Effects of nicotinic acid on serum and tissue cholesterol in rabbits.

SERUM cholesterol is lowered by oral nicotinic acid in the human and in the rabbit. ' The fall in serum cholesterol is roughly proportional to the initial elevation and the amount of nicotinic acid required to produce striking changes in the serum is rather large. These observations pertaining to serum cholesterol assume more importance if they are accompanied by changes in tissue cholesterol. The purpose of this study was to determine: (1) if the lowered serum cholesterol was accompanied by lowered tissue cholesterol in the aorta and (2) if the nicotinic acid lowered serum cholesterol by causing deposition of cholesterol in the liver.