• Shamoon, Harry (PI)

Project: Research project

Project Details


A number of studies have shown that the increase in counterregulatory
hormone concentrations induced by hypoglycemia is reduced in
insulin-dependent diabetics (IDD's) as compared to nondiabetic controls.
In particular, the failure of plasma epinephrine levels to rise normally in
IDD's occurs together with the impaired secretion of glucagon. This leads
to loss of the acute hormonal response to insulin-induced hypoglycemia
which, in turn, results in the lack of rebound in hepatic glucose output
posthypoglycemia and delayed recovery to safe blood glucose
concentrations. This proposal will study the mechanism underlying the loss
of an adequate epinephrine response in IDD's and therapeutic implications
of this. Specifically, studies are designed to evaluate the scope of the
hormonal abnormality in Type I diabetes in humans by using multiple stimuli
to assess secretory responses of epinephrine, glucagon, cortisol, growth
hormone, and norepinephrine using non-hypoglycemic and hypoglycemic
stimuli. Since preliminary evidence suggests that exercise may potentiate
the catecholamine response to hypoglycemia in normal but not diabetic
subjects, studies are proposed to explore the relative roles of epinephrine
secretion or clearance and the severity of the exercise stimulus in this
phenomenon. Experiments in which blood glucose will be held constant
during exercise will determine whether the hormone responses to exercise
are related to the glucose level, whether their response is still modulated
by changes in glucose and whether the defect in epinephrine response is
also present in non-insulin dependent diabetes. Finally, the role of
epinephrine in exercise-induced glucose production will be evaluated.
These studies may help to define the cause(s) of the observed hormonal
deficits in IDDM and serve to clarify the role of exercise in the therapy
of diabetes.
Effective start/end date12/31/891/1/90


  • Endocrinology, Diabetes and Metabolism
  • Medicine(all)


Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.