Effects of systemic progesterone during the early luteal phase on the availabilities of amino acids and glucose in the bovine uterine lumen

Abstract

Abstract. The uterine histotroph provides essential nutrition to the developing conceptus during the preimplantation period of pregnancy. The objective of the present study was to examine the effects of cycle stage and progesterone (P4) concentrations in the blood on the recoverable quantities of amino acids and glucose in the histotroph during the preimplantaion period of conceptus development. Following oestrus, dairy heifers were assigned to low, control or high P4 groups (n ¼ 6 heifers per treatment and time point). The uterine horn ipsilateral to the corpus luteum was flushed on either Day 7 or Day 13. The present study quantified 24 amino acids and glucose in the uterine flushings using HPLC and fluorometry, respectively. Heifers in the low P4 group had lower plasma concentrations of P4 throughout the cycle, whereas heifers in the high group had higher plasma concentrations of P4 between Days 3 and 7 compared with the control group (P , 0.05). Total recoverable neutral (Ser, Gln, Gly, Thr, Cit, b-Ala, Tau, Ala, Tyr, Trp, Met, Val, Phe, Ile, Leu, Pro and Cys), acidic (Glu) and basic (His, Arg, Orn and Lys) amino acids were greater (P , 0.05) on Day 13 than on Day 7. There was no significant difference in the amount of Asp or Asn between Day 7 and Day 13. The amount of amino acids recovered on Day 7 was similar across treatment groups. On Day 13, the amount of Asn, His and Thr was lower (P , 0.05) in the low P4 heifers compared with the controls and/or high P4 heifers. Quantities of glucose were not altered by cycle stage or P4 treatment. In conclusion, the stage of oestrous cycle and P4 play important roles in modulating amino acids in the histotroph, a potentially critical factor for early embryonic and/or conceptus survival.

Amino Acids in the Uterine Luminal Fluid Reflects the Temporal Changes in Transporter Expression in the Endometrium and Conceptus during Early Pregnancy in Cattle

“…Conversely, in heifers with a delay in the post-ovulatory increase in P4 (associated with smaller conceptuses), expression of SLC43A2 , SLC6A14 , SLC7A6 and SLC7A7 for amino acid transport into the ULF was sub-optimal. These P4-regulated changes in expression of the transporters in the endometrium are consistent with lower concentrations of histidine and asparagine in ULF of low P4 heifers on Day 13 [37]. Therefore, in vivo manipulation of P4 alters the expression of genes for amino acid transporter from the endometrium into the ULF which has clear consequences for conceptus elongation in vivo which supports findings from studies with ewes [38].…”

Dose frequency of prostaglandin F2α administration to dairy cows exposed to presynchronization and either 5- or 7-day Ovsynch program durations: Ovulatory and luteolytic risks

“…These observations are consistent with greater progesterone concentration in cows of the present study that had an original CL plus new CL for both luteal regression and greater P/AI compared with cows with lower progesterone before PGF 2α and likely poorer complete luteal regression and poorer P/AI (Table 5; Stevenson, 2016). Furthermore, elevated progesterone during the period of follicular development before PGF 2α -induced luteolysis is critical to uterine function because the stage of the estrous cycle and progesterone play important roles in modulating AA in the histotroph, a potentially critical factor for early embryonic or conceptus survival (Mullen et al, 2014).…”

Global proteomic characterization of uterine histotroph recovered from beef heifers yielding good quality and degenerate day 7 embryos

“…The protein components of the histotroph are important for conceptus-maternal interaction, specifically the processes of elongation of the trophoblast, recognition of pregnancy, implantation, and placentation [12,13]. Many components of the histotroph are secreted under the influence of progesterone and in the early luteal phase [14,15] also by oestradiol [16] The objective of this study was to analyse the proteomic composition of uterine flushes of inseminated beef heifers with normal and degenerate embryos on Day 7 post insemination in order to elucidate what potential proteins are present in the uterus to support the embryo until blastocyst development. Our hypothesis is that there will be differences in composition between the animals with different types of embryos.…”