Astrocytes produce an insulin-like neurotrophic factor

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5022860

Kadle, R; Suksang, C; Fellows, R E

They have previously reported that survival of dissociated neurons from fetal rat telencephalon plated at low density in serum-free, hormone-free defined medium is enhanced in the presence of insulin. In the absence of insulin a similar effect on neuronal survival is observed if cells are grown in medium conditioned by glial cells. The present study was carried out to characterize the insulin-like neurotrophic activity present in the glial conditioned medium (GLCM). Conditioned medium from confluent cultures of astrogial cells maintained in a serum free defined medium without insulin was collected every two or three days. A 5 to 30kDa fraction of this medium was obtained by filtering it sequentially through YM30 and YM5 membrane filters. Binding of /sup 125/I-insulin to high density neuronal cultures was inhibited 43% by this fraction. Radioimmunoassay for insulin indicated that 1-2 ng of immuno-reactive insulin were present per ml of GLCM. Immunosequestration of the factor by insulin antibodies bound to protein A agarose gel resulted in loss of neurotrophic activity of the 5 to 30 kDa fraction. These results indicate that cultured astrocytes produce a factor immunologically and biochemically similar to insulin. This factor enhances the survival of neurons in culture and may be important for their normal development and differentiation.

• Research Organization: Univ. of Iowa College of Medicine, Iowa City
• OSTI ID: 5022860
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANTIBODIES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
FETUSES
HORMONES
IMMUNOASSAY
IMMUNOLOGY
INSULIN
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
NERVES
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
REACTION KINETICS
SURVIVAL TIME
TRACER TECHNIQUES