title: Hyperglycemia and hypercapnia differently affect post-ischemic changes in protein kinases and protein phosphorylation in the rat cingulate cortex.
abstract: Hyperglycemia and hypercapnia aggravate intra-ischemic acidosis and subsequent brain damage. However, hyperglycemia causes more extensive post-ischemic damage than hypercapnia, particularly in the cingulate cortex. We investigated the changes in the subcellular distribution of protein kinase Cgamma (PKCgamma) and the Ca2+/calmodulin-dependent protein kinase II (CaMKII), as well as changes in protein tyrosine phosphorylation during and following 10 min normoglycemic, hyperglycemic (plasma glucose approximately 20 mM) and hypercapnic (paCO2) approximately 300 mm Hg) global cerebral ischemia. During reperfusion period, the translocation to cell membranes of PKCgamma, but not CaMKII, was prolonged by intra-ischemic hyperglycemia, while it was only marginally affected by hypercapnia. The tyrosine-phosphorylation of proteins in the synaptosomal membranes, as well as the extracellular signal-regulated kinase (ERK) in the cytosol, markedly increased during reperfusion following hyperglycemic ischemia, but to a lesser degree following hypercapnic ischemia. Our data suggest that PKCgamma, tyrosine kinase and ERK systems are involved in the process of ischemic damage in the cingulate cortex, where hyperglycemia may affect these kinases through an additional mechanism other than exaggerated acidosis.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan. jun-kuri@pharm.teikyo-u.ac.jp
authors.forename: Junichi
authors.initials: J
authors.lastname: Kurihara
authors.forename: Ken ichiro
authors.initials: Ki
authors.lastname: Katsura
authors.forename: Bo K
authors.initials: BK
authors.lastname: Siesjö
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Wieloch
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000201:enzymology*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D004586:Electrophoresis; D006179:Gyrus Cinguli; D006935:Hypercapnia / Q000201:enzymology*; D006943:Hyperglycemia / Q000201:enzymology*; D015151:Immunoblotting; D008297:Male; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism; D013574:Synaptosomes / Q000201:enzymology
chemical_list: D011494:Protein Kinases; C087857:protein kinase C gamma; D011493:Protein Kinase C; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D017027:Protein Tyrosine Phosphatases