Abstract

I. A. Umar*, I. O. Igbokwe, J. J. Omage, D. A. Ameh, H. O. Kwanashie and K. A. N. Esievo

The effect of intravenous infusion of a solution of lactose-in-normal saline on the course of Trypanosoma vivax induced anaemia in Zebu yearlings was investigated. The animals were infected with 11 x 106 trypanosomes by jugular venipuncture and lactose-in-normal saline infusion started on day 6, post-infection (p.i). Three four-hourly doses of 0.5 g lactose/kg body weight were administered to each infected yearling in the experimental group daily for five days, while the infected control yearlings received no lactose-infusion. The experiment was terminated on day 13, p.i. Parasitaemia in the lactose-infused yearlings was scorable throughout the duration of experiment while parasites could not be detected in the blood of the infected control yearlings between days 7 and 9, p.i. Serum free sialic acids (FSA) concentration was also consistently higher in the lactose-infused yearlings than in the lactose-free ones. In the before lactose infusion (BL) period the PCV of the lactose-infused group dropped at a significantly (P < 0.05) faster rate than in the lactose-free one. In the DL (during lactose infusion) period, the rate and magnitude of decline in PCV was significantly lower in the lactose-infused yearlings than in the lactose-free animals. When lactose infusion was stopped (AL) the rate and magnitude of PCV decline became greater in the lactose-infused yearlings than in the lactose-free ones. It was thus concluded that lactose ameliorated anaemia, by inhibiting the sequestration of desialylated erythrocytes from the blood stream of T. vivax-infected yearlings. This manifested in the reduced magnitude and rate of decrease in PCV in the lactoseinfused infected yearlings.