Gastrin responses in patients with adrenergic insufficiency.

High basal gastrin levels in pure autonomic failure could result from peripheral vagus nerve involvement, whereas the increased response during hypoglycaemia may reflect adrenergic supersensitivity. A reduced gastrin increment in multiple system atrophy was found following insulin-hypoglycaemia and is consistent with decreased gastrin release secondary to diminished central sympathetic nervous system activation in the absence of peripheral denervation supersensitivity.