A radioimmunoassay for oncorhynchid growth hormone targeted to the physiological range

1994 ◽  
Vol 72 (10) ◽  
pp. 1155-1161 ◽  
Author(s):  
Timothy J. Kieffer ◽  
Phil J. Schieldrop ◽  
Ewen McLean ◽  
Edward M. Donaldson ◽  
John C. Brown
Keyword(s):  
Growth Hormone ◽  
Rainbow Trout ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Full Range ◽  
Rabbit Antiserum ◽  
Hormone Treatment ◽  
Cross Reactivity ◽  
Standard Curve ◽  
Wide Range

This study describes the development of an oncorhynchid growth hormone (GH) radioimmunoassay using recombinant chum salmon GH (rsGH) and a rabbit antiserum (TJK-1) raised against this recombinant material. The assay was designed to measure the wide range of circulating immunoreactive GH (IRGH) levels in Pacific salmonids, resulting in a standard curve capable of accurately determining plasma levels, of IRGH from 0.5 to 250 ng/mL without dilution. The assay ED50 and ED90 values averaged 13.1 and 0.5 ng/mL, respectively. This radioimmunoassay specifically recognizes oncorhynchid IRGH, showing no cross-reactivity with recombinant porcine and bovine GH, or natural chum salmon prolactin at concentrations up to 10 μg/mL. Curves approximately parallel to the standard curve were obtained with purified natural coho salmon GH and plasma from chinook salmon. Recovery of rsGH from plasma was complete over the full range of the standard curve. Intra- and inter-assay coefficients of variation were 6.0 and 12.9%, respectively. Plasma IRGH levels in fed coho salmon were 30.6 ± 5.3 ng/mL, while those in fish starved for 2 weeks were 132.9 ± 53.9 ng/mL. Starvation for an additional 4 weeks had no significant effect. Plasma IRGH levels in control rainbow trout injected with saline were significantly higher 45 min post-injection. In contrast, fish injected with recombinant porcine GH exhibited no elevation in IRGH. It is speculated that exogenous GH inhibits the production of endogenous GH.Key words: recombinant chum growth hormone, coho growth hormone, rainbow trout growth hormone, growth hormone treatment.

Growth hormone therapy for the growth-hormone deficient child

2011 ◽  
pp. 1073-1083
Author(s):  
Jan M. Wit ◽  
Wilma Oostdijk
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Present Situation ◽  
Hormone Treatment ◽  
Hormone Deficiency ◽  
Evidence Based ◽  
Test Parameters ◽  
Wide Range ◽  
Deficient Child

In the five decades in which growth hormone has been prescribed for children with growth hormone deficiency (GHD) there has been definite progress, but on the other hand there is still insufficient evidence to answer many basic questions. From an evidence-based perspective the present situation with respect to growth hormone treatment for GHD is therefore far from optimal. First, the diagnosis GHD cannot be defined precisely, because there is a wide range of growth hormone secretion in normally growing individuals, which overlaps with the range observed in children clinically suspected of GHD. Furthermore, all test parameters available have serious drawbacks (1). Therefore, the term GHD stands for a heterogeneous group of congenital or acquired deficiencies (or apparent deficiency). Most patients have an idiopathic isolated GHD, but particularly in that subgroup retesting at the end of growth often shows a normal stimulated growth hormone peak. Of the acquired (organic) GHD, malignancies are the most frequent aetiology, but the incidence of traumatic brain injury may be underestimated.

Radioimmunoassay of canine growth hormone

1981 ◽  
Vol 98 (4) ◽  
pp. 514-520 ◽  
Author(s):  
J. E. Eigenmann ◽  
R. Y. Eigenmann
Keyword(s):  
Growth Hormone ◽  
Rhesus Monkeys ◽  
Low Dose ◽  
Cross Reactivity ◽  
Gel Chromatography ◽  
Assay Sensitivity ◽  
Standard Curve ◽  
Straight Line ◽  
Plasma Gh ◽  
Line Fitting

Abstract. A sensitive radioimmunoassay (RIA) for canine growth hormone (GH) was developed. Antibodies were elicited in rhesus monkeys. One antiserum exhibited a working titer at a dilution of 1:500000. Radioiodination was performed enzymatically employing lactoperoxidase. Logit-log transformation and least squares fitting resulted in straight line fitting of the standard curve between 0.39 and 50 ng/ml. Formation of largemolecular [12SI]GH during storage caused diminished assay sensitivity. Therefore [125I]GH was re-purified by gel chromatography. Using this procedure, high and reproducible assay sensitivity was obtained. Tracer preparations were used for as long as 3 months after iodination. Diluted plasma from normal and acromegalic dogs resulted in a dose-response curve parallel to the standard curve. Canine prolactin exhibited a cross-reactivity of 2%. The within-assay coefficient of variation (CV) was 3.8 and the between-assay CV was 7.2%. Mean plasma GH concentration in normal dogs was 1.92 ± 0.14 ng/ml (mean ± sem). GH levels in acromegalic dogs were appreciably higher. Insulin-induced hypoglycaemia, arginine and ornithine administration resulted in inconsistent and sluggish GH increment. A better response was obtained by injecting a low dose of clonidine. Clonidine administration to hypopituitary dogs resulted in absent or poor GH increment.

Somatolactin, a novel pituitary protein: purification and plasma levels during reproductive maturation of coho salmon

1992 ◽  
Vol 133 (3) ◽  
pp. 393-403 ◽  
Author(s):  
M. Rand-Weaver ◽  
P. Swanson ◽  
H. Kawauchi ◽  
W. W. Dickhoff
Keyword(s):  
Salmo Salar ◽  
Chinook Salmon ◽  
Plasma Levels ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Cross Reactivity ◽  
Standard Curve ◽  
Reproductive Maturation ◽  
Final Maturation ◽  
Highly Correlated

ABSTRACT Somatolactin (SL), a newly discovered fish pituitary protein belonging to the GH/prolactin family, was isolated from coho salmon (Oncorhynchus kisutch). Antibodies were raised to purified coho SL, and a homologous radioimmunoassay was developed and validated. The assay was specific for SL as indicated by the absence of cross-reactivity with coho salmon GH, gonadotrophins I and II and less than 0·2% cross-reaction to prolactin. Serial dilutions of plasma and pituitary extracts from Oncorhynchus species including coho salmon, chinook salmon and rainbow trout were parallel to the coho salmon SL standard curve. Displacement curves for dilutions of Atlantic salmon (Salmo salar) plasma, but not pituitary extract were parallel to the standards. Plasma levels of SL were measured in coho salmon throughout the final year of reproductive maturation. During the period of gonadal growth, plasma SL levels increased and were highly correlated to oestradiol levels in females and 11-ketotestosterone levels in males. Peak levels of SL were observed at the time of final maturation and spawning in both sexes. It is hypothesized that SL may regulate some physiological aspect of reproduction. Journal of Endocrinology (1992) 133, 393–403

Growth hormone receptors in the liver and osmoregulatory organs of rainbow trout: characterization and dynamics during adaptation to seawater

1991 ◽  
Vol 130 (3) ◽  
pp. 425-433 ◽  
Author(s):  
T. Sakamoto ◽  
T. Hirano
Keyword(s):  
Growth Hormone ◽  
Rainbow Trout ◽  
Binding Sites ◽  
Chum Salmon ◽  
Hormone Receptors ◽  
Sea Water ◽  
Specific Binding ◽  
Head Kidney ◽  
Scatchard Analysis ◽  
Single Class

ABSTRACT Specific binding sites for chum salmon growth hormone (sGH) were identified in the membranes obtained from tissues of rainbow trout. Specific binding of 125I-labelled sGH (% per mg protein) was found in the liver (37%), ovary (6%), brain (6%), gill (4%), intestine (4%) and posterior body kidney (4%). Specific binding was not significant in head kidney, anterior body kidney, spleen, heart, skeletal muscle or skin. Scatchard analyses demonstrated the presence of a single class of high-affinity low-capacity receptors in the liver, gill, intestine and kidney. The association constants for the membranes from liver, gill, intestine and kidney were of the same order (1 litre/nmol). Chum salmon prolactin did not inhibit the binding of 125I-labelled sGH to receptors in the liver, gill, intestine and kidney. Transfer of rainbow trout from fresh water to 80% seawater evoked a rise in plasma concentration of GH and a significant decrease in the GH binding to the liver membranes after 1 day. Binding in the gill and kidney was not altered significantly. Membranes were treated with 4 mol MgCl2/l to remove bound GH from the receptors, and the results indicated that the reduction in binding in the liver after transfer to sea-water was probably due to receptor occupancy by increased endogenous GH. The occupancy of liver GH-binding sites was maximal 4 days after transfer. Total (MgCl2-treated) binding sites in the liver increased significantly 14 days after transfer. Scatchard analysis indicated that receptors were altered in capacity without changes in binding affinity. Although GH may also directly affect osmoregulatory organs through their GH receptors, the present results indicate the likelihood of at least partial mediation by the liver of the seawater-adapting action of GH in the rainbow trout. Journal of Endocrinology (1991) 130, 425–433

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