Disease relevance of LOC443319

• The ovine (o) PL gene is expressed in chorionic binucleate cells (oBNC) and cis-elements located within the proximal promoter (-124 to +16 bp) are capable of trophoblast-specific expression in human (BeWo) and rat (Rcho-1) choriocarcinoma cells [1].
• Fetuses from restricted mothers had higher peak GH concentrations after a GRF challenge (P < 0.001), but after correction The specific binding of [125I]ovine placental lactogen ([125I]oPL) or [125I]oGH to maternal or fetal hepatic microsomal membrane preparations was not changed by the maternal undernutrition [2].
• The maternal infusion of HDL at doses of 302-784 mg (5.3-13.8 mg/kg body weight) stimulated significant increases in maternal plasma PL concentrations in six out of eight experiments (six ewes), and the infusion of 108-264 mg (1.9-4.6 mg/kg) stimulated plasma PL concentrations in two out of six experiments [3].
• The appearance of nuclease hypersensitivity during pregnancy correlates with rising levels of placental lactogen which suggests that this hormone may be the stimulus for expression during the first stage of lactogenesis [4].
• Relations between maternal and fetal plasma concentrations of placental lactogen and placental and fetal weights in well-fed ewes [5].

High impact information on LOC443319

• Recent findings from this laboratory suggest that the biological actions of placental lactogen (PL) in mammalian fetal tissues are mediated through binding of the hormone to a distinct and unique PL receptor [6].
• Purification of a distinct placental lactogen receptor, a new member of the growth hormone/prolactin receptor family [6].
• Soluble extracts containing specific, high-affinity (Kd 0.5 nM) PL binding activity were prepared by incubating ovine fetal and maternal liver microsomes with 1% Triton X-100 [6].
• Puralpha, a single-stranded deoxyribonucleic acid binding protein, augments placental lactogen gene transcription [1].
• Ovine placental lactogen is as reactive as human growth hormone with the human growth hormone receptor of cultured human (IM-9) lymphocytes, which confirms the findings of Carr and Friesen with receptors of human liver [7].

Chemical compound and disease context of LOC443319

• Evaluation of progesterone, estrogens and placental lactogen in pregnant ewes following experimental infection with an abortive agent chlamydia psittaci "Var-Ovis" [8].
• The plasma levels of progesterone, free and conjugated estrone and of placental lactogen have been determined in three groups of pregnant ewes inoculated with an abortive agent (Chlamydia psittacci var. ovis) on day 66 of gestation [8].

Biological context of LOC443319

• Quantification and cellular localization of ovine placental lactogen messenger ribonucleic acid expression during mid- and late gestation [9].
• A unique placental lactogen receptor: implications for fetal growth [10].
• Evolution of prolactin and placental lactogen receptors in ewes during pregnancy and lactation [11].
• Distribution of binding sites for ovine placental lactogen in the sheep [12].
• From a single cell fusion, five stable hybridomas secreting antiovine placental lactogen (oPL) antibodies were obtained [13].

Anatomical context of LOC443319

• Placental lactogen-binding sites in isolated fetal fibroblasts: characterization, processing, and regulation [14].
• To examine the relative roles of placental lactogen (PL) and GH in fetal metabolism, we have examined the effects of ovine PL (oPL), ovine GH (oGH), and ovine PRL (oPRL) on glycogen metabolism in cultured ovine fetal hepatocytes and have examined the binding of these hormones to hepatic membranes from fetal and neonatal lambs [15].
• The ewes were then killed, and the binding of [125I]ovine (o) PL to hepatic microsomes from the fetal lambs was examined [16].
• Placental lactogen (PL) stimulates amino acid transport, DNA synthesis, and insulin-like growth factor production in isolated fetal fibroblasts and myoblasts [14].
• Effects of recombinant ovine interferon tau, placental lactogen, and growth hormone on the ovine uterus [17].

Associations of LOC443319 with chemical compounds

• The placental lactogen receptor in maternal and fetal sheep liver: regulation by glucose and role in the pathogenesis of fasting during pregnancy [18].
• Stimulation of ovine placental lactogen secretion by arginine infusion [19].
• Specific binding of PL was 1.5- to 5-fold higher in cells preincubated in medium containing dexamethasone (0.1 microM), suggesting that glucocorticoids may regulate expression of the fetal PL receptor [14].
• Purification and partial characterization of the cyanogen bromide fragments of ovine placental lactogen [20].
• The sequential, overlapping actions of progesterone, IFNtau, placental lactogen (PL), and growth hormone (GH) comprise a hormonal servomechanism that regulates endometrial gland morphogenesis and terminal differentiated function during gestation [21].

Physical interactions of LOC443319

• Ovine placental lactogen is known to bind to prolactin receptors and to initiate milk synthesis in the rabbit mammary gland [22].

Other interactions of LOC443319

• Ovine placental lactogen is a potent somatogen in the growth hormone (GH)-deficient rat: comparison of somatogenic activity with bovine GH [23].
• However, the levels of GHR expression are markedly lower in fetal hepatic tissue compared to postnatal values, and there are conflicting data suggesting that ovine placental lactogen (oPL) and oGH share a common receptor [24].
• Ovine placental lactogen was very efficient in provoking the accumulation of beta-casein mRNA in rabbit mammary explants but was much less active on ewe mammary explants [22].
• Treatment with bovine growth hormone increased circulating concentrations of growth hormone, insulin-like growth factor-I, and nonesterified fatty acids and decreased urea concentrations relative to those in ewes treated with ovine placental lactogen or saline [25].

Analytical, diagnostic and therapeutic context of LOC443319

• The detergent solubilized PL receptor was purified two- to threefold by ion-exchange chromatography and an additional twofold by gel exclusion chromatography on Sepharose 6B [6].
• The PL receptor was then purified 75,000- to 125,000-fold by affinity chromatography using a column of ovine PL (oPL) coupled to Affi-Gel 10 [6].
• Immunogold localization of placental lactogen and the SBU-3 antigen by cryoultramicrotomy at implantation in the sheep [26].
• Maternal and fetal concentrations of ovine placental lactogen measured by radioimmunoassay [27].
• Ovine placental lactogen-induced heterodimerization of ovine growth hormone and prolactin receptors in living cells is demonstrated by fluorescence resonance energy transfer microscopy and leads to prolonged phosphorylation of signal transducer and activator of transcription (STAT)1 and STAT3 [28].

References