Abstract
Domestication of Cricetomys gambianus, Waterhouse (African Giant Rat), an important source of animal protein in the sub-Saharan rural communities, is on-going. However, there are no baseline data on the trace element profile of this rat, in health and in disease. Therefore, this study determined the sexual differences in the effect of Trypanosoma congolense infection on the levels of plasma and erythrocyte trace elements in the adult rats. Twenty rats were divided into four groups comprising of five rats each. The infected female (IF) and male (IM) groups received T. congolense (Bassa strain; 3.75 × 105 trypanosomes/ml/rat), intraperitoneally, while the control groups (CF and CM) received normal saline. The plasma and cytosol (10% erythrocytes) levels of Mg, Mn, Cu, Fe and Zn were determined on Day 12 post-infection, using atomic absorption spectrophotometry. Plasma Mn level was significantly decreased (p<0.001) in the IM (10.35±0.82ppm) relative to the MC (13.99±0.56 ppm) but non-significantly altered (p>0.05) in the IF (7.54 ± 0.68 ppm) relative to the CF (6.82±0.48ppm). Plasma Zn level was also significantly decreased (p<0.001) in the IM (0.48±0.06ppm) relative to the MC (2.03±0.14ppm) but non-significantly altered (p>0.05) in the IF (1.58±0.39ppm) relative to the CF (2.69±0.47ppm). Erythrocyte Cu levels showed significant (p<0.001) sex and infection effects: (CM 0.76±0.34 ppm; IM 0.22±0.08 ppm; CF 4.79±0.49 ppm and IF 2.96±0.24 ppm). Significant (p<0.05) sex and infection effects were also observed in the erythrocyte Zn levels with the IM (3.97±0.4ppm) being lower than the IF (4.33±0.91ppm), and IF (4.33±0.91ppm) being lower than CF (10.18±1.08 ppm) and CM (7.74 ± 2.34 ppm) being lower than CF (10.18±1.08 ppm). Trypanosoma congolense infection and/or sexual differences altered the levels of Copper, Manganese and Zinc in the African giant rat. These observations may be important in the management of trypanosomosis in naturally susceptible animals.

Key words: Cricetomys gambianus; Trypanosoma congolense infection; Trace element; Sexual differences.