Neurotoxic effects of gibberellic acid (GA3) and its withdrawal in adult male albino rats: a light and electron microscopic study

Abstract

The present investigation aims to illustrate the effects of gibberellic acid (GA3) on the histology and ultrastructure of the cerebellum of rats as well as the possibility of recovery after GA3 withdrawal. Rats were equally divided into five groups. Group I served as control. Groups II & III received GA3 daily in drinking water in two gradually increasing doses of 100 and 200 ppm, respectively, for 8 weeks. Groups IV & V received the same treatment of GA3 as the second and third groups then were left without any treatment for another 8 weeks. Light microscopic examination of the cerebellar cortex of GA3-treated animals revealed its prominent neurotoxic effect on Purkinje cells and granular nerve cells in association with vacuolation in the molecular layer. Ultrastructure of the cerebellum of GA3-treated rats confirmed the light microscopic observations. The previous changes were more severe in rats treated with 200 ppm GA3. However, stoppage of GA3 administration for 8 weeks has resulted in some sort of regression of the previously mentioned effects. In conclusion: results of the current study suggested that the toxic effects of GA3 were dose-dependent. While, after GA3 stoppage, 8 weeks period of follow up showed incomplete recovery of these toxic effects. So, gibberellic acid should be used cautionary.