title: Glutamine synthetase induction in chick embryo retina monolayers.
abstract: Induction of glutamine synthetase (GS) by cortisol has been shown to occur in monolayer cultures of cells obtained by enzymatic dissociation of retinas from 8- and 12-day-old chick embryos with papain (0.1%) or trypsin (0.25%). Although essentially single cells when plated, monolayers obtained by enzymatic dissociation show significant aggregation by 4--6 h. Monolayers prepared by mechanical dispersion (cells forced through successively smaller gage needles) are minimally inducible, perhaps owing to poor viability in such cultures. Storage at 4 degrees C for 24 h prior to treatment with cortisol significantly elevated both basal GS activity and inducibility in whole (but not in monolayer) retina cultures.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D003080:Cold Temperature; D004790:Enzyme Induction; D005974:Glutamate-Ammonia Ligase / Q000096:biosynthesis*; D006854:Hydrocortisone / Q000494:pharmacology; D010206:Papain / Q000378:metabolism; D012160:Retina / Q000201:enzymology*; D014357:Trypsin / Q000378:metabolism
chemical_list: D014357:Trypsin; D010206:Papain; D005974:Glutamate-Ammonia Ligase; D006854:Hydrocortisone