Inflammatory Cell Infiltration and Expression of AT1 and AT2 Receptors in Angiotensin II and High-Salt Diet-Induced Balb/CJ Mice

Abstract: Pulmonary oedema and pulmonary hypertension are often associated with heart failure. The Balb/CJ and C57BL/6J mouse strains have been shown to exhibit distinct genetic susceptibilities to heart failure. Balb/CJ develops reduced heart function associated with pulmonary edema and pulmonary hypertension when treated with angiotensin II and a high-salt diet (ANG II + Salt) while C57BL/6J does not. The aim of this study was to investigate the effects of ANG II + Salt on lung damage by studying the potential immune cell infiltration in Balb/CJ mice and to determine whether differences in expression levels of angiotensin II type 1 and 2 (AT1 and AT2) receptors contribute to these effects. Protein expression of macrophages, neutrophils, AT1 receptors, and AT2 receptors in lung samples from six Balb/CJ mice and seven C57BL/6J mice treated with ANG II + Salt were analysed using Western blot. Five untreated mice from each strain were used as controls. The results indicated a significant difference (p=0.009) in the expression of macrophages between Balb/CJ mice treated with ANG II + Salt with a mean value of 17.30 and C57BL/6J mice treated with ANG II + Salt with a mean value of 9.34. No significant differences were observed in the expression of neutrophils, AT1 receptors, or AT2 receptors between the groups. Contrary to our expectations, the results did not support immune cell infiltration in Balb/CJ mice lungs or show higher AT1 receptor levels in Balb/CJ mice compared to C57BL/6J mice. Further research is required to understand the underlying mechanisms involved.