Maternal metabolizable protein restriction during gestation affects the vascular function of maternal and fetal placental arteries in sheep

Leslie A Lekatz; Praveen Shukla; Stephen T O'Rourke; Christopher S Schauer; Megan L Van Emon; Kasey R Maddock-Carlin; Kimberly A Vonnahme

doi:10.1016/j.theriogenology.2022.03.016

Maternal metabolizable protein restriction during gestation affects the vascular function of maternal and fetal placental arteries in sheep

Theriogenology. 2022 Jun:185:24-33. doi: 10.1016/j.theriogenology.2022.03.016. Epub 2022 Mar 24.

Authors

Leslie A Lekatz¹, Praveen Shukla², Stephen T O'Rourke², Christopher S Schauer³, Megan L Van Emon³, Kasey R Maddock-Carlin⁴, Kimberly A Vonnahme⁴

Affiliations

¹ Department of Animal Sciences, North Dakota State University, Fargo, ND, 58108, USA. Electronic address: Lalekatz@crk.umn.edu.
² Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, 58108, USA.
³ Hettinger Research Extension Center, North Dakota State University, Hettinger, ND, 58639, USA.
⁴ Department of Animal Sciences, North Dakota State University, Fargo, ND, 58108, USA.

PMID: 35367778
DOI: 10.1016/j.theriogenology.2022.03.016

Abstract

We hypothesized isocaloric diets low in protein would decrease the sensitivity of caruncular (CAR) and cotyledonary (COT) arteries compared to placental arteries from ewes receiving adequate metabolizable protein (MP) requirements. Pregnant ewes were fed one of three isocaloric dietary treatments that provided 60% (MP60), 80% (MP80), or 100% (MP100) of the MP requirements. Diets were fed from day 100-130 of gestation. In vitro dose response curves to bradykinin (BK), sodium nitroprusside (SNP), potassium chloride (KCl), and phenylephrine (PE) in CAR and COT arteries were performed. As MP decreased, the sensitivity to a low dose of KCl increased (P = 0.05) in the COT arteries. There was an overall treatment effect in the CAR and COT arteries for the BK dose response curve, where CAR arteries of MP80 ewes were more sensitive (P = 0.05) to BK compared with MP60 and MP100 ewes, and COT arteries of MP60 and MP80 ewes were more sensitive (P = 0.01) to BK compared with MP100 ewes. There were no treatment effects (P ≥ 0.09) on the SNP or PE dose response curves in CAR or COT arteries. The mechanism of the BK induced vasodilation needs to be elucidated. Moreover, MP restriction appears to alter placental vascular function, which could help explain the differences in nutrient flux previously reported.

Keywords: Bradykinin; Endothelium; Ewes; Placenta; Pregnancy; Vasoactivity.

MeSH terms

Animal Nutritional Physiological Phenomena* / physiology
Animals
Arteries
Diet, Protein-Restricted / veterinary
Female
Organ Size
Placenta* / metabolism
Pregnancy
Sheep