[Effects of clinorotation on cytosolic free calcium level in embryonic chick brain cells]

Cytosolic free Ca2+ ([Ca2+]i) in suspended brain cells of chicken embryos hatched for 6-18 d (E6-E18) was measured by using the fura-2/AM fluorescence spectroscopy. The biological effects of microgravity on the embryonic chicks were simulated by revolving on a clinostat during their hatch. The experimental results showed that level of [Ca2+]i in E8-E17 embryonic brain cells decreased after revolving for different period. [Ca2+]i in brain cells of E10 and E13 chick embryos reduced significantly (P < 0.01) after revolving 4-7 h and 24 h respectively. When E10 and E13 chick embryos were incubated again as long as being revolved, [Ca2+]i in brain cells rose but were still lower than the controls. The levels of cytosolic free calcium in brain cells of revolved E17 embryonic chicks increased after being colorpunctured by red light. These results demonstrate that the decrease of [Ca2+]i in embryonic chick brain cells caused by clinorotation is reversible, and colorpuncture can accelerate this recovery.