Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/31/1999
Publication Date: N/A
Technical Abstract: Leptin is a multifunctional protein produced in various tissues including the placenta. The current study was conducted to examine breed and uterine environment effects on porcine placental leptin and leptin receptor messenger ribonucleic acid (mRNA) expression. Placental samples were taken on gestational day (gd) 75 from either Meishan (M, n=10) or white crossbred d(WC, n=8) gilts. All gilts had undergone unilateral surgical uterine ligation on gd 2-6 of pregnancy to produce crowded (C, <20cm/potential embryo) and roomy (R, >25cm/potential embryo) uterine environments. Expression of both placental leptin (0.99+/0.10 vs 0.50+/0.11, P=0.004) and leptin receptor (1.18+/0.19 vs. 0.61+/0.15, P=0.04) mRNA was greater in M than WC, but placental insulin-like growth factor 1 mRNA expression did not differ between breeds. There was no difference in gene expression between C and R environments. A strong positive correlation between leptin and leptin receptor mRNA expression was observed across treatments and breeds (R=0.74, P=0.004). Meishan placentae have been shown to be more vascular than Yorkshire placentae (Biol. Reprod. 58:905-910, 1998). Recently leptin has been shown to induce angiogenesis both in vitro and in vivo (Science 281:1683, 1998). High levels of leptin expression seen in Meishan placentae may be indicative of an angiogenic role of placental leptin.