In cultured VECs and VSMCs alone ,the cAMP concentrations were both significantly increased after exogenous Ang 2 treatment and hypoxia ,and more in VECs than that in VSMCs(P<0.05).In the double-sided cellco-culture model,the difference was weakened,and the increase in cAMP concentration in VSMCs after exogenous Ang 2 treatment and hypoxia was antagonized by connexin 43(Cx43)small interfering RNA(siRNA)(P<0.05).Alexa Fluor 488-cAMP in VECs transfered into VSMCs after exoge-nous Ang2 treatment and hypoxia,which was also antagonized by Cx43siRNA(P<0.05).The cAMP antagonist inhibited the protein expression of iNOS in the VSMCs and the hyporeactivity of the VSMCs after exogenous Ang 2 treatment and hy-poxia(P<0.05).
CONCLUSION:
Ang2 may regulate the protein expression of iNOS in VSMCs and the hyporeactivity of VSMCs after hypoxia through the cAMP transfer across MEGJ.