Protein intensity changes in the hemoglobin and plasma electrophoretic patterns of Oreochromis niloticus in response to single and combined Zn and Cd exposure

The purpose of this study was to evaluate the effects of metals on the electrophoretic patterns of hemoglobin and blood plasma proteins of Oreochromis niloticus. Fish were exposed to 0.5 and 5.0 mg/L Zn, 0.1 and 1.0 mg/L Cd, and 0.5 mg/L Zn + 0.1 mg/L Cd, and 5.0 mg/L Zn + 1.0 mg/L Cd mixtures for 7 and 28 days. In all concentrations tested, electrophoretic pattern of hemoglobin and plasma proteins by cellulose acetate electrophoresis consist of three and eight bands, respectively. The three bands for hemoglobin are one cathodic (Hb1) and two anodic (Hb2 and Hb3) bands. The protein intensity in hemoglobins of fish following Zn, Cd, and Zn + Cd exposures decreased in Hb1, whereas it increased in Hb3. The eight bands for plasma proteins are 60, 78, 87, and 94 kDA high molecular weight proteins (HMP) for four bands and 120, 132, 176, and 273 kDA very high molecular weight proteins (VHMP) for four bands. The level of 60, 78, and 94 kDA HMP and 120, 132, and 176 kDA VHMP increased in response to single and combined Zn and Cd exposure. Also, there was increasing level of the metals in the whole blood with increasing concentrations of metals in the exposure medium and with increasing duration of exposure.