Upregulation of calpain activity in neonatal rat brain after hypoxic-ischemia.
Neonatal rats were subjected to transient cerebral hypoxic-ischemia (unilateral occlusion of the common carotid artery plus 7.7% O2 for 2 h) and allowed to recover for 0 min, 30 min or 20 h. The calpain and calpastatin activities were assayed in subcellular fractions of the ipsilateral, hypoxic-ischemic and the contralateral, hypoxic hemisphere. An upregulation of calpain activity occurred in the hypoxic hemisphere, both in the major, cytosolic fraction and in the hypotonic, membrane associated fraction (110% and 133% of controls, respectively). The hypoxic-ischemic hemisphere displayed a decrease in calpain activity in the cytosolic fraction but an increase in the hypotonic fraction (90% and 111% of controls, respectively). The changes in calpastatin activity were less pronounced. This indicates that an upregulation of calpain activity occurs in parallel with development of hypoxic-ischemic damage. However, this upregulation is not necessarily coupled to development of injury as lesions are not seen in the hypoxic hemisphere.
Ostwald
K
K
Department of Anatomy and Cell Biology, University of Göteborg, Sweden.
Hagberg
H
H
Andiné
P
P
Karlsson
J O
JO
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D002534:Hypoxia, Brain / Q000201:enzymology*; D007231:Infant, Newborn; D002546:Ischemic Attack, Transient / Q000201:enzymology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology
D002135:Calcium-Binding Proteins; C033668:calpastatin; D002154:Calpain