Pituitary extracts have been known for nearly 50 years to contain fat-mobilizing or lipolytic activity. Now that pituitary hormones have been isolated and their primary structures are known, it is possible to conclude that somatotropin, thyrotropin, corticotropin (ACTH), and melanotropins (α- and β-MSH) are active as lipolytic agents. A new pituitary lipolytic factor, β-lipotropin (β-LPH), whose chemical characteristics are completely different from known pituitary hormones, was discovered in 1964 during the course of improving the procedure for the isolation of ACTH from sheep pituitary glands (Li, 1964; Birk and Li, 1964). β-Lipotropin has subsequently been isolated from pituitary glands of cow, pig, rat, whale, turkey, and ostrich (Li, 1982; Naudé and Oelofsewn, 1981). The complete amino acid sequences of human, sheep, pig, cow and ostrich (see Fig. 1) have been proposed (Li, 1982; Naudé et al., 1981). β-Lipotropin is the prohormone for β-MSH and β-endorphin (β-EP). It is initially biosynthesized in a large precursor, proopiome-lanocortin (POMC), which is also the precursor for ACTH (Mains et al., 1977; Nankanishi et al., 1979).
KeywordsPituitary Gland Lipolytic Activity Complete Amino Acid Sequence Peptide Protein Aldosterone Production
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