title: Effect of melatonin or maternal nutrient restriction on vascularity and cell proliferation in the ovine placenta.
abstract: Previously we reported increased umbilical artery blood flow in ewes supplemented with melatonin from mid- to late-pregnancy, while maternal nutrient restriction decreased uterine artery blood flow. To further unravel these responses, this study was designed to assess placental cell proliferation and vascularity following supplementation with melatonin or maternal nutrient restriction. For the first experiment, 31 primiparous ewes were supplemented with 5mg of melatonin per day (MEL) or no melatonin (CON) and allocated to receive 100% (adequate fed; ADQ) or 60% (restricted; RES) of their nutrient requirements from day 50 to 130 of gestation. To examine melatonin receptor dependent effects, a second experiment was designed utilizing 14 primiparous ewes infused with vehicle, melatonin, or luzindole (melatonin receptor 1 and 2 antagonist) from day 62 to 90 of gestation. For experiment 1, caruncle concentrations of RNA were increased in MEL-RES compared to CON-RES. Caruncle capillary area density and average capillary cross-sectional area were decreased in MEL-RES compared to CON-RES. Cotyledon vascularity was not different across dietary treatments. For experiment 2, placental cellular proliferation and vascularity were not affected by infusion treatment. In summary, melatonin interacted with nutrient restriction to alter caruncle vascularity and RNA concentrations during late pregnancy. Although melatonin receptor antagonism alters feto-placental blood flow, these receptor dependent responses were not observed in placental vascularity. Moreover, placental vascularity measures do not fully explain the alterations in uteroplacental blood flow.
authors.affiliation: Animal and Nutritional Sciences, West Virginia University, Morgantown, WV 26506, United States.
authors.forename: Adam W
authors.initials: AW
authors.lastname: Eifert
authors.affiliation: Animal and Nutritional Sciences, West Virginia University, Morgantown, WV 26506, United States.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Wilson
authors.affiliation: Animal Sciences, North Dakota State University, Fargo, ND 58108, United States.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Vonnahme
authors.affiliation: Animal Sciences, North Dakota State University, Fargo, ND 58108, United States.
authors.forename: Leticia E
authors.initials: LE
authors.lastname: Camacho
authors.affiliation: Animal Sciences, North Dakota State University, Fargo, ND 58108, United States; Advanced Imaging and Microscopy Core Lab North Dakota State University, Fargo, ND 58108, United States.
authors.forename: Pawel P
authors.initials: PP
authors.lastname: Borowicz
authors.affiliation: Animal Sciences, North Dakota State University, Fargo, ND 58108, United States; Advanced Imaging and Microscopy Core Lab North Dakota State University, Fargo, ND 58108, United States.
authors.forename: Dale A
authors.initials: DA
authors.lastname: Redmer
authors.affiliation: Animal Sciences, North Dakota State University, Fargo, ND 58108, United States.
authors.forename: Sinibaldo
authors.initials: S
authors.lastname: Romero
authors.affiliation: Animal Sciences, North Dakota State University, Fargo, ND 58108, United States.
authors.forename: Sheri
authors.initials: S
authors.lastname: Dorsam
authors.affiliation: Animal Sciences, North Dakota State University, Fargo, ND 58108, United States.
authors.forename: Jodie
authors.initials: J
authors.lastname: Haring
authors.affiliation: Animal and Dairy Sciences, Mississippi State University, MS 39762, United States. Electronic address: clemley@ads.msstate.edu.
authors.forename: Caleb O
authors.initials: CO
authors.lastname: Lemley
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001808:Blood Vessels / Q000166:cytology / Q000187:drug effects; D031204:Caloric Restriction / Q000662:veterinary; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D006727:Hormone Antagonists / Q000494:pharmacology; D039382:Maternal Nutritional Physiological Phenomena; D008550:Melatonin / Q000494:pharmacology*; D010920:Placenta / Q000098:blood supply* / Q000166:cytology* / Q000187:drug effects; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects; D044094:Receptors, Melatonin / Q000037:antagonists & inhibitors; D012756:Sheep / Q000502:physiology*
chemical_list: D006727:Hormone Antagonists; D044094:Receptors, Melatonin; D008550:Melatonin
keywords: Blood flow; Capillary; Developmental programming; Melatonin; Pregnancy