The effect of angiotensin 1–7 on tyrosine kinases activity in rat anterior pituitary

Angiotensin 1–7 (Ang 1–7) is a peptide originated from Ang II. It is known that in vessels Ang 1–7 shows opposite effects to Ang II. Ang 1–7 can modify processes of proliferation. However, Ang 1–7 action in pituitary gland cells was never studied. Moreover, the specific binding sites for Ang 1–7 are still unknown. The aim of this study was to examine the effects of Ang 1–7 on tyrosine kinases (PTKs) activity in the anterior pituitary. The reaction of phosphorylation was carrying out in presence of different concentration of Ang 1–7 and losartan (antagonist of AT1 receptor) and PD123319 (antagonist of AT2). Our results show that Ang 1–7 inhibited activity of PTK to 60% of basic activity. Losartan did not change the Ang 1–7-induced changes in PTKs activity. The presence of PD123319 together with Ang 1–7 caused stronger inhibition PTKs activity than Ang 1–7 alone. These observations suggest that Ang 1–7 binds to the novel, unknown, specific for this peptide receptor.