Changes in the blood of newts,Notophthalmus viridescens, following the administration of hydrocortisone

Summary

Adult newts,Notophthalmus viridescens, were injected with suspensions of hydrocortisone acetate (experimentais) or with distilled water (controls). Forty-eight and 72 hours after treatment, blood smears were prepared, and differential counts of leucocytes were made for the experimental and control animals. At 48 hours, the distributions of neutrophils, eosinophils, basophils, monocytes and lymphocytes were much the same in the two groups of newts (Table 1). However, by 72 hours after injection, increases in neutrophils and decreases in lymphocytes were obvious in the animals which had received hydrocortisone. Such changes were not seen in the controls (Table 2). The changes in the distribution of the white cells seen 72 hours after treatment are very similar to those known to occur in mammals treated with adrenal steroids and to those described earlier in two species of frogs injected with hydrocortisone. Details of some differences in the responses of the amphibians are discussed.