Changes Of Mitochondrial Ultramicrostrcture And Function Before And After Pentetrazole Kindling In The Rat's Hippocampus

Object To observe the changes of mitochondrial ultramicrostrcture and function in the rat's hippocampus befor and after pentetrazole(PTZ) induced seizures successfully and to investigate the role of mitochondrial disfunction in epileptogenisis.Methods 60 healthy male Sprague-Dawley rats were divided randomly into control and PTZ treated groups.The latter were intraperitoneally injected PTZ(30mg/kg) every 24 hours.The control groups received 0.9% saline injections instead of PTZ at the same time .Seizure manifestations were evaluated according to Racine and EEGWhen they reached each standard(Igrade,IIIgrade,kindled,after kindled 24 hours and after kindled 72 hours),they would be used to observe the mitochondrial ultramicrostrcture and to detect its' functions respectively.Results1. Animal modelAn initial subconvulsive dose of PTZ(30mg/kg) did not elicit a motor response.Subsequent injection with the same dose induced convulsive response of gradually increasing severity.Each group need time as follows: Igrade was 7.4±1.7days, IIIgrade was 17.0±6.9days,kindled was 25.1±5.9days,after kindled 24 hours was 27.0±5.4days,after kindled 72 hours was 28.1±5.5days.96.7% animals reached each standard successfully.Epileptic form discharges were found in each PTZ group.All the kindled rats had spontaneous seizures while the control group had neither seizures nor abnormal discharges on the EEG.2. The changes of mitochondrial ultramicrostrctureWe could observe that the mitochondria of the control were integrity. The mitochondrial cristae swelled in group Igrade and IIIgrade.The three kindled groups had diverse mitochondria ,such as: swelling,broken, pyknosis and vacuolization.3. The results of the detect of mitochondrial functionThe integrity of mitochondrial out membrane and the activity of COX were decreased significantly(P<0.05).Between the PTZ treaed groups ,there were significant differences except groups of the kinded and the after kindled 24 hours.Conclusions1.The changes in mitochondrial ultramicrostructure is an early pathologic phenomenon in epileptogenisis.2.Mitochondrial disfunctions contribute to epileptogenisis and damages afer seizure.