Occurrence of cardiovascular calcifications in normal, aging rats.
BACKGROUND
Cardiovascular calcification is an independent predictor of morbidity and mortality and increases with age. Animal models are frequently used to investigate the underlying pathophysiology. Only scarce data regarding the effect of aging on calcifications in these animal models are available. The aim of this study is to investigate the occurrence of cardiovascular calcifications in normal, aging rats.


METHODS
A mixed inbred/outbred population of 44 male Lewis/Wistar rats was studied. Group 1 of three-month-old rats, group 2 twelve-month-old, group 3 twenty-four-month-old and group 4 thirty-month-old rats. Calibrated integrated backscatter (cIB) values and blood parameters (creatinine, parathyroid hormone (PTH)) were measured, followed by ex-vivo micro-CT and histology as reference methods.


RESULTS
Cardiovascular calcifications developed with age, as demonstrated by significantly increasing cIB values of the aortic valve and myocardium. This was confirmed by a significant increase in the calcified volume on ex-vivo micro-CT and in the histological calcium score. There was also a significantly higher level of creatinine and PTH with age.


CONCLUSIONS
As in humans, cardiovascular calcifications progressively increase with age in the normal rat. Therefore the aging rat model could be used for studying calcifying cardiovascular disease. cIB might have a value in future studies for the early detection of subclinical calcifications in humans.
Centrum Voor Hart- en Vaatziekten (CHVZ), UZ Brussel, Vrije Universiteit Brussel (VUB), B-1090 Brussels, Belgium. broosens@vub.ac.be
Bram
B
Roosens
Gezim
G
Bala
Steven
S
Droogmans
Jeroen
J
Hostens
Joan
J
Somja
Eléonore
E
Delvenne
Johan
J
Schiettecatte
Philippe
P
Delvenne
Tony
T
Lahoutte
Guy
G
Van Camp
Bernard
B
Cosyns
D000375:Aging / Q000502:physiology*; D000818:Animals; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009202:Cardiomyopathies / Q000000981:diagnostic imaging / Q000503:physiopathology*; D018450:Disease Progression; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D017208:Rats, Wistar; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology; D055114:X-Ray Microtomography