Morphological changes of astrocyte-like cells induced by serum beta-lipoprotein in brain cell culture.

When added to brain cell cultures of newborn rats, serum and, in particular, its beta-lipoprotein fraction caused significant morphological transformations of astrocyte-like cells present in the culture. The changes were instantaneous as they appeared within 1 min after addition of beta-lipoprotein and they were characterized by swelling and loss of cellular processes of all astrocyte-like cells present. The lipoprotein effect was reversed after a period of about 7 h. Since the blood-brain and blood-spinal fluid barrier in multiple sclerosis is decreased towards serum macromolecules, i.e. the serum beta-lipoprotein, this protein may enter the central nervous system and thereby initiate a demyelinating process.