Journal of Clinical and Diagnostic Research (Feb 2012)
Evaluation of the Haematological Responses to High Nitrate Exposure in Rabbits
Abstract
Introduction: Nitrate is a common pollutant in the drinking water of Rajasthan as well as in the rest of India. The maximum permissible limit for the nitrate ion in drinking water has been set at 50 mg/l by the WHO and at 45 mg/ l by the Bureau of Indian Standards. In the body, nitrate is reduced to nitrite and the absorption of nitrite leads to methemoglobinaemia. Nitrate toxicity has been observed frequently in ruminants which has been fed on a variety of plant materials which had high nitrate content. Aim: The present study examined a possible correlation between the nitrate concentration in drinking water and the blood profile changes in rabbits. Materials and Methods: Rabbits were selected for the study because the pH of their stomachs was similar to that of human beings. We included 5 groups of rabbits, with 2 rabbits in each group. The groups were named A, B, C, D and E respectively. The nitrate concentrations in the drinking water were 45 mg/l, 100 mg/ l,200 mg / l,400 mg / l and 500 mg/ l in the groups A to E respectively. The group A was considered as the control group. After 120 days of the ingestion of sodium nitrate in drinking water, blood samples were collected from the rabbits of each group and were observed. Results and Conclusion: The maximum haematological parameters such as WBC, lymphocytes, MCHC, RBC, Hb and basophills showed decreased values in the higher groups as compared to the values of the control group. The PCV and MCV showed increased values in the higher groups as compared to the values of the control group. The present study indicated that the symptoms of nitrate toxicity were associated with the low oxygen carrying capacity of blood in the affected animals. Nitrate toxicity is a potential health hazard and the scarcity of data on the nitrate toxicity in blood created an interest in attempting the present study.
