Effect of vitamin C supplementation on some leukocyte parameters in American mink (Neovison vison) with abnormal granulogenesis.

Sapphire mink, a mutant colour variant of American mink, is an animal model of the Chediak-Higashi syndrome (CHS). As in CHS, there are enlarged cytoplasmic granules in various cell types including leukocytes in Sapphire mink due to abnormal granulogenesis. Such cellular abnormality leads to a weakening of the immune defence as a consequence to the development of infections. A study with Sapphire mink and Standard mink was conducted to evaluate the immunostimulant effect of vitamin C (VC) supplementation (100 mg/day) on some leukocyte parameters. In the end of the 20-day treatment period, blood samples were collected to determine hematological (total and differential leukocyte counts, red blood cells (RBC) counts, and haemoglobin level) and cytochemical (activity and staining area of myeloperoxidase, eosinophilc peroxidase, alkaline phosphatase, and alpha naphthyl acetate esterase) parameters. The study showed that total leukocyte counts, segmented neutrophil counts, and monocyte counts were significantly (p < 0.05) higher in Sapphire mink from the VC-supplemented group than in those receiving the control diet. These results indicate that VC supplementation may have a positive effect on immunity in Sapphire mink. Another interesting finding is an increase in the number of neutrophils with enlarged granules and lysosomal enzyme-positive area in VC-supplemented mink as compared with those fed the control diet. These observations suggest that VC supplementation can affect the lysosomal apparatus of leukocytes.