Premium
Induction by Hydrocortisone of Glutamine Synthetase in Mouse Primary Astrocyte Cultures
Author(s) -
Juurlink B. H. J.,
Schousboe A.,
Jørgensen O. S.,
Hertz L.
Publication year - 1981
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1981.tb02388.x
Subject(s) - glutamine synthetase , hydrocortisone , astrocyte , glutamine , biology , medicine , cell culture , endocrinology , microgram , microbiology and biotechnology , in vitro , biochemistry , amino acid , central nervous system , genetics
Glutaminc synthetase activity was investigated in developing primary astroglial cultures established from newborn mouse cerebral hemispheres. Between the 2nd and 4th week of culture there was little change in activity under our standard culturing conditions; however, when hydrocortiwne (10 μM) was added to the cultures for 48 h, the enzyme activity increased two‐ to fourfold, depending upon the age of the culture, with maximum response in 2‐week‐old cultures. The addition of dibutyryl cyclic AMP (dRcAMP) to the culture medium caused morphological differentiation of the astroglial cells but eliminated the response of the cells to hydrocortisone. Culturing in elevated serum levels, which delays morphological differentiation and inhibits astroglial cytodifferentiation after exposure to dBcAMP, shifted the time of maximal response to hydrocortisone from 2 to 3 weeks and prevented the abolishment of glutamine synthetase induction by dBcAMP. The induction of glutamine synthetase by hydrocortisone was prevented by actinomycin D (0.5 μg/ml), indicating its dependence upon RNA and protein synthesis. The present work thus confirms reports in the literature that hydrocortisone induces glutamine synthetase in neural tissues, but differs from the findings of Moscona and co‐workers in the chick retina that intact tissues are required for the induction to occur.