THYROID STATUS AND ADENOSINE-TRIPHOSPHATASE ACTIVITY IN EXPERIMENTAL TRYPANOSOMA-CONGOLENSE INFECTION IN RABBITS

The effect of trypanosome infection on the plasma levels and ratios of tri-iodothyronine (T-3) and thyroxine (T-4) as well as the activity o f mitochondrial adenosine triphosphatase (ATPase) were investigated. T hree groups of sexually mature white New Zealand rabbits were used. Gr oup 1 consisted of the normal non-infected rabbits, group 2 were exper imentally infected with Trypanosoma congolense and group 3 were infect ed but given replacement doses of thyroxine. The infected animals (gro up 2) showed a rapid decline in both T-3 and T-4 but an increase in th e T-3/T-4 ratio indicating differential production or clearance rates between the two hormones. The mitochondrial ATPase activity was found to be depressed in the infected group whereas there was no significant difference in the ATPase activity between the non-infected (group I) and infected-treated animals (group 2). It is postulated that trypanos ome induced hypothyroid status may play a role in the impairment of mi tochondrial ATPase activity, a key enzyme in energy metabolism.