Paricalcitol downregulates myocardial renin-angiotensin and fibroblast growth factor expression and attenuates cardiac hypertrophy in uremic rats.
BACKGROUND
Vitamin D attenuates uremic cardiac hypertrophy, possibly by suppressing the myocardial renin-angiotensin system (RAS) and fibroblast growth factors (FGFs). We compared the suppression of cardiac hypertrophy and myocardial expression of RAS and FGF receptor genes offered by the vitamin D analog paricalcitol (Pc) or the angiotensin-converting enzyme inhibitor enalapril (E) in experimental uremia.


METHODS
Rats with 5/6 nephrectomy received Pc or E for 8 weeks. Renal function, systolic blood pressure, and cardiac hypertrophy were evaluated. Myocardial expression of RAS genes, brain natriuretic peptide (BNP), and FGF receptor-1 (FGFR-1) were determined using quantitative reverse-transcription (pRT)-PCR.


RESULTS
Blood pressure, proteinuria, and serum creatinine were significantly higher in untreated uremic animals. Hypertension was significantly reduced by E but only modestly by Pc; however, cardiac hypertrophy in the untreated group was similarly attenuated by Pc or E. Upregulation of myocardial expressions of renin, angiotensinogen, FGFR-1, and BNP in untreated uremic animals was reduced similarly by Pc and E, while the angiotensin II type 1 receptor was downregulated only by E.


CONCLUSIONS
Uremic cardiac hypertrophy is associated with activation of the myocardial RAS and the FGFR-1. Downregulation of these genes induced by Pc and E results in similar amelioration of left ventricular hypertrophy despite the different antihypertensive effects of these drugs.
Department of Pediatrics, Division of Pediatric Nephrology, University of Miami Miller School of Medicine, Miami, Florida.
Michael
M
Freundlich
Yan C
YC
Li
Yasmir
Y
Quiroz
Yanauri
Y
Bravo
Wacharee
W
Seeherunvong
Christian
C
Faul
Jose R
JR
Weisinger
Bernardo
B
Rodriguez-Iturbe
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D006332:Cardiomegaly / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D004195:Disease Models, Animal; D015536:Down-Regulation; D004656:Enalapril / Q000494:pharmacology; D004872:Ergocalciferols / Q000494:pharmacology*; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D006973:Hypertension / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control; D008297:Male; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D009392:Nephrectomy; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012084:Renin-Angiotensin System / Q000187:drug effects* / Q000235:genetics; D014511:Uremia / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D004872:Ergocalciferols; D012333:RNA, Messenger; D005346:Fibroblast Growth Factors; C084656:paricalcitol; D004656:Enalapril; C496350:Fgfr1 protein, rat; D051496:Receptor, Fibroblast Growth Factor, Type 1
Vitamin D; cardiac hypertrophy; fibroblast growth factor; paricalcitol.; renin-angiotensin system; uremia