LH-RH analogs, substituted in position 6 by D-tryptophane, D-serine(tBu), D-leucine or D-alanine induce a strong stimulation of the gonadotrophs, followed by a desensitization of the LH-RH receptors, ...which leads to a blockade of the gonadotropin secretion and to a hypogonadism. A delayed release preparation of D-Trp-6-LH-RH (Decapeptyl in microcapsules), designed to release the peptide for 28 days after intramuscular injection, was given to 69 girls and 18 boys with precocious puberty. In both, plasma levels of gonadotropins and gonadal steroids were suppressed within 3 weeks, whilst pituitary responses to LH-RH were almost abolished within 7 weeks. A significant improvement of secondary sex characteristics, as well as gonadal size, was obvious within 6 months. Growth velocity was markedly lowered and, more, in most of children, bone maturation was blocked. This study shows that Decapeptyl in microcapsules is more rapidly and more constantly efficient than LH-RH agonists given discontinuously by subcutaneous or intranasal route.
