title: Enzyme response of traumatized tissue after intracortical injection into 5 day old rat brain.
abstract: Penetration of a microneedle and injection of 4 μl. saline into the neocortex of the 5 day old rat brain produced no changes in behaviour of the rats up to 21 days post-injection. Within 24 hours sections indicated that tissue damage was apparent only at the pia-arachnoid membrane and where fluid was released; elsewhere the needle pathway was identified by the enzyme response. The enzyme histochemistry showed a marked increase in glial cell activity of some phosphatases within 24 hours at the site of injury; the pia-arachnoid and outer limiting membrane also showed abnormally high phosphatase reactions. NADH(2)-diaphorase was the only dehydrogenase that was raised in some nerve and glial cells at 24 hours post-injection but other dehydrogenases, mainly LDH and SDH, showed changes at four days post-injection. The phosphatases and 5'-nucleotidase previously showing intense glial cell enzyme reactions appeared to reach peaks of activity at eight days, and at 16 days the onset of scarring was apparent. In the pia-arachnoid enzyme activity increased to 21 days. Some enzymes, particularly AChE and MAO, showed no alterations of note throughout.
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000135:Acid Phosphatase / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001099:Arachnoid / Q000201:enzymology; D001930:Brain Injuries / Q000201:enzymology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008995:Monoamine Oxidase / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009708:Nucleotidases / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D010841:Pia Mater / Q000201:enzymology; D011755:Pyrophosphatases / Q000378:metabolism; D051381:Rats; D012965:Sodium Chloride / Q000494:pharmacology; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013831:Thiamine / Q000378:metabolism; D013997:Time Factors
chemical_list: D012965:Sodium Chloride; D010088:Oxidoreductases; D005993:Glycerolphosphate Dehydrogenase; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D013385:Succinate Dehydrogenase; D008995:Monoamine Oxidase; D009247:NADH, NADPH Oxidoreductases; D008058:Dihydrolipoamide Dehydrogenase; D000110:Acetylcholinesterase; D009708:Nucleotidases; D000135:Acid Phosphatase; D010744:Phosphoric Monoester Hydrolases; D000251:Adenosine Triphosphatases; D011755:Pyrophosphatases; D008274:Magnesium; D013831:Thiamine