Influence of AVP(4-8) on MAPK activity in astrocytic glial and fetal neuronal cells in primary culture

AIM: To study the effect of argipressin (4 - 8) (AVP(4-8)) on the mitogen-a ctivated protein kinase (MAPK) activity in astroglial culture and fetal neu ronal culture from I-at cerebral cortex and hippocampus. Some protein kinas es 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+ flee Dulbeco's phosphate buff er (D-PBS) with various drugs. MAPK activity was measured. RESULTS: The mai n findings were: (1) AVP(4-8) induced the MAPK activity in rat brain astrog lial culture but not in fetal neuronal cultures. And this was blocked by ZD C (C) PR, an antagonist of AVP(4-8). (2) PD98059, a potent selective inhibi tor of MAPK/ERK kinase (MEK) and GF109203X, a specific inhibitor of protein kinase C (PKC) abolished AVP(4-8)-evoked MAPK activity on astrocytes. CONC LUSION: AVP(4-8) can activate the MAPK activity in astrocytes but not in fe tal neuronal culture. MEK and PKC may be involved in the AVP(4-8)-evoked ca scade.