In DHPG-induced and 17E2 was lower than predicted if the effects of two drugs are additive. The M Possibility that the effect of DHPG k Nnte exclude include the activation of the mGlu5 S, experiments were performed in the presence of the selective mGlu5 receptor antagonists, repeated MPEP. Although small size E, the neuroprotective effect of DHPG 172 and recognized even in the presence of MPEP, and not the effect of both drugs additively. In another series of experiments, cultures were treated with 17E2 or DHPG in the presence of ER antagonist, ICI 182,780, or the selective mGlu1 receptor antagonists, JNJ treated 16,259,685. Both drugs were applied 5 min before DHPG or 17E2. As expected, treatment with ICI 182,780 abolished the activity t of protection against 17E2 A25 35 Neurotoxizit t, w During treatment with JNJ 16,259,685 abolished the neuroprotective effect of DHPG. It was unexpected, however, that the ER-receptor blockade with ICI 182,780 abolished neuroprotection, DHPG and mGlu1 receptor blockade with JNJ 16,259,685 abolished neuroprotection by 17E2. Especially with the ER interacts, because mGlu1 receptor selective ER agonist, PPT, mimicked the neuroprotective activity of t by 17E2 and its effect was of the mGlu1 receptor antagonist, JNJ blocked 16,259,685, w While the ER-selective agonist, DPN, was only slightly and its neuroprotective effect was not sensitive to JNJ 16,259,685th ER-receptor mGlu1 and converge in the activation of phosphatidylinositol 3-kinase.
Both mGlu1 and ER is known to activate PtdIns 3 K / Akt, a way that is characteristic with respect to mechanisms of neuroprotection. Therefore, the treatment creates with the inhibitor of Akt, 10 debc hydrochloride, the neuroprotective effect of DHPG and 17E2 in cortical mixed cultures with 35 A25 questioned. To investigate whether the ER and mGlu1 receptors in the activation of PtdIns 3 converge K / Akt, we used pure cultures of cortical neurons. This result allows to avoid the confusing effect Neuronal Signaling produced by stimulation of the ER in glia mixed cultures. Treatment of cultures of cortical neurons with either 17E2 or DHPG stimulated PtdIns 3 K / Akt, as detected by immunoblot analysis of phosphorylated Akt after 10 min incubation. The effect of DHPG on 17E2 and PtdIns 3 K / Akt approximately additive and the activation of ER and mGlu1 was dependent from one another again Dependent. Therefore suppresses the ER antagonist ICI 182,780, the activation of PtdIns 3 K / Akt by DHPG produced, w While the mGlu1 receptor antagonist, JNJ 16,259,685, abolished the effect of 17E2. Both ICI 182.780 and JNJ 16,259,685 were without effect on their own. The study was conducted in HEK293 cells mGlu1 receptors ER and agrees on. The cells were co-transporter expression also has a high affinity t glutamate EACC1, to limit the endogenous activation of mGlu1 receptors. Both 17E2 and potent agonist-receptor mGlu1 / 5, quisqualate, stimulated PtdIns 3 K / Akt in HEK293 cells transfected. In this particular case, however, the stimulation by the combined application of quisqualate was produced and17E2 h Higher than the observed with either drug alone. The stimulation of pAkt produced by the simultaneous administration of 17E2 and quisqualate was abolished by pretreatment with ICI 182.