[The effect of a synthetic tripeptide nervous tissue cultured in vitro]

Explants from chick embryo PNS (ganglion trigeminale) and from CNS of embryonal rats (hippocampus) and dissociated cells from chick embryo cerebral hemispheres were cultivated in maximow chambers in the presence of various concentrations of placental serum and of a chemically synthesized tripeptide Gly-His-Lys. 1. The presence of tripeptide in the nutrient medium with a low concentration of serum did not compensate the outgrowth of nerve fibers, that take place in the growth medium. 2. In the presence of tripeptide in the nutrient medium with low concentration of serum the index of growth area increased significantly. 3. Within the first days in cell cultures 0,01 microgram tripeptide pro ml medium stimulated the outgrowth of neuronal processes. 4. The experiments indicated, that the tripeptide did not replace the serum. The possible role of tripeptide as a system in controlling neuron-glial ratio in vitro is discussed.