title: Effects of enalapril on the expression of cardiac angiotensin-converting enzyme and angiotensin-converting enzyme 2 in spontaneously hypertensive rats.
abstract: BACKGROUND
  The discovery of angiotensin-converting enzyme 2 (ACE2) has greatly modified understanding of the renin-angiotensin system (RAS).
  
  
  OBJECTIVE
  To investigate the cardiac expression of ACE2 and ACE in spontaneously hypertensive rats (SHRs) and the effects of enalapril on them.
  
  
  METHODS
  Fifteen SHRs were randomly assigned to two groups: an SHR control group (n=7), treated with vehicle; and an enalapril group (n=8), treated with enalapril (15 mg/kg/day). After 4 weeks of treatment, the rats were killed and the left ventricular tissue was dissected. Reverse transcription-polymerase chain reaction and Western blot protein staining were performed to detect expression of ACE2 and ACE messenger ribonucleic acid (mRNA) and protein. Ten Wistar Kyoto rats (WKYs) served as the normotensive control group, which were treated with vehicle.
  
  
  RESULTS
  Compared with in normotensive WKYs, cardiac expression of ACE mRNA and protein in SHRs was increased (1.68±0.34 vs. 0.33±0.12, P<0.05 and 1.21±0.14 vs. 0.71±0.11, P<0.05, respectively), whereas cardiac expression of ACE2 mRNA and protein was decreased (0.50±0.15 vs. 1.16±0.24, P<0.05 and 0.71±0.24 vs. 1.22±0.14, P<0.05, respectively). After treatment with enalapril, the levels of ACE mRNA and protein were decreased (0.44±0.19 vs. 1.68±0.34, P<0.01 and 0.87±0.13 vs. 1.21±0.14, P<0.05, respectively), the level of ACE2 mRNA was increased (1.77±0.49 vs. 0.50±0.15, P<0.05) but the level of ACE2 protein remained unchanged.
  
  
  CONCLUSIONS
  In SHRs, the expression of cardiac ACE was remarkably increased, whereas ACE2 was notably decreased. Reduction of ACE and elevation of ACE2 might be one of the mechanisms underlying the antihypertensive function of enalapril.
authors.affiliation: Heart Centre, The General Hospital of Ningxia Medical University, Yinchuan, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
authors.forename: Li
authors.initials: L
authors.lastname: Cheng
authors.forename: Li-yan
authors.initials: LY
authors.lastname: Miao
authors.forename: Hong-xia
authors.initials: HX
authors.lastname: Li
authors.forename: Lian-hua
authors.initials: LH
authors.lastname: Han
authors.forename: Wen-ping
authors.initials: WP
authors.lastname: Jiang
mesh_terms: D000085962:Angiotensin-Converting Enzyme 2; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D015153:Blotting, Western; D004195:Disease Models, Animal; D004656:Enalapril / Q000494:pharmacology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006973:Hypertension / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology; D009206:Myocardium / Q000201:enzymology*; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D012333:RNA, Messenger; D004656:Enalapril; D007703:Peptidyl-Dipeptidase A; C000705329:Ace2 protein, rat; D000085962:Angiotensin-Converting Enzyme 2