Postnatal development of peripheral-type benzodiazepine receptors in rat brain and peripheral tissues.

We examined the postnatal development of peripheral-type benzodiazepine receptors (PBRs), labelled with [3H]PK 11195, in rat brain and peripheral tissues. Specific [3H]PK 11195 binding exhibited a heterogeneous patterns of postnatal development in the rat: three patterns of increase, decrease and no change. Hence, the density of the PBRs can be independently regulated in each tissue during postnatal development, and the postnatal alterations in the density might be parallel with the functional activities coupled to the receptors.