Haemolymph octopamine levels during and following flight in the American cockroach, Periplaneta americana L.

Haemolymph octopamine levels of adult male cockroaches (Periplaneta americana) were monitored using high performance liquid chromatography with electrochemical detection. The octopamine concentration of haemolymph increases rapidly in response to experimental handling and the commencement of flight, with 77 and 123% elevations, respectively, observed within 1 min of initiating these activities. Resting levels are rapidly restored when flight ceases. The results support the suggestion that octopamine mediates a generalized sympathetic-like response to excitation.