Two dissimilar AT1 agonists distinctively activate AT1 receptors located on the luminal membrane of coronary endothelium

Ang II effects are transient due to desensitization and cause tachyphylaxis to Ang II and toward Ang II-POL suggesting that both Ang II and Ang II-POL act on the same receptor group. In contrast, Ang II-POL effects are sustained and do not cause tachyphylaxis. The results show that intravascular Ang II and Ang II-POL act differentially by an unknown mechanism on CELM's AT1R and suggest that intravascular Ang II and Ang II-POL cause PIE and CCP by activation limited to CELM's AT1R through an unknown mechanism that is space-confined to the CELM's AT1R.