Opiate receptor avidity in the thalamus is sexually dimorphic in the elderly

Opiate receptor avidity (B'(max)/F-D), was measured in the subcortex of nin e females (five healthy subjects, four Alzheimer patients) and 15 males (se ven healthy subjects, eight Alzheimer patients), 51-75 years of age, with t he opiate receptor antagonist 6-deoxy-6-beta-[F-18]fluoronaltrexone (cyclof oxy, CF) and a positron emission tomograph. CF avidity was 27.5% less in th e thalamus of healthy women compared to healthy men and 48.5% less in Alzhe imer disease female patients compared to male patients. (C) 2000 Wiley-Liss , Inc.