LEVELS OF BIOGENIC-AMINES IN LARVAE AND ADULTS OF THE RAT HOOKWORM, NIPPOSTRONGYLUS-BRASILIENSIS (NEMATODA)

Norepinephrine, 5-hydroxytryptophan, octopamine, dihydroxyphenylacetic acid, N-acetyldopamine, dopamine, 5-hydroxyindoleacetic acid, N-acety lserotonin, tyramine, tryptophan and serotonin in larvae (third free s tage and parasitic stages) and adult males and females (at defined age s during the intestinal phase) of the parasitic nematode Nippostrongyl us brasiliensis were quantified simultaneously by high-performance liq uid chromatography with electrochemical detection. Biogenic amine leve ls depended on the stage, the age and the sex of parasites and on envi ronmental conditions. Their physiological roles in reproductively comp etent adults of this nematode are discussed in relation to exuviation and egg laying. Parallel fluctuations in free ecdysteroids and norepin ephrine were observed in females from the same worm populations. (C) 1 997 Elsevier Science Inc.