Helical polysomes induced by aflatoxin B1 in vivo : A new hypothesis for helix formation by chemicals and carcinogens

We have studied the induction of helical polysomes by aflatoxin B₁ in liver and kidney cells from rat and mouse. We succeeded in giving to reticulocyte polysomes a shape resembling helices after in vitro treatment with O-methylthreonine which is used as an inhibitor of polypeptide chain termination. From this and knowing the site of action of aflatoxin B₁ on rat liver polysomes, we hypothesize that the induction of helical polysomes in tissues from adult animals treated by chemicals or carcinogens is due to the inhibition of release of ribosomes from the messenger RNA (mRNA). Theoretical studies of protein synthesis inhibition are in agreement with this new hypothesis.