Glucose production by the perfused liver of the spiny mouse (Acomys cahirinus): sensitivity to glucagon and insulin.

Hepatic glucose production and its responses to glucagon and insulin were studied in perfused livers obtained from spiny mice (Acomys cahirinus)--rodents characterized by normoglycemia, decreased glucose tolerance and decreased insulin secretion--and from Swiss albino mice. The dose-response characteristics of glucagon-induced hepatic glucose output were similar in spiny and albino mice. However, maximally stimulated glucose production were significantly lower in the spiny mouse. Furthermore, the liver of the spiny mouse was more sensitive to the action of insulin: 0.5 X 10(-6) M insulin significantly inhibited the action of glucagon in spiny mice but not in albino mice. It is proposed that the increased sensitivity of the hepatic glucose output to insulin and the decreased maximal stimulation by glucagon may be factors that limit the negative effects of the impaired insulin secretion in spiny mice, thereby reducing the severity of the glucose intolerance. Analogous mechanisms may be present in the early stages of the diabetic syndrome in man.