together is introduced.Two different contributions could be distinguished: an activity originating from extrinsic activator and one originating from intrinsic proactivators. The former could be assayed separately by means of its resistance to inhibition by Cl-inactivator. Considering the relative concentrations of extrinsic and intrinsic activators, an impression of the pattern of activator content in plasma was gained. In morning plasma with baseline levels of fibrinolysis, the amount of extrinsic activator was negligible as compared to the level of potentially active intrinsic activators. Consequently, the new assay nearly exclusively determines the level of intrinsic activators in morning plasma. A pilot study gave a fairly stable level of 100 ± 15 BAU/ml (n = 50). When fibrinolysis was stimulated by venous occlusion (15 min), the amount of extrinsic activator was greatly increased, reaching a total activator level of 249 ± 27 BAU/ml (n = 7).

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