Effect of nicotinic acid on the incorporation of radiocarbon into cholesterol.

FOLLOWING the lead of Altschul, 1 a number of investigators have established that nicotinic acid depresses the serum cholesterol. A previous report indicated that inclusion of nieotinic acid in experimental diets fed to rabbits partially prevented the anticipated rise in serum cholesterol, prevented cholesterol deposition in the aorta and, to a lesser extent, cholesterol deposits in the liver. I t was emphasized that the mechanism whereby nicotinic acid altered serum and tissue cholesterol was unknown. It was pointed out, however, that the large number of methyl groups required for the excretion of nicotinic acid might alter cholesterol synthesis.