CCL2 and hypertensive disorder: Furthermore, studies in models of both primary and secondary hypertension reveal upregulation of CCL2 both peripherally and centrally (Sriramula et al., 2013; Li et al., 2014; Song et al., 2014), with a 3-fold elevation in the levels of CCL2 within the PVN of hypertensive animals (Sriramula et al., 2013; Li et al., 2014; Song et al., 2014).