Effect of naloxone hydrochloride on osteogenesis in chick embryos

Naloxone hydrochloride, an opioid receptors blocker, was administered to chick embryos. Morphological analysis of femoral bones of embryos showed an appreciable increase in the thickness of the perichondral bone cuff in the tubular bone diaphyses and increased mitotic activity in the zone of proliferating young cartilage of the epiphyseal plate.