New perspectives on angiotensin-converting enzyme 2 and its related diseases

Table 1 List of animal studies on the high-sodium diet and angiotensin-converting enzyme 2

Animal	Study details	Main findings	Ref.
Zucker rats	Lean and obese Zucker rats were fed a normal-sodium diet (0.4%) or a high-sodium diet (8%) for 2 wk	ACE2 mRNA and protein expression was significantly reduced in HS-fed obese Zucker rats	Samuel et al[19]
Wistar rats	Rats were fed three salt concentrations (0.2%, 1.2%, 8.2%) for 4 wk after uninephrectomy of the left kidney	HS diet increased the glomerular ACE/ACE2 ratio	Bernardi et al[20]
Wistar rats	After 4 wk of induction of hypertension (2-kidney 1-clip model), rats were fed a normal-sodium diet (0.4%) or a high-sodium diet (8%) for 2 wk	HS diet decreased urinary angiotensinogen, ACE, and ACE2 expression in the clipped and unclipped kidneys	Shimoura et al[21]
SHR	Rats were fed three NaCl content diets (0.03%, 0.3%, 3%) for 6 mo	HS diet decreased ACE2 protein expression in kidney tissues	Berger et al[18]
SHR	Rats were fed an 8% salt diet for 5 wk	HS diet decreased cardiac ACE2 mRNA and protein levels	Varagic et al[22]
DS and DR rats	DS and DR rats were fed low-sodium chow (0.45%) or high-sodium chow (7%) for 8 wk and treated with or without eplerenone (100 mg/kg/d), candesartan (10 mg/kg/d), or both drugs for 8 wk	HS diet increased angiotensinogen mRNA and decreased ACE2 mRNA in the hearts of DS rats; candesartan increased ACE2 mRNA levels in the heart	Takeda et al[23]
SD rats	Rats were fed an 8% NaCl high-salt or 0.4% NaCl (normal-salt) diet for 3 wk, with or without antioxidant supplementation with tempol	HS diet decreased ACE2 expression; tempol reversed the imbalance of renal RAS components (decrease in Ang II and AT1R and increase in AT2, ACE2, Ang 1-7, and MasR staining intensity)	Cao et al[24]

SHR: Spontaneously hypertensive rats; DS rats: Dahl salt-sensitive hypertensive rats; DR rats: Dahl salt-resistant rats; SD rats: Sprague-Dawley rats; HS: High-sodium; ACE2: Angiotensin-converting enzyme 2; MasR: Mas receptor; AT1R: Angiotensin type 1 receptor; AT2: Angiotensin type 2; Ang 1-7: Angiotensin 1-7; RAS: Renin angiotensin system.