Effects of focal cerebral ischemia on inositol 1,4,5-trisphosphate 3-kinase and 5-phosphatase activities in rat cortex.

Abstract

Ins(1,4,5)P3 3-kinase and 5-phosphatase are important enzymes responsible for the metabolism of Ins(1,4,5)P3, a second messenger for mobilization of intracellular Ca2+ stores. Focal cerebral ischemia induced in Long Evans rats through occlusion of the right middle cerebral artery (MCA) and both common carotid arteries resulted in a time-dependent decrease in the 3-kinase activity but not the 5-phosphatase activity. Approximately 50% of the 3-kinase activity in the cerebral cortex of the right MCA territory disappeared after 60 min of ischemia, and the enzyme activity was not restored during reperfusion. Reperfusion for 24 hr after a 60 min ischemic insult almost abolished the 3-kinase activity but the 5-phosphatase activity remained unaltered. These results suggest that the Ins(1,4,5)P3 3-kinase is one of the target enzymes of cerebral ischemia. The changes in Ins(1,4,5)P3 metabolism may be associated with the changes in intracellular Ca2+ homeostasis that underlies the pathophysiology of neuronal cell death.

• Authors: T A Lin, T N Lin, Y Y He, C Y Hsu, G Y Sun
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 184 Issue 2 Pg. 871-7 (Apr 30 1992) ISSN: 0006-291X [Print] United States
• PMID: 1315536 (Publication Type: Journal Article)

Chemical References

• Phosphotransferases
• Phosphotransferases (Alcohol Group Acceptor)
• Inositol 1,4,5-trisphosphate 3-kinase
• Phosphoric Monoester Hydrolases
• Inositol Polyphosphate 5-Phosphatases

Topics

• Animals
• Cerebral Cortex (enzymology)
• Functional Laterality
• Inositol Polyphosphate 5-Phosphatases
• Ischemic Attack, Transient (enzymology)
• Kinetics
• Phosphoric Monoester Hydrolases (metabolism)
• Phosphotransferases (metabolism)
• Phosphotransferases (Alcohol Group Acceptor)
• Rats
• Reperfusion
• Time Factors