**4.1 Cytochrome P-450scc**

The cytochrome P-450scc side chain cleavage is an enzyme present in the inner mitochondrial membranes. The enzyme is involved in three catalytic cycles on the cholesterol molecule: the introduction of hydroxyl groups at positions C-22 and C-20, and the subsequent scission of the side chain between these carbons. ACTH and LH stimulate cytochrome P-450scc synthesis in a mechanism that depends on cAMP synthesis as a second messenger (Auchus & Miller, 2000; Straus & Hsue, 2000).
