Autonomic nervous system abnormalities in cystic fibrosis

The basic defect in cystic fibrosis, the most common lethal genetic diseases of white Americans, is unknown, but the character of the generalized exocrinopathy suggests some disorder of the regulation and control of the process of glandular secretion. Definite abnormalities in all branches of the autonomic nervous system have been demonstrated in patients with cystic fibrosis, including increased sensitivity to alpha-adrenergically stimulated pupillary dilation; increased responsiveness to cholinergic stimulation of pupillary constriction, parotid saliva secretion, and eccrine sweat secretion; and decreased responsiveness to beta-adrenergic stimulation of the cardiovascular system as well as circulating lymphocytes and granulocytes. Since these abnormalities also occur in asymptomatic heterozygotes for cystic fibrosis (parents of patients), they are likely to be inherited characteristics and not secondarily acquired. This constellation of inherited autonomic abnormalities--alpha-adrenergic and cholinergic hyperresponsiveness and beta-adrenergic resistance--may contribute to the pathophysiology of cystic fibrosis and may also be an important clue to the nature of the basic defect.