title: Differential postnatal development of mu-, delta- and kappa-opioid binding sites in rat brain.
abstract: With selective labelling techniques and analysis of saturation curves it is shown that in rat brain the concentrations of mu-, delta- and kappa-binding sites increase differentially during postnatal development. There are no changes in the binding affinities. The concentration (pmol/g brain) of kappa-sites are first to reach adult levels, namely between 7 and 14 days after birth. Adult levels of mu-sites are attained between 14 and 21 days after birth. The most striking finding is that development of delta-sites, which are not detectable 3 days after birth by the method used, lags markedly behind that of mu- and kappa-sites. The profile of development in rat brain is compared to that found previously in mouse brain.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004723:Endorphins