HYPERTRIGLYCERIDEMIC SERUM FROM MAGNESIUM-DEFICIENT RATS INDUCES PROLIFERATION AND LIPID-ACCUMULATION IN CULTURED VASCULAR SMOOTH-MUSCLE CELLS

An important characteristic of hyperlipemia associated with magnesium deficiency in rats is the postprandial accumulation of triglyceride-ri ch lipoproteins. The present investigation was performed to determine the effect of serum from magaesium-deficient animals on cultured vascu lar smooth muscle cells (VSMC). Sera were obtained from control and ma gnesium-deficient rats fed adequate or deficient diets for 8 days. Mag nesium-deficient animals were hypertriglyceridemic compared with contr ol rats, but their total cholesterolemia was not significantly modifie d pooled sera from control and magnesium-deficient animals were added to the culture medium at various concentrations. The maximum of prolif eration for both control and magnesium-deficient sera was reached when they were added at 6% to the culture medium and on day 4 after the be gining of incubation. Medium containing serum from magnesium-deficient rats stimulated the cell proliferation as monitored by cell count and [H-3]thymidine incorporation Staining of VSMC with Oil red O and meas uring lipids have shown a marked lipid accumulation (triglycerides) in cells incubated with serum obtained from magnesium-deficient animals compared with serum from control rats. These results indicate that ser um from magnesium-deficient rats contains factors that stimulate proli feration of arterial medial cells and that hyperlipemia associated wit h magnesium-deficiency may cause lipid accumulation in vascular cells.