Original Research Article
Year: 2018 | Month: July-September | Volume: 3 | Issue: 3 | Pages: 7-10
Immunopathological Alterations Induced by Lead Exposure in Rat
Visiting Faculty, Dr Giri Lal Gupta Institute of Public Health, Lucknow University New Campus, Lucknow
The impact of lead toxicity on human health is currently an area of intense interest due to ubiquity of exposure. Its presence is considered unique in the sense that it is difficult to remove from the environment once it enters in it. Hence, studies related to immunotoxic effects of chronic lead exposure were carried out in adult male inbred Wistar rats following 250µ2g of lead acetate per kg body weight, given daily for 60 days in drinking water. Organ weight/ body weight and histology (light microscopic and electron microscopic studies) were used as major parameters. Mesenteric lymph nodes of exoposed rats showed a decrease in somatic tissue index by 13%. Atrophy of lymph nodes as revealed by marked reduction in the number and size of follicles with inconspicuous germinal centre was observed. In comparison to cortex, paracortical and medullary regions showed higher degree of damage, resulting into loss of demarcation between the cortex and medulla. Under electron microscope, condensation of material in the vicinity of nuclear membrane and degeneration of mitochondrial cristae with increased electron dense material in mitochondrial matrix in most of the lymphocytes were observed. Chronic lead exposure induced significant increase in somatic tissue index of spleen i.e. 32%. Diffused atrophy of the white pulp with marked reduction in the number of lymphocytes within periarteriolar lymphocyte sheath was apparent. There was an increase in extramedullary haemopoiesis and hyperplasia of B lymphocytes in the marginal zone and follicles in red pulp. The presence of haemosiderin, a pigmentous material of yellow – brown cytoplasmic granules was observed in macrophages of red pulp. The number of megakaryocytic significantly increased throughout the tissue section was seen under light microscope. Hypertrophy of rough endoplasmic reticulum, vesiculation of smooth endoplasmic reticulum, vacuolation in the matrix of mitochondria and loss of mitochondrial cristae were the remarkable ultra structural changes observed in the different cells of the spleen. Finding of the present study indicates that chronic lead exposure adversely affects normal architecture of the lymphoid organs (lymph node and spleen) in rats.
Keywords: Lead, toxicity, lymph node, spleen.