RESUMO
Neonatal mouse astroglial cells cultured in a serum-free medium synthesize and secrete a trophic growth factor which resembles nerve growth factor (NGF). The NGF-like factor reacts with antiserum to beta subunit of NGF (beta-NGF) and, after labeling with [35S] cystine, migrates similarly to purified mouse beta-NGF in SDS polyacrylamide gel electrophoresis and Sephadex G-100 gel filtration systems. The astrocyte cell NGF-like factor displays beta-NGF-like neurite growth-promoting activity for the clonal rat pheochromocytoma (PC-12) cell line and this bioactivity is blocked by beta-NGF antiserum. These results indicate that NGF-like factor synthesized and secreted by astroglial cells, is similar, if not identical, to beta-NGF from the mouse submandibular gland and further support a potential role for NGF in the central nervous system.
Assuntos
Astrócitos/metabolismo , Fatores de Crescimento Neural/biossíntese , Animais , Animais Recém-Nascidos , Bioensaio , Células Cultivadas , Meios de Cultura , Camundongos , Fatores de Crescimento Neural/análise , Fatores de Crescimento Neural/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , RatosRESUMO
An heterologous radioreceptor assay (RRA) for nerve growth factor (NGF) has been developed to measure NGF in human umbilical cord serum. The RRA uses mouse NGF (mNGF) as iodination material and as standard and a rat pheochromocytoma clonal line of cells (PC-12) as a source of NGF receptor (KD = 3.8 X 10(-9)M). Human cord serum exhibited parallel displacement of radiolabeled NGF in the RRA. Umbilical vein and artery NGF concentrations were measured in 22 healthy, full-term infants. The mean and (SEM) umbilical vein NGF concentration (30.4 +/- 3.2 pM/ml) significantly exceeded the mean umbilical artery NGF concentration (22.4 +/- 3.3 pM/ml) (p less than 0.05). Cord serum also produced a positive bioassay response (neurite outgrowth) in PC-12 cells, and this response was inhibited by anti-hNGF antiserum. These results are compatible with placental synthesis and secretion of NGF and suggest the possibility that NGF may play a role in autonomic and perhaps central nervous system maturation in the human fetus.
