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 an expensive delicacy consisting of the unfertilized eggs (roe) of sturgeon brined with a salt solution. Classic caviar comes primarily from Iran or Russia, harvested by commercial fishermen working in the Caspian Sea. A specific species of sturgeon called beluga provide what many consider to be the best in the world.