Cytosolic free Ca2+ ([Ca2+]i) was measured in dissociated cerebral cells isolated from fetal rats with the fluorescent indicater fura-2. Increase in [Ca2+]i occurred rapidly following exposure of the cells to 50 mmol/L KCl, 10(-7) mol/L Bay K 8644 or 200 mumol/L glutamate (Glu). [Ca2+]i elevated by K(+)-depolarization was attenuated by pretreatment with 10(-7), 10(-6) mol/L daurisoline (Dau). The response of [Ca2+]i to K(+)-depolarization did not change when 10(-8) mol/L Dau was added. When 10(-8)-10(-6) mol/L Dau was added to the cell suspensions prior to exposure to Glu, the Glu-stimulated rises in [Ca2+]i were reduced significantly. However, Dau (10(-6), 10(-7) and 10(-8) mol/L) did not alter the response to Bay K 8644. These results indicate that Dau can inhibit the increase of [Ca2+]i in fetal rat cerebral cells induced by certain Ca2+ agonists, especially Glu, suggesting that this drug may have a protective effect against cerebral cellular injury.