Influence of AVP4-8 on MAPK activity in astrocytic glial and fetal neuronal cells in primary culture.

AIM

To study the effect of argipressin (4-8) (AVP4-8) on the mitogen-activated protein kinase (MAPK) activity in astroglial culture and fetal neuronal culture from rat cerebral cortex and hippocampus. Some protein kinases involved in this signal pathway were also addressed.

METHODS

Rat brain primary cells were cultured in serum free medium or starved for 24 h before use. Cells were transferred to Ca2+ and Mg2+ free Dulbeco's phosphate buffer (D-PBS) with various drugs. MAPK activity was measured.

RESULTS

The main findings were: (1) AVP4-8 induced the MAPK activity in rat brain astroglial culture but not in fetal neuronal cultures. And this was blocked by ZDC (C) PR, an antagonist of AVP4-8. (2) PD98059, a potent selective inhibitor of MAPK/ERK kinase (MEK) and GF109203X, a specific inhibitor of protein kinase C (PKC) abolished AVP4-8-evoked MAPK activity on astrocytes.

CONCLUSION

AVP4-8 can activate the MAPK activity in astrocytes but not in fetal neuronal culture. MEK and PKC may be involved in the AVP4-8-evoked cascade.