RESUMEN
Objective To study the expression of plasma membrane Ca2 + -ATPase isoforms 1 -4 and the splice variants at sites A and C in the neonatal rat vestibular organ.Methods Ten rats at postnatal 2 days (P2 ) were decapitated and their vestibular organs (macula utriculi and macula sacculi)were isolated.The total proteins of the vestibular organs were extracted.The expression of PMCA1-4 splice variants at sites A and C was detected by RT-PCR.Results The splice variants of PMCA1-4 at sites A and C in macula utriculi and macula sacculi of neo-natal rat vestibular organs were PMCA1x/b,PMCA2w/(a,b),PMCA3z/(a,b,c)and PMCA4 (x,z)/b.Conclusion The splice variants at sites A and C among PMCA1,PMCA2,PMCA3 and PMCA4 were different in the vestibu-lar organs of neonatal rats,which could be explained that macula utriculi and macula sacculi had different require-ments of Ca2 + turning for these PMCA isoforms.