[Effects of reperfusion on neuronal changes and macrophagic response after transient focal ischemia--reperfusion of brain in rats].
Male SD rats(n = 29) were subjected to 2 hours' middle cerebral artery occlusion and were killed at various times of reperfusion (0.5-48 hours). The histological features of neuronal changes, the macrophagic response and the relationship between them were investigated. The neurons underwent acute changes(shrinking or swollen), and the pyknotic apoptotic neurons were occasionally seen within 3 hours. The number of apoptotic neurons increased with recirculation time. The scattered red neurons and ghost cells were first found at 6 hours of reperfusion. Many apoptotic neurons, apoptotic bodies were detected in the penumbra of ischemic core at 48 hours. Lectin histochemistry with GSI-B4 was performed to observe the macrophage. The results showed the active microglia and macrophage from meninges presented at 12 hours. The macrophages from parenchyma vessels appeared at 24 hours. Reactive microglia and extrinsic macrophage aggregated into the band of macrophage which phagocytized the apoptotic neurons. The results indicate that, firstly, it is important to prevent the neuronal apoptosis and reduce the volume of infarct in stroke patients; secondly, irreversible neuronal lesions simultaneously stimulate microglial activation and the presence of extrinsic macrophages from meninges was earlier than the appearance of the macrophages from parenchyma blood-monocytes. The authors also suggest that the data on the neuronal changes over time after ischemia and reperfusion be useful reference materials for selecting the most timely medication to treat cerebral infarction.
Yuan
Q
Q
Department of Anatomy, School of Basic Medical Sciences, WCUMS, Chengdu 610041.
Li
R
R
Yang
H
H
Zhang
G
G
D000818:Animals; D020244:Infarction, Middle Cerebral Artery / Q000276:immunology / Q000473:pathology*; D008264:Macrophages / Q000276:immunology* / Q000473:pathology; D008297:Male; D009474:Neurons / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology*; D013997:Time Factors