ActivinAisakindofpre-inflammatoryfactorthatbelongstothetransforminggrowthfactor-β(TGF-β)superfamily.ToinvestigatetheeffectandmechanismofactivinAontheactivitiesofmousemacrophages,thesecretionofNOinthesupernatantofculturedmouseperitonealmacrophageswasexaminedbyNOassaykit,andtheexpressionofiNOS,ActRIIAandARIP2mRNAinmouseperitonealmacrophageswasanalyzedbyRT-PCR.TheresultsshowedthatactivinAstimulatedthesecretionofNOandtheexpressionofiNOSmRNAinnon-activatedmousemacrophagesinatime-anddose-dependentmanner.Incontrast,activinAinthesameconcentrationinhibitedthesecretionofNOinLPS-activatedmousemacrophagesinadose-dependentmanner.ActRIIAwashighlyexpressedonmacrophages,andactivinAupregulatedtheActRIIAmRNAexpressioninmacrophages.Anti-ActRIIAantibodycanblockthesecretionofNOfromthemacrophagesstimulatedbyactivinA.Furthermore,RT-PCRanalysisrevealedthatactivinAenhancedtheARIP2mRNAexpressioninmacrophages.TheseresultsindicatedthatActivinAmaybeaweakactivatorcomparedwithLPStomousemacrophages,andactivinAmaymodulatethesecretionofNOthroughActRIIA-ARIP2signalpathwayinmousemacrophages.
