Effect of guanfacine and methyldopa on insulin secretion in diabetic rabbits

ABSTRACT

Two different alpha 2-adrenoceptor agonists, guanfacine and methyldopa, were used to evaluate the role of alpha 2-adrenoceptor stimulation on insulin release, serum glucose level and glucose tolerance in diabetic rabbits. Both drugs induced a remarkable inhibition of insulin release accompanied by an increase in serum glucose and impairment of glucose tolerance. Methyldopa showed weaker effects than guanfacine. It was concluded that, in diabetic fasting rabbits, stimulation of alpha 2-adrenoceptors depresses basal insulin secretion. It was also suggested that successive alpha 2-adrenergic stimulation by alpha 2-adrenoceptor agonists in diabetic persons might to be a harmful adjunct to diabetes mellitus