Insulin-like growth factor binding proteins (IGFBPs) were characterized in @entity291 anterior pituitary tissue, pituitary conditioned media, and serum collected during the preovulatory and early luteal phases of the estrous cycle. Effects of in vitro treatments of pituitaries with luteinizing hormone-releasing hormone (LHRH), @entity53 , and @entity1420 on IGFBP secretion were also evaluated. Predominant IGFBPs detected in anterior pituitary tissue by immunoprecipitation, ligand blotting, and Northern blotting were @entity34128 (29 kDa), @entity21904 (32 kDa), and @entity37644 (36 and 39 kDa doublet). Conditioned culture media contained @entity34128 , a slightly larger form of @entity21904 (33 kDa), the 36- and 39-kDa forms of @entity37644 , and a more extensively glycosylated form of @entity37644 (44 kDa). In serum, @entity34128 was not readily detected, and @entity37644 (40- and 44-kDa doublet) and @entity21904 (34 kDa) were larger than in pituitary tissue. Levels of @entity70016 in pituitary tissue decreased during the preovulatory period and were lowest in the early luteal phase. Treatment with LHRH increased @entity21904 levels in media twofold. @entity53 or @entity1420 did not alter IGFBP secretion in vitro. Predominant IGFBPs produced and released by anterior pituitary tissue were @entity21904 . The activity of IGFBPs fluctuates in the pituitary in association with changes in stage of estrous cycle, implicating IGFBPs as potential regulators of gonadotrope function.

Insulin-like growth factor binding proteins in the XXXX anterior pituitary.

@entity1420 :: ('MESH:D011374', 'Chemical') :: ['progesterone'] @entity53 :: ('MESH:D004958', 'Chemical') :: ['Estradiol', 'estradiol'] @entity21904 :: ('282260(Tax:9913)', 'Gene') :: ['IGFBP-2, -3 and -5', 'IGFBP-2'] @entity37644 :: ('282261(Tax:9913)', 'Gene') :: ['IGFBP-3'] @entity291 :: ('9913', 'Species') :: ['bovine'] @entity70016 :: ('282260;282261;404185', 'Gene') :: ['IGFBP-2, -3, and -5'] @entity34128 :: ('404185(Tax:9913)', 'Gene') :: ['IGFBP-5']
@entity291 :: (9913,Species) :: ['bovine']
