Ischemia-reperfusion injury effects a change in expression of GnRH and its receptor in CA1 neurons in rat hippocampus.

Many researches on the change and protective effects of estrogen and its receptor in hippocampus with ischemia-reperfusion injury have been done in recent years; the study on the change of GnRH and its receptor in hippocampus with ischemia-reperfusion injury has not been seen yet. This study used immunohistochemistry and in situ hybridization method, together with an image analysis system to observe the change in expression of GnRH and its receptor in hippocampus with ischemia-reperfusion injury. The study found that the expression of GnRH and GnRH mRNA and the number of positive cells decreased with time after damage. Expression of GnRH receptor and GnRH receptor mRNA in single positive cell early increased and later decreased after injury; the number of positive cells decreased with time after injury. Three days after injury, rare GnRH, GnRHR immunoreactive positive cells and cells with GnRH mRNA, GnRHR mRNA hybridization signal could be found in the stratum pyramida of CA1 region, many cells with weak GnRH, GnRH receptor immunoreactivity and weak GnRH mRNA, GnRH receptor mRNA hybridization signal appeared at stratum oriens and stratum radiatum. These suggested that GnRH may participate in the regulation of ischemia-reperfusion injury in CA1 region and repair of brain tissue.