[Expression of plasma membrane Ca²(+)-ATPase isoform 2 in spiral ganglion cells of newborn rats].

Objective To study the expression of plasma membrane Ca2＋ -ATPase isoform 2 （PMCA2） in spiral ganglion cell （SGC） from inner ear of newborn rats and further check PMCA2 splice variants at site A and C. Methods Spiral ganglion tissues isolated from cochlea of newborn rats （P3-P4） were cultured and identified in vitro. The cochlea of newborn rats （ P3-P4 ） were isolated and cut into frozen sections. The expression of PMCA2 was detected by immunofluorescence analyses. The SGC cultured in 4 wells of the 6-well culture plate were collected and the total RNA was extracted by Trizol and reverse transcribed to eDNA. The site A and C splice variants of PMCA2 were respectively checked by nested PCR and common PCR. Results The SGC grew well with good refraction and showed positive immunoreactivity for neuronal marker NF-200. Strong green fluorescence could be seen in cytomembrane, cytoplasm and neuritis, as well showing SGC immunoreactivity for PMCA2 antibody. In the cochlear sections, the spiral ganglion tissues were strongly stained by PMCA2. PMCA2z was present at splice site A, but PMCA2b and PMCA2c were present at splice site C. Conclusion SGC from newborn rats strongly expresses PMCA2 and different splice variants are present at PMCA2 splice site A and C. Key words: Spiral ganglion; Plasma membrane calcium-transporting ATPases; Rats