Abstract
The efficacy of periodic administration of Decapeptyl microcapsules upon symptoms of PP has been previously reported (Roger et al., ESPE meeting 1984, abstract 22). A sensitive radioimmuno assay of the analogue was developped using an antiserum raised in rabbit which exhibited unsignificant cross reactivity with native LH-RH or LH-RH fragments (Mason-Garcia et al.,Proc.Natl. Acad. Sci., USA, in press). Iodinated D-Trp-6-LH-RH was used as a tracer. Fifty μl antiserum diluted at 1/2500 , 50 μl tracer, 100 μl standard (or unknown plasma), 100 μl plasma pool (or phosphate buffer 0.01 M, pH 7.5) were incubated for 24 h. Free and bound were separated by PEG. NSB of the plasma pool and of 40 different child samples were respectively 6.2± 0.4 and 6.3± 0.4% (mean±SD). Bo was 20%. Intraassay CV were 12 and 7% for mean plasma levels of 100 and 370 pg/ml respectively. The detec tion limit was 57 pg/ml. Five children received intramuscularly (IM) on days 1, 21 and every 28 days thereafter, 1.5 mg Decapeptyl microcapsules. Plasma levels were on days 3, 7, 14, and 21 (pg/ml, mean±SEM) 312±57, 242±65, 145±78 and 171±87. Decapeptyl was undetectable in most of samples on day 28 after injection. This study demonstrates that significant Decapeptyl levels are maintained for at least 21 days after a single IM injection.
