Effects of arginine vasopressin on subunit phosphorylation of GABAA receptors in rat preoptic area

AIM: To investigate the effects of arginine vasopressin (AVP) on the expression and phosphorylation of γ-aminobutyric acid (GABA) subtype A receptor (GABA_A receptor) subunits in the preoptic area (POA) of rats. METHODS: The rats were divided into AVP group (n=10), AVP+V1a receptor blocker group (n=10), V1a receptor blocker group (n=10) and control group (n=10). After intraperitoneal injection of AVP or V1a receptor antagonist for 0.5 h, the changes of the expression and phosphorylation of POA GABA_A receptor subunits (α, β and γ2) were analyzed by RT-qPCR and Western blot. RESULTS: Compared with control group, no significant change of GABA_A receptor subunit expression in the rats injected with AVP or V1a receptor antagonist was observed. AVP up-regulated the phosphorylation level of POA GABA_A receptor γ2 subunit (P<0.05), and significantly increased the expression and phosphorylation of protein kinase C (PKC) and calcium/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ). CONCLUSION: Exogenous AVP has no effect on expression of POA GABA_A receptor subunits (α, β and γ2) and is involved in modulation of GABAergic synaptic transmission in the POA by activation of PKC and CaMKⅡ and phosphorylation of γ2 subunit via V1a receptor.