CHANGE IN LEVELS OF CYCLIC-AMP AND CYCLIC-GMP DURING PREGNANCY AND LARVAL DEVELOPMENT OF THE TSETSE-FLY, GLOSSINA-MORSITANS

cAMP and cGMP levels change very little in response to feeding and mating, but during pregnancy and at parturition major changes can be detected in both the mother and larva. In both the female head and larva (whole body) cAMP levels reach a peak at parturition. In the larval brain and ring gland cAMP is at its lowest at parturition but rises sharply, reaching a peak 1.5 h later at the time of pupariation. Although cAMP levels in the head and thorax are consistently 10-60 times greater than levels of cGMP, both the female abdomen and larva contain high concentrations of cGMP with a ratio of cAMP:cGMP approaching 1:1. In the abdomen, the pattern of high cGMP closely parallels the activity cycle of the female''s milk gland.