A possible role for cyclic nucleotides in the regulation of erythrocyte shape and permeability.

Erythrocytes treated with vinblastine or colchicine become spheroidal, more permeable to sodium, and of diminished deformability; upon reinjection they are rapidly sequestered and destroyed in the spleen. These deleterious effects are competitively inhibited by the cyclic nucleotides, guanosine 3',5'-monophosphate or adenosine 3',5'-monophosphate. The data suggest that cyclic nucleotides may be involved in normal erythrocyte shape and survival by interacting with membrane components that also react with vinblastine and colchicine. Similar interactions have been noted previously in diverse proliferating cells as well.