Several
ligands have been proposed for the GPR39 receptor, including the
element zinc. The relationship between GPR39 and
magnesium homeostasis has not yet been examined, nor has such a relationship in the context of
seizures/
epilepsy. We used samples from mice that were treated with an agonist of the GPR39 receptor (TC-G 1008) and underwent acute
seizures (maximal electroshock (MES)- or 6-hertz-induced
seizures) or a chronic,
pentylenetetrazole (PTZ)-induced kindling model of
epilepsy. MES
seizures and PTZ kindling, unlike 6 Hz
seizures, increased serum
magnesium concentration. In turn, Gpr39-KO mice that underwent PTZ kindling displayed decreased concentrations of this
element in serum, compared to WT mice subjected to this procedure. However, the levels of expression of TRPM7 and SlC41A1
proteins-which are responsible for
magnesium transport into and out of cells, respectively-did not differ in the hippocampus between Gpr39-KO and WT mice. Furthermore,
laser ablation inductively coupled plasma mass spectrometry applied to hippocampal slices did not reveal differences in
magnesium levels between the groups. These data show the relationship between
magnesium homeostasis and certain types of acute or chronic
seizures (MES
seizures or PTZ kindling, respectively), but do not explicitly support the role of GPR39 in mediating
magnesium balance in the hippocampus in the latter model. However, decreased expression of TRPM7 and increased expression of SLC41A1-which were observed in the hippocampi of Gpr39-KO mice treated with
TC-G 1008, in comparison to WT mice that received the same treatment-implicitly support the link between GPR39 and hippocampal
magnesium homeostasis.