[On the influence of oral antidiabetics on protein biosynthesis in vitro (author's transl)]

Inhibition of protein synthesis is one of the few side effects of sulfonylureas and biguanides. Regarding our results obtained with hepatic polyribosomes from diabetic and from control animals, with ribosomes directed by polyuridylic acid as a synthetic messenger, and by centrifugation of the ribosomes through sucrose gradients there is evidence of a direct inhibiting effect of tolbutamide on liver ribosomes. The effect of butyl-biguanide depends on the system used for in vitro protein synthesis. While it is inhibiting protein synthesis of normal liver ribosomes regardless of the attached messenger, it stimulates the incorporation of amino acids by ribosomes from diabetic rats directed by endogenous or by synthetic messengers. The specific pattern of ribosomal distribution in sucrose gradients is unchanged by the administration of tolbutamide to the animal prior to its decapitation. However, butyl-biguanide leads to reduction of the polyribosomal portion of liver ribosomes from normal animals while it is without any furhter effect on the amount of polyribosomes already reduced in diabetes mellitus.