Abstract:

Objective To investigate differential distribution and gene content of two isoforms of Na⁺-K⁺-2Cl^- co-transporter(NKCC), NKCC1 and NKCC2 in rat gastric mucosa.
Methods Immunofluorescence and realtime PCR were used to investigate the distribution and expression of NKCC1 and NKCC2 in different parts of stomach(gastric fundus, corpus and antrum).
Results ① NKCC1 immunoactivity in the gastric mucosa was found in the bottom part of gastric fundus and antrum, and middle and bottom mucosa of gastric corpus of rats, and cell membrane showed strong NKCC1 labeling. NKCC2 distributed across the full-thickness mucosa of gastric corpus and antrum but in the upper 1/3 mucosa of gastric fundus of rat, and it was dispersed in the cytoplasm and cell membrane. ② Real-time PCR indicated that the mRNA of NKCC1 expressed mostly in the gastric corpus, however, the mRNA of NKCC2 expressed mostly in the gastric antrum.
Conclusion In normal rats, the two isoforms of NKCC showed differential distribution and mRNA expression in the gastric mucosa; NKCC1 distributed mostly in the bottom or middle and bottom part of gastric mucosa, NKCC2 distributed mostly in the upper or full-thickness of gastric mucosa.

Key words: Na⁺-K⁺-2Cl^- co-transporter, immunofluorescence histochemistry, real-time quantitative PCR, gastric mucosa