title: Leptin in the bovine corpus luteum: receptor expression and effects on progesterone production.
abstract: In cattle, leptin has been implicated in the control of ovarian function and has been shown to modulate steroid production by theca and granulosa cells in a number of species. However, a direct effect of leptin on bovine luteal function has not been demonstrated. This study was conducted to determine if the leptin receptor (OB-R) is expressed in the bovine corpus luteum (CL), and to examine the effects of leptin on progesterone production by dispersed luteal cells in vitro. RT-PCR was used to detect the presence of OB-R and, more specifically, the long, biologically active isoform (OB-Rb), in CL, collected on days 2-18 of the oestrous cycle (n=18). The effects of leptin on progesterone production were investigated in dispersed luteal cells prepared from CL collected on days 5 and 8 (n=14) of the cycle. The dispersed luteal cells were cultured for 24 hr with recombinant human leptin and/or LR3-IGF-1 and/or LH. OB-Rs, in particular, OB-Rb, were expressed in the CL at all stages of development. Progesterone production by luteal cells was increased (P<0.001) by treatment with LH (10 ng/ml) but treatment with leptin alone had no effect. However, in the presence of IGF-1 (100 ng/ml), leptin (10 ng/ml) caused a significant (P<0.005) increase in progesterone production. In conclusion, we have shown that the leptin receptor is expressed in the bovine CL and have demonstrated a modulatory effect of leptin on luteal progesterone production in vitro.
authors.affiliation: School of Biosciences, The University of Nottingham, Sutton Bonington, United Kingdom.
authors.forename: L T
authors.initials: LT
authors.lastname: Nicklin
authors.forename: R S
authors.initials: RS
authors.lastname: Robinson
authors.forename: P
authors.initials: P
authors.lastname: Marsters
authors.forename: B K
authors.initials: BK
authors.lastname: Campbell
authors.forename: G E
authors.initials: GE
authors.lastname: Mann
authors.forename: M G
authors.initials: MG
authors.lastname: Hunter
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics*; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D020738:Leptin / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism; D008184:Luteal Cells / Q000187:drug effects / Q000378:metabolism; D011374:Progesterone / Q000096:biosynthesis*; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D054411:Receptors, Leptin
chemical_list: C515448:LEPR protein, human; D020738:Leptin; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D011374:Progesterone