Lithium concentration in biological samples and gender difference in athletic horses.

Lithium (Li+ ) represent a substance particularly used for human's psychiatric disorders but its therapeutic effect is not well documented for equine specie. For its neurotrophic effect it may be used as a possible doping substance in horses sport competitions. The purpose of the present study was to determinate the different bioaccumulation of lithium concentration in different biological substrates (blood, serum, mane and tail), in 30 horses (15 geldings and 15 mares) and haematological parameters as blood biomarkers for lithium bioaccumulation. (RBC, WBC, HGB, HCT, MCV, MCH, MCHC). The lithium concentration in substrates were analysed by one-way ANOVA. Unpaired t-test was performed between geldings and mares in all substrates. Furthermore, a single regression analysis (Pearson) has been carried out between lithium concentration of all biological substrates with each other and between the substrates with the haematological parameters. Our results showed a higher value of lithium concentration in blood and mane in total, and a higher value in mane and tail for mares than geldings. Correlation analysis showed only a significative correlation among blood, serum and tail. A significative statistical correlation between blood and all haematological parameters except for WBC and MCH was observed. A significative correlation was showed for serum and RBC, HGB and HCT and between tail and HGB, HCT and MCHC. No significative correlation was observed for mane and haematological parameters. These data could be useful for the evaluation of biodistribution of lithium in athletic horse in relation to different gender for future use in doping control.