Disturbed function of the pineal gland in familial amyloid polyneuropathy.

In order to estimate the function of the pineal gland, the sympathetic nervous system and the adrenal medulla in patients with familial amyloid polyneuropathy relative to healthy subjects, we have quantified urinary 6-hydroxymelatonin, normetanephrine and metanephrine. Urinary 6-hydroxymelatonin level correlated with neither of two O-methylated catecholamine levels in healthy subjects. The excretion of both 6-hydroxymelatonin and metanephrine were reduced in the patient group as compared with the control group, and the normal daily rhythm of 6-hydroxymelatonin was undetectable in the most of the patients. This finding indicates that the function of the pineal gland is disturbed in familial amyloid polyneuropathy.