Cytotaxin-induced cAMP peak in granulocytes: its relationship to crawling movements, chemokinesis and chemotaxis

The relationship between the short transient intracellular increase in cAMP levels on the one hand and chemotaxis or crawling movements on the other hand was investigated using human and equine granulocytes. C5ades arg, f-met-leu-phe, human serum albumin and immunoglobulin were used as stimulating agents. There was no strict correlation between the induction of crawling movements or of chemokinesis in general and the generation of the cAMP peak. But there was so far a strict parallelism between the occurrence of the chemotactic response and the cAMP peak. However, the magnitude of the peak was not representative for the extent of directional locomotion. It seems possible that cAMP is an essential step in the transduction of the chemotactic response, but there is no proof for a causal relationship as yet.