Radioimmunoassay of Human Growth Hormone Using the Double Antibody Technique

Melani, F; Gröschel‐Stewart, Ute; Lawecki, J

doi:10.1530/acta.0.0570549

Cited by 15 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Serum for GH and diazepam determination was centrifuged at 4 °C within one hour and stored at -20 °C until analysis. Blood glucose was determined by the method of Hoffman (1937) and serum GH by double antibody radioimmunoassay (Melani, Groeschel-Schwart and Lawecki 1968) employing standard GH preparation WHO 66/217, 125 I hGH and reagents supplied by Biodata International, Switzerland (code 1703 kits). The sensitivity of GH assay was 0.4 ng/ml and interassay variation for reference sera of 5.0 ng/ml were 4.5 percent.…”

Section: Methodsmentioning

confidence: 99%

Diazepam Test of Growth Hormone Secretion

Kannan¹

1981

Horm Metab Res

View full text Add to dashboard Cite

Diazepam induced growth hormone (GH) secretion was studied in six healthy subjects, twenty hypopituitary and five acromegalic patients. Plasma GH, blood glucose and diazepam levels were determined. Diazepam (0.2 mg/kg b.w.) consistently induced GH secretion in control and acromegalic subjects. Oral diazepam produced a peak level (21.2 ± 3.2 ng/ml) at 40 minutes in six control subjects and GH returned to basal levels at 90 minutes (3.8 ±1.2 ng/ml). In twenty hypopituitary subjects with basal GH level of 1.7 ± 0.5 ng/ml, the peak GH after oral diazepam (4.3 ±1.2 ng/ml) was significantly blunted (p < 0.001). In four acromegalic patients, the elevated basal GH level (29.6 ± 9.0 ng/ml) increased further to a peak at 40 minutes (92.7 ± 15.1 ng/ml) and remained high up to 90 minutes (p < 0.001). No GH response was obtained in three hypopituitary and one acromegalic patients.The peak GH level at 20 minutes after intramuscular injection of diazepam (10 mg) was 14.3 ± 3.7 ng/ml in control, 3.0 ± 0.4 ng/ml in five hypopituitary and 54.4 ± 13.1 ng/ml in acromegalic subjects. No significant change in blood glucose was seen after diazepam stimulation. A comparison was made between the GH responses to diazepam and insulin induced hypoglycemia in hypopituitarism and acromegaly. Both tests caused adequate release of GH from the pituitary gland in five control subjects who had normal GH reserve. The peak GH responses of the two tests were similar in magnitude in control subjects and were correlated (r = 0.77; p < 0.001). In five hypopituitary subjects both the tests failed to evoke a satisfactory GH response thus confirming the deficiency of GH. In four acromegaly subjects, diazepam raised serum GH to a higher level than insulin induced hypoglycemia. Diazepam stimulation does not require prior preparation of the patient and is relatively free of side effects. Consequently, we suggest that diazepam induced GH secretion is a simple, reliable test of pituitary function useful in the assessment of hypopituitarism and acromegaly.

show abstract

Section: Methodsmentioning

confidence: 99%

Diazepam Test of Growth Hormone Secretion

Kannan¹

1981

Horm Metab Res

View full text Add to dashboard Cite

show abstract

“…These efforts have included attempts to inactivate complement by heating samples and by adding chelating agents (Morgan et al 1964;Sheldon Sc Taylor 1965;Grant 1968). In addition, neutral antigen-antibody precipi¬ tates have been added to aid in collection of the precipitate (Quabbe 1969), »hormone-free« serum has been added such that all tubes contained the same volume of serum (Odell 1969;Goodfriend 1969;Thorell 1969), the possibility of cross-reactions between the gamma globulin in the first antibody and the gamma globulin in the sample has been studied (Hales Se Rändle 1963; Mor¬ gan et al 1964;Kuzuya Sc Samols 1964;Welborn Se Fraser 1965), and samples of serum have been diluted such that serum components do not interfere (Morgan 8c Lazarow 1963;Welborn 8c Fraser 1965;Melani et al 1968). …”

Section: Use Of Post-precipitationmentioning

confidence: 99%

Radioimmunoassays Employing Double Antibody Techniques

Midgley

Rebar

Niswender

1969

Acta Endocrinologica

View full text Add to dashboard Cite

Double antibody methods are applicable to all radioimmunoassay systems. At least three approaches exist. The first, in which immunoprecipitating serum is used to precipitate soluble antigen-antibody complexes, is the most commonly used. Since the effects of interfering factors, especially those present in serum, become minimal as equilibrium is approached, care must be taken to insure that the period of incubation is of sufficient length for the immunoprecipitation reaction to reach equilibrium. In general, all efforts should focus on achieving reaction conditions which maximize stability and optimize immunoprecipitation. A second approach involves use of the first antiserum in an insolubilized form after prior precipitation with the immunoprecipitating antiserum. This approach is attractive since most non specific factors cannot interfere with the immunoprecipitation step to a significant extent once the formation of antigen-antibody aggregates is well underway. The third approach, in which immunoprecipitating antiserum is conjugated to a solid matrix, in principle represents a more ideal method of separating bound hormone from free. If this approach is ever to be utilized, a method of conjugating antiserum to a suitable matrix such that the antibody retains most of its immunoreactivity must be devised.

show abstract

“…Plasma insulin was measured by the doubleantibody radioimmunoassay method of Hales and Randle (18) with all reagents supplied in a kit (Amersham, Arlington Heights, Ill.). Growth hormone was measured by the double-antibody radioimmunoassay described by Melani et al (19) with all reagents supplied in a kit (Serone Labs. Inc., Braintree, Mass.).…”

mentioning

confidence: 99%

Blood Plasma Levels of Cortisol, Insulin, Growth Hormone and Somatomedin in Children with Marasmus, Kwashiorkor, and Intermediate Forms of Protein-Energy Malnutrition

Smith¹,

Latham²,

Azubuike³

et al. 1981

Experimental Biology and Medicine

View full text Add to dashboard Cite

Plasma insulin, growth hormone, somatomedin, free and bound cortisol, and serum albumin were measured in human infants with protein-energy malnutrition and in age-matched control subjects. Insulin and somatomedin were reduced, growth hormone and free and total cortisol were elevated in malnourished infants. Free cortisol and somatomedin were negatively correlated (r = -0.78) and somatomedin and percentage weight deficit were negatively correlated in marasmus (r = -0.62) and kwashiorkor (r = -0.68). It is suggested that elevated plasma-free cortisol as well as depressed plasma insulin in protein-energy malnourished infants is partially responsible for the depressed plasma somatomedin and reduced protein synthesis and growth in children. 607 0037-972718 11080607-05$01 .OO/O

show abstract

Radioimmunoassay of Human Growth Hormone Using the Double Antibody Technique

Cited by 15 publications

References 0 publications

Diazepam Test of Growth Hormone Secretion

Diazepam Test of Growth Hormone Secretion

Radioimmunoassays Employing Double Antibody Techniques

Blood Plasma Levels of Cortisol, Insulin, Growth Hormone and Somatomedin in Children with Marasmus, Kwashiorkor, and Intermediate Forms of Protein-Energy Malnutrition

Contact Info

Product

Resources

About