Characterization of blood biochemical markers during aging in the Grey Mouse Lemur (Microcebus murinus): impact of gender and season

BACKGROUND: Hematologic and biochemical data are needed to characterize the health status of animal populations over time to determine the habitat quality and captivity conditions. Blood components and the chemical entities that they transport change predominantly with sex and age. The aim of this study was to utilize blood chemistry monitoring to establish the reference levels in a small prosimian primate, the Grey Mouse Lemur (Microcebus murinus). METHOD: In the captive colony, mouse lemurs may live 10–12 years, and three age groups for both males and females were studied: young (1–3 years), middle-aged (4–5 years) and old (6–10 years). Blood biochemical markers were measured using the VetScan Comprehensive Diagnostic Profile. Because many life history traits of this primate are highly dependent on the photoperiod (body mass and reproduction), the effect of season was also assessed. RESULTS: The main effect of age was observed in blood markers of renal functions such as creatinine, which was higher among females. Additionally, blood urea nitrogen significantly increased with age and is potentially linked to chronic renal insufficiency, which has been described in captive mouse lemurs. The results demonstrated significant effects related to season, especially in blood protein levels and glucose rates; these effects were observed regardless of gender or age and were likely due to seasonal variations in food intake, which is very marked in this species. CONCLUSION: These results were highly similar with those obtained in other primate species and can serve as references for future research of the Grey Mouse Lemur.