Radioimmunoassay for hexarelin, a peptidic growth hormone secretagogue, and its pharmacokinetic studies
1995; Elsevier BV; Volume: 16; Issue: 7 Linguagem: Inglês
10.1016/0196-9781(95)02022-o
ISSN1873-5169
AutoresMarie Roumi, Vincent Lenaerts, F. Boutignon, Patrick Wüthrich, Romano Deghenghi, Monique Bellemare, Albert Adam, Huy Ong,
Tópico(s)Infant Nutrition and Health
ResumoA radioimmunoassay (RIA) method for hexarelin, a peptidic growth hormone secretagogue, has been developed and applied to pharmacokinetic studies in dogs following an IV dose of 1 microgram/kg, and three SC doses of 1, 10, and 100 micrograms/kg. The sensitivity of the assay was determined to be 1.34 fmol/assay. Cross-reactivity of the antiserum with nine hexarelin analogues was less than 1% upon modification of positions 3, 4, or 5 of the peptide. No apparent cross-reaction with endogenous hexarelin metabolites were observed. Intra- and interassay coefficients of variation were less than 3% and 4%, respectively. Intravenous bolus pharmacokinetics of hexarelin displayed a high terminal half-life of 120 min, a fractional plasma clearance of 4.28 ml/min/kg, and a volume of distribution at steady state of 387.7 ml/kg. Following SC administration of hexarelin, despite the increase in dose administered, both clearance (3.93-5.17 ml/min/kg) and volume of distribution (316-544 ml/kg) parameters remained constant over the dose range studied.
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