Improved resuscitation after cardiac arrest in rats expressing the baculovirus caspase inhibitor protein p35 in central neurons.
BACKGROUND
Global cerebral ischemia is associated with delayed neuronal death. Given the role of caspases in apoptosis, caspase inhibitors may provide neuronal protection after cardiac arrest. To this end, the authors generated a transgenic rat line expressing baculovirus p35, a broad-spectrum caspase inhibitor, in central neurons. Its effects were evaluated on neuronal cell death and outcome after global cerebral ischemia.


METHODS
Global cerebral ischemia was induced by cardiocirculatory arrest. After 6 min, animals were resuscitated by controlled ventilation, extrathoracic cardiac massage, epinephrine, and electrical countershocks. Neuronal death was assessed after 7 days by histologic evaluation of the hippocampal cornu ammonis 1 sector. Postischemic outcome was assessed by determination of overall survival and according to neurologic deficit scores 24 h, 3 days, and 7 days after resuscitation.


RESULTS
The rate of 7-day survival after cardiac arrest for the transgenic rats (85%) was significantly higher than that for the nontransgenic controls (52%; P < 0.05). However, no differences were observed either in the number of terminal deoxynucleotidyltransferase-mediated d-uracil triphosphate-biotin nick end-labeling-positive cells or viable neurons in the cornu ammonis 1 sector or in the neurologic deficit score when comparing surviving transgenic and nontransgenic rats. These findings suggest that neuronal apoptosis after cardiac arrest is not primarily initiated by activation of caspases.


CONCLUSIONS
Expression of baculovirus p35 can improve survival after cardiac arrest in rats, but the mode and site of action remain to be elucidated.
Vogel
Peter
P
Department of Anesthesiology, University of Heidelberg, Germany.
Putten
Herman v d
Hv
Popp
Erik
E
Krumnikl
Jakub J
JJ
Teschendorf
Peter
P
Galmbacher
Roland
R
Kisielow
Malgorzata
M
Wiessner
Christoph
C
Schmitz
Albert
A
Tomaselli
Kevin J
KJ
Schmitz
Bernd
B
Martin
Eike
E
Böttiger
Bernd W
BW
D000818:Animals; D030801:Animals, Genetically Modified; D016367:Baculoviridae / Q000378:metabolism*; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D001923:Brain Chemistry / Q000235:genetics; D002545:Brain Ischemia / Q000473:pathology; D016887:Cardiopulmonary Resuscitation; D061945:Caspase Inhibitors; D016923:Cell Death / Q000502:physiology; D004597:Electroshock; D004791:Enzyme Inhibitors / Q000378:metabolism*; D006323:Heart Arrest / Q000503:physiopathology*; D006624:Hippocampus / Q000473:pathology; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D051034:Inhibitor of Apoptosis Proteins; D008845:Microinjections; D009422:Nervous System Diseases / Q000209:etiology / Q000235:genetics / Q000473:pathology; D009474:Neurons / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013534:Survival; D014764:Viral Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*
D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D051034:Inhibitor of Apoptosis Proteins; D014764:Viral Proteins; C086430:inhibitor of apoptosis, Nucleopolyhedrovirus