Conversion of Beta Sitosterol to Cholesterol Blocked in an Insect by Hypocholesterolemic Agents
J. A. Svoboda 1 and
W. E. Robbins 1
1 Entomology Research Division, U.S. Department of Agriculture, Beltsville, Maryland 20705
Two vertebrate hypocholesterolemic agents (triparanol and 22,25-diazacholesterol) block the conversion of
-sitosterol to cholesterol in the larva of the tobacco hornworm, Manduca sexta (Johannson). A primary site of inhibitory action is the terminal step in this conversionthe reduction of desmosterol (24-dehydrocholesterol) to cholesterol. This is also the site at which these compounds inhibit de novo cholesterol biosynthesis in higher animals. Both agents severely inhibit growth and maturation of the tobacco hornworm.