Immunoprotective role of cyanocobalamin [vitamin B-12] in heat-induced splenic white pulp damage in rats: an immunohistological study

ABSTRACT

To evaluate the immunoproteetive role of Gyanocobalomin on detrimental effects of heat induced stress on splenic white pulp T-cells [cellular immunity]. This experimental study was conducted in the Anatomy Department, BMSI, JPMC, Karachi from March 2009 to May 2009. Thirty male albino rats weighing about 180-200 grams were used and divided into three groups labeled A, B and C. Group A served as control. Group C received heat and protection with Cyanocobalmin at an intrapesitoneal dose of 0.8 mg / kg body weight per day before heat-induction. After 6 weeks of treatment animals were sacrificed. The blood samples were collected and assayed for plasma ACTH concentration by ELISA method. For immunohistochemistry 4-micron thick-formalin fixed paraffin- embedded splenic sections were obtained on polysine coated slides. Antigens were retrieved by HIER technique and stained with immunomarker anti-CD3 for the evaluation of T-Lymphocytes. Five - micron thick hacmatoxylin-eosin sections were prepared for other morphological details. Control group A reveals normal architecture of splenic white pulp. Heat induced group B showed atrophic white pulp and hypocellularity in all compartments. Cellular loss was largely due to apoptosis. Most of the splenic periarteriolar lymphoid sheaths and marginal zones contain clumps of apoptotic cells engulfed by tangible body macrophages. Protective group C shows comparable architecture with control. Plasma ACTH concentration in group B [67.63 +/- 0.69 pg/ml] statistically increased [P<0.001] compared to control group [23.94 +/- 0.87 pg/ml] and significantly changed [P<0.001] when compared with group C [34.71 +/- 1.24 pg/ml] Present study concludes that cyanocobalamin has substantial immunopotentiating effects on immune organs and cells of cellular immunity [T-lymphocytes] and it may compensate the detrimental effect of heat-stress on both humans and animals