The ultrastructural changes of the wall of the fourth ventricular foramina following intraventricular autogenous blood infusion present four meaningful findings for the patho-genesis of secondary hydrocephalus. Using the transmission and scanning electron microscopy (TEM and SEM), it has found that minimal to marked separation of the intercellular cleft coincided with the intra-and intercellular vacuolation and swelling of the glial fibers in the subependymal glial sheath by the 7th day of blood infusion. A f1attening of the contours of the ependymal cells and their nuclei was noted under the TEM and a seperation of ependymal cells was pronounced under the SEM during the period between the 28th and 42nd day. Ultrastructural changes of the ependymal cells correlated with the time factor and not with the blood volume infused. The supraependymal cells (SEC) seen on the ventricular surface were indicative of neuron-like structure rather than macrophages.
Animal ; Blood Transfusion* ; Cats ; Cerebral Ventricles/ultrastructure* ; Comparative Study ; Female ; Hydrocephalus/pathology ; Male ; Microscopy, Electron ; Microscopy, Electron, Scanning

To detect the function and expression of ventricular M3 receptor (M3R) in cerebral-cardiac syndrome (CCS) model rats and to explore the relationship between the expression of M3R and the arrhythmia resulted from CCS, CCS model rats were induced by occluding right middle cerebral artery. ECG was monitored. Intracellular calcium ([Ca2+]i) changes after agitating M3R were recorded by laser scanning confocal microscope. Changes of M3R expression in the ventricular tissue were detected by Western blotting. QRS and QT intervals in CCS group were remarkably longer than that in sham group. According to the results of Western blotting, the level of M3R expression was remarkably lower in CCS group compared with that in the normal group. KCl induced [Ca2+]i increasing in CCS group could be depressed by choline and the effect of choline could be blocked by 4-DAMP. The lower expression of M3R in CCS group may be one of important reasons of arrhythmia resulted from CCS. M3R that depressed the [Ca2+]i increasing agitated by choline may become a new target to cure arrhythmia resulted from CCS.
Animals ; Arrhythmias, Cardiac ; etiology ; metabolism ; pathology ; physiopathology ; Calcium ; metabolism ; Choline ; pharmacology ; Electrocardiography ; Heart Ventricles ; metabolism ; Infarction, Middle Cerebral Artery ; complications ; Male ; Muscarinic Antagonists ; pharmacology ; Myocardium ; metabolism ; ultrastructure ; Myocytes, Cardiac ; metabolism ; Piperidines ; pharmacology ; Potassium Chloride ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar ; Receptor, Muscarinic M3 ; antagonists & inhibitors ; metabolism

OBJECTIVETo evaluate pathologically the effect of the single or combined application of UDP-glucose, GDNF and memantine on the improvement of white matter injury in neonatal rats with periventricular leukomalacia (PVL) under light and electron microscopy.

METHODSA five-day-old neonatal rat model for PVL was established by ligation of the lateral common carotid artery following 120-minute hypoxia. Rats were randomly divided into six groups (30 rats in each group): sham-operated, PVL, UDP-glucose (UDP-glucose 2000 mg/kg intraperitoneally after PVL), GDNF (GDNF 100 μg/kg intracerebrally after PVL), tmemantine (memantine 20 mg/kg intraperitoneally after PVL), and a combination administration of three drugs (UDP-glucose, GDNF and memantine). The rats were sacrificed 7 or 21 days after PVL for assessment of pathological changes in the white matter under both light and electron microscopy. The number and thickness of the myelin sheath in the white matter were measured under electron microscopy, and both of pathological grading and scoring were undertaken under light microscopy.

RESULTSThere was rare and sparse myelinogenesis with a loose arrangement of nerve fibers in the white matter under electron microscopy in the PVL group at 7 and 21 days after PVL. The number and thickness of the myelin sheath in the PVL group were significantly less than in the sham-operated, UDP-glucose, GDNF, memantine and combination administration groups (P<0.01). The results of pathological grading of white matter under light microscopy showed that all rats in the PVL group manifested either mild injury (38%-50%) or severe injury (50%-62%) at 7 and 21 days after PVL. The majority of rats (50%-88%) in the four drug administration groups had normal white matter at 7 and 21 days after PVL. The pathological scores at 7 and 21 days after PVL in the PVL group were the highest, and they were significantly higher than in the other five groups (P<0.05).

CONCLUSIONSThe single or combined application of UDP-glucose, GDNF and memantine may significantly improve pathological changes in the white matter of rats with PVL. The favorable effect is inferred to be closely correlated with the improvement of brain microenvironment and the enhancement of nerve regeneration promoted by the three drugs.

Animals ; Brain Ischemia ; drug therapy ; pathology ; Cerebral Ventricles ; pathology ; ultrastructure ; Female ; Glial Cell Line-Derived Neurotrophic Factor ; administration & dosage ; therapeutic use ; Humans ; Infant, Newborn ; Leukomalacia, Periventricular ; drug therapy ; Male ; Memantine ; administration & dosage ; therapeutic use ; Microscopy, Electron ; Rats ; Rats, Sprague-Dawley ; Uridine Diphosphate Glucose ; administration & dosage ; therapeutic use