A study on the B cell activity in protein deficient rats exposed to methyl isocyanate vapour

The effect of MIC on the humoral immunity of the malnourished (protein deficient) subjects has been investigated. A single exposure of MIC (1.60 mg/l) on protein deficient rats showed no significant change in the body weight and mortality rate compared with the normal but the serum protein levels were found significantly low (P less than 0.01) in the protein deficient diet fed control (PDC) ones. Both PDC and protein deficient MIC exposed (PDMIC) rat showed diminished B-cell proliferation with the optimal dose of LPS, compared to the NDC and normal diet fed MIC exposed (NDMIC) group. Furthermore significant suppression (P less than 0.01) in the B-cell activation by LPS was observed in the PDMIC compared to PDC. The total IgM level in PDMIC was 43% less while 26% higher in NDMIC compared to NDC. The total IgG level in PDMIC and NDMIC was higher (20%) compared to NDC, while 25% less in PDC. The antigen specific B-cell immunity was affected in PDMIC, PDC and NDMIC. As the terminal differentiation process of B-cells were found equally affected in both PDC and NDMIC, it appears that MIC has no synergistic effect on the humoral immunity of the protein malnourished host.