ABSTRACT
Objective:To investigate the expression of activin A in paraventricular nucleus (PVN)of the WKY rats and its influence in arterial blood pressure,and to clarify the mechanism of activin A in the regulation of arterial blood pressure by PVN.Methods:The WKY rats were selected.The expressions of activin A,ActRⅡA,ActRⅡB,and Smads mRNA in PVN of the WKY rats were measured by RT-PCR.The expression of ActRⅡA protein in PVN was detected by immunohistochemical staining.The microinjection of exogenous activin A into PVN was used to observe the changes of arterial blood pressure.The primary cultured PVN neurons from the WKY rats were divided into control group and activin A group.The mRNA expression levels of ActRⅡA,ActRⅡB,and Smads in the PVN neurons were analyzed by RT-PCR.Results:Activin A,ActRⅡA,ActRⅡB,Smad2 and Smad3 mRNA were expressed in PVN of the WKY rats.The ActRⅡ A protein expression in PVN was further confirmed by immunohistochemical staining.After microinjection of activin A or angiotensin Ⅱ (AgⅡ)into PVN,the mean arterial blood pressure was increased obviously compared with before treatment (P <0.05).Moreover,compared with control group,the expression levels of ActRⅡA and Smad3 mRNA in primary cultured PVN neurons of the rats in vitro were significantly increased (P <0.05).Conclusion:Activin A can regulate the arterial blood pressure in PVN in an autocrine or paracrine manner,which is related to ActRⅡA-Smad3 signal pathway.