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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #318335
Title: Ovine maternal nutrient restriction from mid to late gestation decreases heptic progesterone inactivating enzyme activity

Author
item GILFEATHER, CHRISTA - Mississippi State University
item HART, CAITLIN - Mississippi State University
item VONNAHME, KIMBERLY - North Dakota State University
item LEMLEY, CALEB - Mississippi State University

Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 12/3/2014
Publication Date: N/A
Citation: N/A

Interpretive Summary: In the pregnant ewe, maternal nutrient restriction increases circulating concentrations of progesterone. This increase in progesterone is due to a decrease in hepatic progesterone inactivating enzyme activity and liver weight. Development of therapeutics to target steroid metabolism during compromised pregnancies could reduce the risk of intrauterine growth restriction during maternal nutrient restriction.

Technical Abstract: Previously we have shown increased concentrations of progesterone and decreased liver weight in mid to late pregnant ewes provided a nutrient restricted vs. adequate diet. This alteration in peripheral progesterone could be due to increased synthesis and/or decreased clearance of progesterone. Therefore, the objective was to examine hepatic and placental progesterone inactivating enzymes in a mid to late gestation ovine model of intrauterine growth restriction. Ewes (n = 30) were allocated to receive either 100% [adequate (ADQ; n = 14)] or 60% [restricted (RES; n = 16)] of nutrient requirements until day 130 of gestation. At slaughter both maternal and fetal livers and maternal (caruncle) and fetal (cotyledon) placentas were collected for enzyme analysis. Activity of aldo-keto reductase 1C (AKR1C) and uridine 5’-diphospho-glucurosyltransferase (UGT) were determined using specific enzyme substrates. Activities were expressed relative to mg of protein, total tissue weight, or body weight. Data were analyzed using MIXED procedure of SAS and the model statement included nutritional plane. Activity of AKR1C in the caruncle (P > 0.60) and cotyledon (P > 0.30) were not different between RES vs. ADQ fed. Activity of UGT was not detected in the caruncle or cotyledon. Activity of AKR1C in the maternal liver was not different (P = 0.89) when expressed relative to mg of protein. However, activity of AKR1C in the maternal liver was decreased (P < 0.05) in RES vs. ADQ fed when expressed relative to total liver or maternal body weight. Activity of AKR1C in the fetal liver was not different (P > 0.35) when expressed relative to mg of protein, total liver, or fetal body weight. Activity of UGT in the maternal and fetal liver were not different (P > 0.05) when expressed relative to mg of protein, total liver, or maternal body weight. In general enzyme activity was increased in maternal vs. fetal tissues. In conclusion, nutrient restricted dams had decreased hepatic progesterone inactivating enzyme activity, which may be responsible for the previously observed increase in peripheral concentrations of progesterone. Moreover, concomitant changes occurred in AKR1C activity and liver weight, which deserves future investigation.