Madhavan Sengodi, Prickett Timothy C R, Espiner Eric A, Barrell Graham K
Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 84, Lincoln 7647, Christchurch, New Zealand.
Department of Medicine, University of Otago, PO Box 4345, Christchurch 8140, New Zealand.
Reprod Fertil Dev. 2017 Mar;29(3):575-584. doi: 10.1071/RD15192.
C-type natriuretic peptide (CNP), a paracrine growth factor promoting vasodilation and angiogenesis, is upregulated in human and ovine pregnancy in response to vascular stress or nutrient restriction (NR) in late gestation. Postulating that maternal plasma CNP products are increased by modest NR (50% of metabolisable energy requirement) early in pregnancy, and further enhanced by litter size, we studied serial changes of maternal plasma CNP in pregnant ewes receiving a normal (NC, n=12) or restricted (NR, n=13) diet from Day 30 to Day 93 or 94 of gestation. Liveweight of NR ewes was 10kg less than that of NC ewes at slaughter. Plasma CNP products increased progressively after Day 40 and were higher in NR (P<0.05) ewes after Day 60; they were also enhanced by litter size (P<0.01) and were positively associated with increased placental efficiency. In contrast, whereas fetal and placental weight were reduced by NR, fetal plasma CNP products (Day 93/94) were not affected. We conclude that increases in CNP during rapid placental growth are further enhanced by both increasing nutrient demands and by reduced supply, presumably as part of an adaptive response benefitting placental-fetal exchange.
C型利钠肽（CNP）是一种促进血管舒张和血管生成的旁分泌生长因子，在人类和绵羊妊娠后期，响应于血管应激或营养限制（NR）而上调。假设妊娠早期适度的营养限制（可代谢能量需求的50%）会增加母体血浆CNP产物，且产仔数会进一步增强这种作用，我们研究了从妊娠第30天到第93或94天接受正常（NC，n = 12）或限制（NR，n = 13）饮食的怀孕母羊母体血浆CNP的系列变化。屠宰时，NR母羊的体重比NC母羊轻10千克。血浆CNP产物在第40天后逐渐增加，第60天后在NR母羊中更高（P<0.05）；它们也因产仔数而增加（P<0.01），并与胎盘效率的提高呈正相关。相比之下，虽然NR会降低胎儿和胎盘的重量，但胎儿血浆CNP产物（第93/94天）不受影响。我们得出结论，在胎盘快速生长期间，CNP的增加会因营养需求增加和供应减少而进一步增强，这可能是有利于胎盘-胎儿交换的适应性反应的一部分。
