RESUMO
AIM: To study the effects of Gonadotropin-releasing hormone-I (GnRH-I) analog alarenin on inositol 1, 4, 5-triphosphate (IP(3)) in gastric parietal cells of rats in vitro. METHODS: The gastric parietal cells of rats were isolated and incubated in vitro and alarenlin at various concentration were added to the medium. IP(3) was detected by radioimmunoassay. RESULTS: When alarenlin were at the concentration of 0.001, 0.01, 0.1, 1 micromol/L respectively, IP(3) was increased gradually and acted in dose-dependent way. When alarenlin was at 1 mumol/L, IP(3) reached peak-value. Meanwhile, when 1 micromol/L alarelin were incubated at different time, IP(3) acted in time-dependent way. When it was incubated for 5 min, IP(3); reached the peak value. After the cells were preincubated with phospholipase c (PLC) inhibitor (compound 48/80) for 10 min, then added 1 micromol/L alarenlin, we found that IP(3) increased slightly, and there was no difference compared with the group PLC inhibitor, which only added PLC inhibitor (P>0.05). At the same time, after the cells were preincubated with IP(3) inhibitor (heparin), then added 1 micromol/L alarenlin, IP(3) also increased mildly, and there was no difference compared with the group IP(3) inhibitor, which only added IP(3) inhibitor (P>0.05). CONCLUSION: Our data suggest that GnRH-I analog (alarenlin) could increase the content of IP(3) in gastric parietal cells of rats in vitro, and IP(3) may be an important signal molecule in the regulation of physiological function of gastric parietal cells of rats.