IMMUNOHISTOCHEMICAL AND RT-PCR DETECTION OF NA-DEPENDENT INORGANIC-PHOSPHATE COTRANSPORTER (NAPI-2) IN RAT-BRAIN()

Expression of a renal Na+-dependent inorganic phosphate (P-i) cotransp orter (NaPi-2) was studied in rat forebrain with reverse transcription and polymerase chain reaction (RT-PCR) and immunohistochemistry. RT-P CR analysis for total RNA from whole brain and sequencing of the PCR p roducts showed expression of NaPi-2 mRNA in the brain. Immunohistochem ical analysis revealed NaPi-2 staining in many nonpyramidal neurons of all six layers throughout neocortical areas and in neurons of proisoc ortical and periallocortical areas. NaPi-2-immunoreactive neurons were also detectable in the piriform cortex, hippocampal formation, caudat e-putamen, amygdaloid nuclei and lateral geniculate nucleus. Furthermo re, NaPi-2 staining was shown in ependymal cells and microvascular end othelial cells. The present results suggest that NaPi-2 is synthesized within the brain and involved in maintaining P-i homeostasis of certa in neurons and/or the entire brain. (C) 1997 Elsevier Science B.V.