ACTH is a segment of a much larger glycoprotein prohormone molecule called proopiomelanocortin (POMC). POMC is synthesized by the corticotrophs of the anterior pituitary, which constitute about 10 percent of the gland.
Caviar harvested from an older fish is the more rare, and more sought after, white caviar. The Beluga sturgeon are primarily found in the Caspian Sea, which is surrounded by Iran, Azerbaijan, Russia, Kazakhstan and Turkmenistan. The other primary source of Beluga sturgeon is the Black Sea near Russia and Romania.
Caviar is the processed roe--eggs--of any of several large fish. But the sturgeon produces the top of the line. Beluga sturgeon heads the list for quality, flavor and popularity, according to Rob Brickley, market representative for Lieber Foods Inc., a wholesale house in Atlanta that distributes caviar.