Proteolipid and bovine aorta calcification, in vitro.

Proteolipid was examined for nucleation of bovine aorta calcification. Tissue homogenates were tested for in vitro calcifiability before and after lipid extraction followed by similar tests of the extract and its fractions. The tissue calcified before but not after lipid extraction. Of the lipid fractions, only proteolipid calcified. Within the constraints imposed, proteolipid is required for initiation of bovine aorta calcification, in vitro.