1 Plasma and red blood cell concentrations of amodiaquine (AM) and its metabolite, desethylamodiaquine (DAM), were monitored at intervals up to 21 days after a single oral dose of 600 mg amodiaquine in five normal African subjects 2 Concentrations of AM and DAM were determined using a high performance liquid chromatography technique with a lower limit of sensitivity of 10 ng ml-' for both compounds. 3 AM was not detectable in plasma and red blood cell samples withdrawn from any of the subjects. 4 DAM was detectable in both media. It appeared in the blood 0.5-1 h after administering AM, reached a peak in 1.5-2 h and subsequently declined slowly.5 We conclude that AM is rapidly converted to DAM and its blood concentration, compared with that of DAM, is very low if not negligible.

The odours of the whole body and the secretion of Zonocerus variegatus were easily recognised and perceived by human volunteers. However, the secretion odour is not related to the odour of the food plant consumed by the grasshopper. The repellency of Z. variegalus becomes more pronounced in the 6th. and adult instars whose gland lumens contain an appreciable volume of secretíon. The seeretion odour is so strong that even dilulion does no! affee! its repulsiveness to humans. The secretion had pharmacological properties: it indueed contraction in rat (Rattus rattus) stomach smooth muscle preparations and guinea pig (Cavia porcellus) ileum, and induced oedema formation in the rat hind paw. The secretion was not lethal to the animal s used in this study, effects were temporary and reeovery oecurs after a short time.