A study of the citric acid cycle in the tick hyalomma dromedarii

1. 1. The citric acid cycle in engorged nymphs of the camel tick Hyalomma dromedarii was studied by the simultaneous isolation and determination of the cycle acids. Acetate-1- 14C and certain co-factors were incubated with homogenates made from the whole tick tissue in the presence and absence of inhibitors. 2. 2. The citric acid cycle occurred in this tick but its activity appeared to be of a low level. 3. 3. Other mechanisms could also be operative along with the citric acid cycle which would provide substrates for the cycle. 4. 4. A highly labelled unidentified acid was formed in the tick tissue along with the members of the cycle.