It has long been known that some diguanidine compounds, such as Synthalin A and B, produce hypoglycemia in man 1 and in laboratory animals.2,3 In a systematic search for orally effective hypoglycemic compounds, Ungar et al.4 found that phenethylformamidinyliminourea, a condensed diguanidine (or a diguanide), was effective. The compound has been called DBI by others,4,6 but since the diguanide group is presumably essential for the hypoglycemic action, we have used the term phenethyldiguanide (PEDG) (Fig. 1).
These studies are a part of our efforts to define and elucidate the actions of this compound. The effects of PEDG on blood sugar in intact and eviscerated animals, on the hepatic glucose output, and on the degradation of insulin I131 were investigated.
Synthalin A, even in very small doses, is toxic and produces histological changes in the liver, kidneys, and pancreas.3 A study of the toxicity of PEDG was done because