title: The effect of kainate on protein kinase C, GABA, and the uptake of serotonin in the rabbit retina in vivo.
abstract: The purpose of this study was to investigate the effect of kainate on protein kinase C (PKC), gamma-aminobutyrate (GABA) and serotonin uptake in the rabbit retina. Kainate when injected into the vitreous humour produces a change in the GABA immunoreactivity within 6 hours. After 3 days, remnants of the normal GABA immunoreactivity still persist and additionally astrocyte and microglia-like elements "stain" positively for GABA. After 7 days exposure to kainate none of the normal GABA immunoreactivity is apparent, instead a number of round-shaped elements which may be reactive astrocytes and/or microglia stain positively for GABA. During these stages kainate does not affect the alpha PKC immunoreactivity associated with the on-bipolar cells. Six hours following kainate treatment the ability of certain GABA amacrine cells to take up exogenous serotonin is unaffected. After three days only a few of these cells can still take up exogenous serotonin and then not avidly. After seven days the GABA/serotonin amacrine cells cannot take up exogenous serotonin suggesting that all of these neurons are irreversibly damaged. One hour after treatment with kainate both calcium-dependent and -independent PKC species are translocated from the cytosolic to membrane compartments. After 5 hours and 7 days there was also evidence from the enzyme assay experiments that kainate caused the calcium-dependent and -independent PKC enzymes to be translocated but because the total enzyme activity was reduced due perhaps to down-regulation of the enzyme this was difficult to assess precisely.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Nuffield Laboratory of Ophthalmology, Oxford University, U.K.
authors.forename: N N
authors.initials: NN
authors.lastname: Osborne
authors.forename: R J
authors.initials: RJ
authors.lastname: McCord
authors.forename: J
authors.initials: J
authors.lastname: Wood
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism; D007608:Kainic Acid / Q000494:pharmacology*; D007700:Kinetics; D011493:Protein Kinase C / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors; D014822:Vitreous Body / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D012701:Serotonin; D005680:gamma-Aminobutyric Acid; D011493:Protein Kinase C; D007608:Kainic Acid