Plasma catecholamines do not respond to insulin-induced hypoglycemia in a teleost, Anguilla rostrata.

The importance of epinephrine as a counterregulatory hormone in hypoglycemia is still debated. In the American eel (Anguilla rostrata), a species particularly sensitive to the hyperglycemic effect of exogenous epinephrine, insulin-induced hypoglycemia does not provoke an increase of plasma catecholamines; nor does a 35-fold rise of endogenous epinephrine within 5 min cause a statistically significant hyperglycemia. Together with findings in several other species of greatly varying phylogenetic position, these observations suggest that in vertebrates plasma epinephrine does not have significant, if any, glucoregulatory functions.