Effects of maternal undernutrition on the growth, development and antioxidant status of ovine placentome subtypes during late pregnancy.

This study investigated the effects of maternal undernutrition on the growth, development and antioxidant status of ovine placentome subtypes during late pregnancy. Eighteen time-mated Mongolian ewes with singleton fetuses were allocated to three groups at d 90 of pregnancy: Restricted Group 1 (RG1, 0.18 MJ ME · kg BW-0.75 · d-1, n = 6), Restricted Group 2 (RG2, 0.33 MJ ME · kg BW-0.75 · d-1, n = 6) and Control Group (CG, ad libitum, 0.67 MJ ME · kg BW -0.75 · d -1, n = 6). All animals were supplied chopped hay during the restriction period. At 140 days of pregnancy, the gravid uterus was removed; then individual fetuses and placentae were weighed. The numbers and weight of the placentome subtypes were examined. The number of vessels of the placentome subtypes were observed in sections stained with hematoxylin-eosin. The indexes of antioxidant capacity and oxidative stress, including total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity and mal-ondialdehyde (MDA) concentration, were measured by spectrometric kits. The fetal weights, placental weights and the numbers of Type A placentomes in both restricted groups were reduced (P .05); however, the number of vessels and MDA concentration of Type C and Type D placentome were higher than those of the Type A and Type B (P < .05). These results indicate that the growth and development of ovine Type A placentome was altered during late pregnancy. More and more Type B, Type C and Type D were formed from the Type A associated with maternal undernutrition. Oxidative stress occurred in all types of placentomes for the RG1 group, and the more flattening placentomes that were converted, the worse the antioxidant/pro-oxidant imbalance that was induced.