Conversion of radiolabeled human growth hormone into higher molecular weight moieties in human plasma in vivo and in vitro. [/sup 131/I tracer technique]

Journal Article · Mon Aug 01 04:00:00 EDT 1977 · Endocrinology; (United States)

OSTI ID:7285266

Beitins, I Z; Rattazzi, M C; MacGillivray, M H

Purified human growth hormone (hGH) was iodinated with /sup 131/I ((/sup 131/I)iodo-hGH) and purified on Sephadex G-100. The monomeric (/sup 131/I)iodo-hGH (mol wt about 20,000 daltons) was injected as a bolus iv in healthy volunteers and plasma obtained at 10,20, and 40 min. Then continuous infusion with (/sup 131/I)iodo-hGH was started and further plasma samples obtained after 120 min when a plateau of immunoreactive hGH (IR-hGH) had been attained. In one individual the bolus injection was followed further to 60 and 120 min. Fresh plasma was immediately chromatographed on Sephadex G-100 and the IR-hGH profiles evaluated. In all instances following iv injection, larger and occasionally smaller immunoreactive moieties than the injected (/sup 131/I)iodo-hGH appeared. When (/sup 131/I)iodo-hGH was incubated at 37 C with fresh human plasma from 4 different individuals from 10 to 120 min, the larger molecular weight forms, noted in the in vivo studies, were again demonstrable. Only the monomeric (/sup 131/I)iodo-hGH was found when (/sup 131/I)iodo-hGH was incubated at 37 C for 120 min with human serum albumin or gamma globulin.

• Research Organization: State Univ. of New York, Buffalo
• OSTI ID: 7285266
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 101:2; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD PLASMA
BODY FLUIDS
DAYS LIVING RADIOISOTOPES
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE 131
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLING
MOLECULAR WEIGHT
NUCLEI
ODD-EVEN NUCLEI
PEPTIDE HORMONES
PITUITARY HORMONES
RADIOISOTOPES
STH
TRACER TECHNIQUES