DESTRUCTION OF LACIS CELLS OF THE JUXTAGLOMERULAR APPARATUS IN THE HYPERCHOLESTEROLEMIC RABBIT

During a study of experimentally induced atheromatosis in hypercholest erolemic rabbits we found a heavy infiltration of the lacis cell field (G field) by lipids in the kidney. A systematic study was done in 12 rabbits receiving a dietary cholesterol supplement of 0.3% for 26 week s and in a animals receiving a supplement of 2% for 8 weeks. Standard histology, immunohistochemistry for a-smooth muscle cell actin and wit h the macrophage specific antibody RAM 11, and transmission electron m icroscopy were performed. In the low cholesterol, long duration group, 90% of the G fields were involved. The lipid accumulation was mainly extracellular. The lacis cells contained moderate numbers of medium si zed lipid vacuoles and showed signs of cytoplasmic damage leading to d esintegration. The mesangial cells contained few dipid droplets and th e matrix was normal. The arterioles were not involved. The lesion sugg ests an impairment of the clearance of lipids, leading to interstitial accumulation and cellular damage.