Effects of ghrelin on seizures in rats and expression of the gamma-aminobutyric acid

Abstract

Objective To explore the effects of ghrelin on hippocampal neurons after seizures induced by kainic acid (KA),and to investigate the correlation between Ghrelin and the expression changes in hippocampal gamma-aminobutyric acid (GABA) in rats.Methods A model of KA-induced epilepsy in rats was established,and intervened with exogenous ghrelin.Ethological and morphological changes were observed.Hematoxylin and eosin (HE) staining and Nissl staining were used to examine the antiepileptic effects.Immunofluorescence was used to detect the expression of GABA.Results After KA injection,the rats began to seizure after a latent period.The latency time in Ghrelin treatment group ( 12.3 ± 3.5 ) min was lengthened significantly as compared with epilepsy group [ ( 8.7 ± 1.2) min,P ＜ 0.05 ].Moreover,tonic-clonic duration in Ghrelin treatment group ( 10.8 ± 1.4) min was significantly shorter than in epilepsy group ( 15.2 ± 2.7 ) min,P ＜ 0.05 ].There was an obviously morphological changes in hippocampal neurons of epileptic rats with severe neurons loss,and statistical analysis revealed that the nerve cell apoptosis and loss in Ghrelin treatment group were decreased as compared with epilepsy group at different time points (P ＜ 0.05).Immunofluorescence indicated that the number of GABA neurons was continued to decrease with time as compared with control group after injection of KA into the rat hippocampus within 24 h.And its decrease trend was more gentle after injecting Ghrelin ( P ＜ 0.05 ).Conclusion Our results implied that Ghrelin had protective effects on hippocampal neurons by influencing the expression of GABA in central nervous system. Key words: Ghrelin; Epilepsy; Gamma-aminobutyric acid; Kainic acid