Biochemical Interactions Between Angiotensin II and Apelin in Isolated Vascular Smooth Muscle Cells

Angiotensin II, angiotensin receptors, apelins and recently de-orphanized APJ receptors are important control factors of cardiovascular system. The present studies aimed the effects of apelin-13 and [Pyr1]-apelin-13 on apoptosis of cultured rat vascular smooth muscle cells, induced by enhanced concentrations of angiotensin II, in the presence of losartan, a specific inhibitor of AT(1) angiotensin receptors type. The obtained data demonstrated that apelin-13 was less efficient in preventing the apoptosis of aortic smooth muscle cells in culture, induced by angiotensin II (in the presence of losartan), as compared to [Pyr1]-apelin-13. It could be concluded that the apoptotic effects induced by angiotensin II in rat aortic could be related to the involvement of AT(2) angiotensin receptor type, other types of receptors or pathways unrelated to angiotensin receptors. Furthermore, the apoptotic effects induced by angiotensin II are counteracted by apelins in a structure-related manner.