Vascular endothelial growth factor: a novel endocrine defensive response to hypoglycemia.

Glucose, the most important fuel for the brain, is supplied by the actions of counterregulatory hormones and the sympathetic nervous system. Yet to obtain access to the brain, glucose must pass the blood-brain barrier. Here we show that vascular endothelial growth factor (VEGF), a potent regulator of blood vessel function, is a candidate hormone for facilitating glucose passage across the blood-brain barrier under critical conditions.

Preserved hypothermic response to hypoglycemia after antecedent hypoglycemia.

Hypoglycemia is known to decrease the body temperature and to stimulate counterregulatory hormone secretion. Although it is well established that antecedent hypoglycemia reduces the hormonal response to subsequent hypoglycemia, the effects of antecedent hypoglycemia on the subsequent hypothermic response are obscure. In the present study, body temperature was measured orally during a total of 90 glucose clamp experiments in 45 healthy men.

Glucose metabolism rather than insulin is a main determinant of leptin secretion in humans.

Circulating plasma insulin and glucose levels are thought to be major regulators of leptin secretion. There is evidence from in vitro and animal experiments that glucose metabolism rather than insulin alone is a main determinant of leptin expression. Here, we tested the hypothesis that in humans also leptin secretion is primarily regulated by glucose uptake and only secondarily by plasma insulin and glucose.