Trophic influences of human and rat amniotic fluid on neural tube-derived rat fetal cells

Abstract

Normal human (week 17–20) and rat (E16–17) amniotic fluids were used as culture media for primary cultures of rat fetal (E 16) cortical, mesencephalic and striatal cell dissociates, or astroglial subcultures from the same brain regions. Phase-bright and dark cells were identified under phase contrast microscopy and their cell processes were measured utilizing semi-automated procedures. Subcultured astroglia were immuno-reacted against glial fibrillary acidic protein and fibronectin. Rat and human amniotic fluid allowed survival and growth of neuronal and non-neuronal cells. Human amniotic fluid samples were trophic in variable degrees. Cerebral cortex subcultured astroglia usually expressed a radial-like morphotype. Although charcoal-adsorbed human amniotic fluid was trophic for primary cultures, its ability to sustain neuritic growth depended on its degree of trophism before treatment. Growth of cell processes in neuronal- and glial-like cells in primary cultures was inhibited to different degrees by the addition of antisera towards nerve or epidermal growth factors. It is concluded that amniotic fluid constitutes a trophic medium for astroglia and neurons. Both, nerve and epidermal growth factors appear to be necessary for growth of cell processes in neuronal and glial primary cultures in amniotic fluid. Trophic effect of amniotic fluid on subcultured astroglia did not seem to be diminished by nerve growth factor antiserum. The role of amniotic fluid during the early phases of brain organogenesis is discussed.