Nuclear-envelope nucleoside triphosphatase kinetics and mRNA transport following brain ischemia and reperfusion.

Abstract

STUDY HYPOTHESIS:

We attempted to determine whether the reduced egress of mRNA from brain nuclei following in vivo ischemia and reperfusion is caused by direct damage to the nuclear pore-associated NTPase that impairs the system for nuclear export of polyadenylated, or poly(A)+, mRNA.

DESIGN:

Prospective animal study.

INTERVENTIONS:

NTPase activity and poly(A)+ mRNA transport were studied in nuclear envelope vesicles (NEVs) prepared from canine parietal cortex isolated after 20 minutes of ischemia or 20 minutes of ischemia and 2 or 6 hours of reperfusion.

RESULTS:

Brain NEV NTPase Michaelis-Menten constant (Km) and maximum uptake velocity (Vmax) and the ATP-stimulated poly(A)+ mRNA egress rates were not significantly affected by ischemia and reperfusion. In vitro exposure of the NEVs to the OH. radical-generating system completely abolished NTPase activity.

CONCLUSION:

We conclude that brain ischemia and reperfusion do not induce direct inhibition of nucleocytoplasmic transport of poly(A)+ mRNA. This suggests that the nuclear membrane is not exposed to significant concentrations of OH. radical during reperfusion.

• Authors: B R Tiffany, B C White, G S Krause
• Journal: Annals of emergency medicine (Ann Emerg Med) Vol. 25 Issue 6 Pg. 809-17 (Jun 1995) ISSN: 0196-0644 [Print] United States
• PMID: 7755206 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)

Chemical References

• RNA, Messenger
• Hydroxyl Radical
• Acid Anhydride Hydrolases
• Nucleoside-Triphosphatase

Topics

• Acid Anhydride Hydrolases (pharmacokinetics)
• Animals
• Biological Transport
• Brain Ischemia (metabolism)
• Dogs
• Heart Arrest (metabolism)
• Hydroxyl Radical (metabolism)
• Nuclear Envelope (metabolism)
• Nucleoside-Triphosphatase
• Prospective Studies
• RNA, Messenger (metabolism)
• Reperfusion