Membrane studies in Huntington's disease: steady-state fluorescence studies of intact erythrocytes.

Recent evidence suggests that a membrane abnormality may be present in Huntington's disease (HD), including peripheral tissues such as erythrocytes. Steady-state fluorescence spectroscopy was performed on intact erythrocytes from patients with HD and from normal age- and sex-matched controls. Fluorescent probes with known specificity for certain membrane areas were used to survey membrane dynamics; these probes included fluorescamine, which binds to primary amines on the cell surface, and both 12(9)-anthroyl stearate, 12(9)AS, and 2(9)-anthroyl stearate, 2(9)AS, which insert at different depths in the hydrocarbon core of membranes. In the intact HD erythrocyte, fluorescamine revealed decreased polarization, 12(9)AS showed increased polarization, and 2(9)AS showed no difference as compared to normal erythrocytes. These studies suggest that fluorescamine, attached to primary amines of the cell surface in intact HD erythrocytes, has increased rotational mobility whereas the anthroyl moiety of 12(9)AS in the hydrocarbon interior has decreased rotational mobility. These studies thus support the concept of a membrane abnormality in HD.