The effects of polyamines on the cyclic amp efflux and metabolism in E. coli b cells

1. 1. The effects of polyamines spermine, spermidine and putrescine have been investigated on the adenylate cyclase and phosphodiesterase activities bound to E. coli B-cell membranes. 2. 2. Putrescine, which is physiologically present in bacteria, affects the cAMP metabolism in a coordinate manner, depressing the adenylate cyclase and stimulating the phosphodiesterase activities. In vivo this is reflected by a decreased cAMP efflux toward the external medium. 3. 3. Spermidine stimulates the phosphodiesterase activities but has no effect on the adenylate cyclase; furthermore no effect was observed in vivo on the cAMP efflux. li[4. Spermine stimulates both the enzymic activities but with a prevailing effect on the adenylate cyclase. In vivo the effect is an increase in the cAMP efflux. 4. 5. In vivo the intracellular cAMP content is anyway not modified in presence of polyamines, in contrast with (and may be because of) the broad variation of the nucleotide efflux toward the external medium.