Effects of adenosine-receptor excitant on genic expression of bcl-2, Bax of hippocampal cells in epileptic rats

Chunyan WU; Xiaohui PENG; Lifang MU; Hongli ZHAO; Aiqi ZHANG; Mengying HU

ABSTRACT

BACKGROUND:

Hippocampal neuron presents remarkably injury in cerebral after seizure of epilepsy. Necrosis and apoptosis are two kinds of neural cell injury after epilepsy and play an important role in neural injury of epilepsy. Being endogenous neural protective transmitter, adenosine may inhibit the release of excitatory amino acid, production of oxygenic free radical and action of nitric oxide. Simultaneously, it can improve cerebral blood flow and anti-convulsion. But it has been unknown concerning to the relationship between adenosine and cell apoptosis after epilepsy yet.

OBJECTIVE:

To observe the effects of 2-CAdo adenosine-receptor excitant on genetic expression of bcl-2, Bax of hippocampal cells in epileptic rats and further probe into the mechanism of adenosine on anti-convulsion and brain protection.

DESIGN:

Completely randomized controlled experimental research in which the experimental animals were taken as the objects.

SETTING:

Pediatrics department and general surgical department of one oil field general hospital, and pediatric internal department of a hospital affiliated to one university.MATERIALS The experiment was performed in Experimental Zoology Departnent and Pathological Teaching & Research Department of Harbin Medical University from October 2002 to March 2003. Totally 104 Wistar rats of either sex were employed, weighing varied from 200 g to 250 g. The animals were randomly divided, named as normal group 8 rats, epileptic group 32 rats, epileptic & 2-CAdo group 32 rats, and epileptic & physiological saline group 32 rats.

INTERVENTIONS:

The animal epileptic model was set up by intra-abdominal injection of coriamyrtin 15 mg/kg(provided by Pathology Department of Harbin Medical University. Convulsion presented in all of rats, 5 minutes later after injection, lasting for 1 or 2 minutes. In epileptic & 2-CAdo group, 2-CAdo(provided by ICN company), 0.6 mg/kg, was injected from the vein on the tail 1 hour before coriamyrtin injection and 1 hour after convulsion respectively. In epileptic & physiological saline group, the physiological saline of equal dosage was injected from the vein on the tail 1 hour before coriamyrtin injection and 1 hour after convulsion respectively.MAIN OUTCOME

MEASURES:

Positive cell counts of bcl-2 and Bax genetic expression in hippocampal CA1 area.

RESULTS:

Twenty-four hours after epilepsy seizure, neural cell bcl-2 expression was increased in hippocampal CA1 area, was remarkably decreased in 48 hours, and the expression was only little amount in 72 hours, but it was increased again in 7 days. Bax expression began increased in 24 hours after epilepsy seizure, was significantly increased in 48 hours, reached the peak in 72 hours, the expression was the minimum in 7 days. In epileptic & 2-CAdo group, bcl-2 expressions at corresponding times were remarkably increased compared with epileptic group and epileptic & physiological saline group( P＜ 0.05), Bax expressions were remarkably decreased compared with epileptic group and epileptic & physiological saline group( P ＜ 0.05), indicating statistical significance.

CONCLUSION:

2-CAdo can reduce apoptosis of hippoeampal neural cells after epilepsy seizure and provide a certain protection for neural cells.