ULTRASOUND EVIDENCE OF ATHEROGENESIS IN MOUSE LEMUR PRIMATES

International audienceIntroduction The grey mouse lemur is an interesting alternative to transgenic models for the study of normal and pathological ageing [1]: aged animals (>5 years old) spontaneously and progressively develop sensori-motor deficits, alterations of biological rhythms, of thermal regulation, of metabolism, as well as cognitive decline and cerebral atrophy [2]. We here report for the first time aged-related vascular abnormalities, as detected by ultrasound imaging (US) performed at different locations. Methods Twelve females of 1 to 8 years old were studied by ultrasound imaging (Vevo 770, Visual Sonic, with a 20-60Hz mechanical probe) in search for morphological and functional abnormalities of arterial walls at the level of the aortic arch and the common carotids. Total thickness (TT), intima-media thickness (IMT) and extra-media thickness (EMT, [3]) were measured by a blinded, experienced investigator. Pulsatility was expressed as the percentage of variation between the diastolic and systolic diameters. Nine animals underwent blood sampling for LDL subfraction analysis using the Lipoprint system (Quantimetrix). Heart, aorta and carotids of three animals were kept in formol and processed for histology. Results Focal thickenings of carotid walls were observed on B-mode images in 5 out of 6 old animals (Fig. 1). Systematic proximal-wall measurements on M-mode images showed significantly higher carotid TT, IMT and EMT in aged vs young animals, along with decreased pulsatility (Fig. 2). LDL analysis and histology are in progress. Conclusions Using different US indexes of vessel wall functionality [3], we report in vivo evidence of atherogenesis in aged mouse lemurs. Therefore, this species holds promise as a new primate model of atherosclerosis