Hematological changes in sheep inoculated with natural and Cobalt60-irradiated Crotalus durissus terrificus venom (Laurenti, 1768)

Abstract

ABSTRACT. Natural (NV) and Cobalto 60 -irradiated (IrV) Crotalus durissus terrificus venom were used to evaluate serum production capacity of sheep and possible hematological and biochemical effects. Freeze-dried venom aliquots were diluted in acidified saline solution (NaCl 150 mM, pH 3.0) and irradiated by a Cobalt 60 source at a dose of 5.54 x 102 Gy/h and a concentration of 2.000 Gy. Twelve sheep were divided into two groups of six animals. One group received irradiated venom (IrV) and the other natural venom (NV). Three antigen doses (venom) were administered at monthly intervals. Blood samples were collected weekly for analysis of serum neutralization potency and capacity, complete blood count (CBC), total plasma protein, fibrinogen, albumin, and globulin. At the end of the experiment, the animals were challenged with a LD 50 for sheep and showed no signs of envenoming. The two groups did not present clinical alterations. Results of the total leukocyte count did not present interaction or time factor effect for both groups, but there was a different action between them, with the NV group presenting more cells than the IrV group. The leukocyte increase to 13,000/µl indicates that slight leukocytosis occurred in the week after the first inoculation in the NV group. There was no statistically significant difference between groups in the absolute count of segmented neutrophils, eosinophils, and lymphocytes but there were statistically significant oscillations in values at the different collecting times. The NV group presented an increase in the absolute neutrophil count after the first inoculation that persisted for 5 weeks. In the IrV group, the increase in neutrophils occurred only in the first week returning to normal in the following weeks. The alterations in the neutrophil count are indicative of systemic inflammatory response related to cytokine release; response was more marked in the NV group, showing its greater toxicity.

Clinical Effects of the Immunization Protocol Using Loxosceles Venom in Naïve Horses

“…The bleeding protocol used in the present study caused anemia in horses, evidenced by the progressive reduction and RBC, hemoglobin, and PCV and the observed pale mucous membranes in six of eleven horses after first bleeding (T2), which was similar to findings described earlier [ 14 , 25 ]. Two horses kept PCV under 15% during T2, which shows a clinical concern since, in most of these cases, a blood transfusion is required [ 26 ].…”

New insights into the structural characteristics of irradiated crotamine

“…The indirect process is the main way of interaction and accounts for approximately 80 % of the total effects [ 21 , 22 ]. Previous studies showed that the most appropriate radiation dose for reducing venom toxicity and maintaining immunogenicity in order to increase the production of antiserum is 2 kGy [ 23 – 27 ].…”