Radioimmunoassay for 6-D-tryptophan analog of luteinizing hormone-releasing hormone: measurement of serum levels after administration of long-acting microcapsule formulations

Journal Article · Fri Mar 01 04:00:00 EST 1985 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.82.5.1547· OSTI ID:5828407

Mason-Garcia, M; Vigh, S; Comaru-Schally, A M; Redding, T W; Somogyvari-Vigh, A; Horvath, J; Schally, A V

A sensitive and specific radioimmunoassay for (6-D-tryptophan)luteinizing hormone-releasing hormone ((D-Trp/sup 6/)LH-RH) was developed and used for following the rate of liberation of (D-Trp/sup 6/)LH-RH from a long-acting delivery systems based on a microcapsule formulation. Rabbit antibodies were generated against (D-Trp/sup 6/)LH-RH conjugated to bovine serum albumin with glutaraldehyde. Crossreactivity with LH-RH was less than 1%; there was no significant cross-reactivity with other peptides. The minimal detectable dose of (D-Trp/sup 6/)LH-RH was 2 pg per tube. In tra- and interassay coefficients of variation were 8% and 10%, respectively. The radioimmunoassay was suitable for direct determination of (D-Trp/sup 6/)LH-RH in serum, permitting the study of blood levels of the analog after single injections into normal men and after one-a-month administration of microcapsules to rats. In men, 90 min after subcutaneous injection of 250 ..mu..g of the peptide, serum (D-Trp/sup 6/)LH-RH rose to 6-12 ng/ml. Luteinizing hormone was increased 90 min and 24 hr after the administration of the analog. Several batches of microcapsules were tested in rats and the rate of release of (D-Trp/sup 6/)LH-RH was followed. The improved batch of microcapsules of (D-Trp/sup 6/)LH-RH increased serum concentrations of the analog for 30 days or longer after intramuscular injection.

• Research Organization: Veterans Administration Medical Center, New Orleans, LA
• OSTI ID: 5828407
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 82:5; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALBUMINS
AMINO ACIDS
ANIMALS
ANTIBODIES
AROMATICS
AZAARENES
AZOLES
CARBOXYLIC ACIDS
CATTLE
DOMESTIC ANIMALS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HORMONES
INDOLES
ISOTOPE APPLICATIONS
MAMMALS
MAN
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDES
PRIMATES
PROTEINS
PYRROLES
RABBITS
RADIOASSAY
RADIOIMMUNOASSAY
RATS
RODENTS
RUMINANTS
TRACER TECHNIQUES
TRYPTOPHAN
VERTEBRATES