Occurrence of cardiovascular calcifications in normal, aging rats

BackgroundCardiovascular 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.MethodsA 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.ResultsCardiovascular 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.ConclusionsAs 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.

► We investigated the occurrence of cardiovascular calcifications in aging rats.
► We used integrated backscatter for the detection of cardiovascular calcifications.
► Cardiovascular calcifications progressively increase with age in the normal rat.
► Integrated backscatter might be used for the early detection of calcifications.