Cigarette smoking decreases neurotrophin-3 expression in rat hippocampus after transient forebrain ischemia.
Stroke is a common cause of death and severe disability among adults in developed countries. Cigarette smoking adversely affects human health in many ways and is considered to be a risk factor for a stroke. However, the mechanism that determines the relative importance of neurotrophins in this process remains unclear. To study the effect of chronic cigarette smoking on ischemic stroke, in situ hybridization and immunohistochemistry were employed to detect the mRNA and protein expression of neurotrophin-3 (NT-3), respectively, which is thought to play a critical role in protection against neuronal death in brain ischemia. Rats, with or without chronic cigarette smoking, were subjected to 20 min of transient forebrain ischemia. Distribution and quantification of mRNA and protein of NT-3 in the whole hippocampus and the cell death in the hippocampal CA1-CA3 regions were determined in these rats. Experimental results show that chronic cigarette smoking produces a significantly delay and persistent down-regulation of ischemia-induced NT-3 mRNA and protein changes at 6-24h post-ischemia, and seemingly increases neuron death 7 days after reperfusion. These experimental results indicate that by influencing NT-3 expression, directly or indirectly, chronic cigarette smoking has a potentially harmful effect when acute brain ischemia attacks.
Yang
Jen-Tsung
JT
Department of Neurosurgery, Chang Gung Memorial Hospital, Chia-Yi, and College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
Chang
Chen-Nen
CN
Wu
June Hsieh
JH
Chung
Chiu-Yen
CY
Weng
Hsu-Huei
HH
Cheng
Wan-Chun
WC
Lee
Tsong-Hai
TH
D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D002546:Ischemic Attack, Transient / Q000473:pathology*; D008297:Male; D020933:Neurotrophin 3 / Q000235:genetics / Q000378:metabolism*; D009538:Nicotine / Q000008:administration & dosage; D018722:Nicotinic Agonists / Q000008:administration & dosage; D016548:Prosencephalon / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012907:Smoking; D013997:Time Factors
D020933:Neurotrophin 3; D018722:Nicotinic Agonists; D012333:RNA, Messenger; D009538:Nicotine