title: Luteinizing hormone receptor number and affinity in corpora lutea from prepuberal gilts induced to ovulate and spontaneous corpora lutea of mature gilts.
abstract: This study was designed to determine if luteal cell receptors for luteinizing hormone/human chorionic gonadotropin (LH/hCG) contribute to the previously demonstrated abnormal function of induced corpora lutea (CL) in gilts. Twenty-five prepuberal (P) gilts, induced to ovulate with 1,500 IU pregnant mare serum gonadotropin followed 72 h later with 500 IU hCG (d 0 = day of hCG), and 22 mature (M) gilts that had displayed two or more estrous cycles were ovariectomized (OVX) on d 10, 14, 18, 22 or 26 after the onset of estrus. All gilts except those OVX on d 10 were hysterectomized between d 6 and 9 to ensure luteal maintenance. The CL were stored at -196 degrees C until determination of LH/hCG receptor number and dissociation constant (KD) by saturation analysis. Receptor number was greater for M than for P gilts on d 14 (P less than .07) and d 18 (P less than .01). The KD was greater in M than in P gilts on d 14 (P less than .01) and d 18 (P less than .0001). The LH/hCG receptor number and KD of P gilts remained the same throughout the days studied. The LH/hCG receptor number (fmol/mg protein) of M gilts was elevated on d 10, 14, and 18 (50.8, 50.4 and 51.4, respectively) and decreased on d 22 (26.5) and d 26 (25.4) to values similar to those of P gilts. In M gilts, KD increased on d 14, remained high on d 18 and decreased on d 22. We suggest that abnormal function of induced CL in P gilts may be due to an elevated LH receptor number.
authors: Dept. of Anim. and Dairy Sci., University of Georgia, Athens 30602.
authors: C E
authors: CE
authors: Estienne
authors: G B
authors: GB
authors: Rampacek
authors: R R
authors: RR
authors: Kraeling
authors: M J
authors: MJ
authors: Estienne
authors: C R
authors: CR
authors: Barb
mesh_terms: D000818:Animals; D003338:Corpus Luteum / Q000032:analysis / Q000502:physiology*; D005260:Female; D010062:Ovulation Induction / Q000662:veterinary*; D011974:Receptors, LH / Q000032:analysis / Q000502:physiology*; D012741:Sexual Maturation; D013552:Swine / Q000502:physiology*
chemical_list: D011974:Receptors, LH