Cholesterogenesis: Derepression in extrahepatic tissues with 4-aminopyrazolo[3,4-d]pyrimidine

Administration of 4-aminopyrazolo[3,4-d]pyrimidine decreased serum cholesterol levels in the rat to less than 5 milligrams per deciliter. Coincident with this change, there was a 2.1- to 16.0-fold increase in the rate of sterol synthesis in seven extrahepatic tissues. This suggests that cholesterol carried in serum lipoproteins plays a major role in regulating sterol synthesis in many extrahepatic tissues.