Apoptosis detected in the amygdala following myocardial infarction in the rat.
BACKGROUND
Myocardial infarction (MI) contains a risk factor for developing episodes of Major Depressive Disorder (MDD). Apoptosis is commonly observed in the reperfused myocardial infarcted heart, and recent findings suggest the existence of apoptosis in MDD. Cytokines, which are released by ischemic myocardium and which may induce apoptosis, have been proposed as a possible cause for MDD.


METHODS
Myocardial infarction was produced in anesthetized rats by a 40-minute occlusion of the left anterior descending coronary artery followed by 72 hours of reperfusion. Determination of apoptosis was done in the amygdala, hippocampus and vermis of MI and Sham rats treated or not with pentoxyfilline (PTX), a cytokine synthesis inhibitor (10 mg/kg/day intraperitoneal).


RESULTS
Compared to Sham rats, the amygdala of MI rats showed significantly reduced P13K activity, increased Bax/Bcl-2 ratio, caspase-3 activity, and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling)-positive cells. The effect of MI on apoptosis was completely reversed in presence of PTX. No statistical difference was observed in the hippocampus and the vermis in the different groups for any of the biochemical measurements.


CONCLUSIONS
These results indicated that MI induce apoptosis in amygdala by a cytokine-sensitive mechanism and may explain the MDD observed following myocardial infarction.
Wann
Boubacar Pasto
BP
Centre de Biomédecine, Hôpital du Sacré-Coeur, Canada.
Boucher
Matthieu
M
Kaloustian
Sevan
S
Nim
Satra
S
Godbout
Roger
R
Rousseau
Guy
G
D000679:Amygdala / Q000187:drug effects / Q000473:pathology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002531:Cerebellum / Q000187:drug effects / Q000473:pathology; D016207:Cytokines / Q000037:antagonists & inhibitors; D003865:Major Depressive Disorder / Q000473:pathology; D004195:Disease Models, Animal; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology; D020287:In Situ Nick-End Labeling; D007274:Injections, Intraperitoneal; D009203:Myocardial Infarction / Q000473:pathology*; D010431:Pentoxifylline / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values
D016207:Cytokines; D010431:Pentoxifylline