Isoleucine requirement of pregnant sows1

Franco, Danilo; Josephson, Jessica K; Moehn, Soenke; Pencharz, Paul B.; Ball, Ronald O.

doi:10.2527/jas.2012-6174

Cited by 12 publications

(7 citation statements)

References 14 publications

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“…In the second study, we determined mean lysine requirements comparing the same 2 distinct phases of pregnancy, and found the requirements in early and late pregnancy to be 36. Earlier studies in pregnant pigs showed similar results, with late pregnancy resulting in higher requirements for threonine (31), lysine (32), isoleucine (33), and tryptophan (34), although proportional increases varied from 35% to 63% among all these amino acids.…”

Section: Discussionsupporting

confidence: 62%

Dietary phenylalanine requirements during early and late gestation in healthy pregnant women

Ennis

Rasmussen

Lim

et al. 2020

The American Journal of Clinical Nutrition

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Background Phenylalanine is an indispensable amino acid and, via tyrosine, is the precursor for the neurotransmitters dopamine, norepinephrine, and epinephrine. Currently, dietary requirements for phenylalanine during pregnancy are unknown. Objectives This study's aim was to determine phenylalanine requirements (in the presence of excess tyrosine) during early and late gestation using direct amino acid oxidation (DAAO; with l-[1-13C]phenylalanine) and indicator amino acid oxidation (IAAO; with l-[1-13C]leucine). Methods Twenty-three healthy women (age: 30.4 ± 3.1 y, mean ± SD) were studied at a range of phenylalanine intakes (5.5–30.5 mg · kg−1 · d−1 in early and late pregnancy using DAAO, and 2.5–30.5 mg · kg−1 · d−1 in late pregnancy using IAAO) for a total of 76 study days. Test intakes were provided as 8 isocaloric and isonitrogenous meals with 1.5 g · kg−1 · d−1 protein and energy at 1.7 times the measured resting energy expenditure. Breath samples were analyzed on an isotope ratio mass spectrometer for 13C enrichment. Phenylalanine requirement was determined using a 2-phase linear regression crossover model to identify a breakpoint in 13CO2 production (representing the mean requirement) in response to phenylalanine intakes. Results Phenylalanine requirement during early pregnancy was determined to be 15 mg · kg−1 · d−1 (95% CI: 10.4, 19.9 mg · kg−1 · d−1); during late pregnancy, it was determined to be 21 mg · kg−1 · d−1 by DAAO (95% CI: 17.4, 24.7 mg · kg−1 · d−1) and IAAO (95% CI: 10.5, 32.2 mg · kg−1 · d−1). Conclusions Our results suggest a higher requirement (40%) for phenylalanine during late pregnancy than during early pregnancy. Moreover, the early pregnancy requirements are higher than the previous adult male requirement (9.1 mg · kg−1 · d−1; 95% CI: 4.6, 13.6 mg · kg−1 · d−1), although the 95% CIs overlap. Both DAAO and IAAO methods provided similar breakpoints in late pregnancy, showing that the DAAO method was appropriate even though low phenylalanine intakes could not be tested. These results have potential implications for gestation stage–specific dietary phenylalanine recommendations in future. This trial was registered at clinicaltrials.gov as NCT02669381.

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Section: Discussionsupporting

confidence: 62%

Dietary phenylalanine requirements during early and late gestation in healthy pregnant women

Ennis

Rasmussen

Lim

et al. 2020

The American Journal of Clinical Nutrition

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“…Studies carried out in pigs have shown that during late pregnancy when fetal growth is fastest the requirement for amino acids is highest ( 14 – 16 ) . Therefore, it was surprising that the magnitude of change in leucine kinetics from the first to the third trimester was not as great as that observed from the first to the second trimester.…”

Section: Discussionmentioning

confidence: 99%

“…This raises the possibility that in the case of adolescent girls poorer fetal growth relative to that observed in pregnant adult women is the consequence of an inability to make the necessary adaptations in protein turnover and amino acid oxidation. This is the case especially during late gestation when fetal growth is fastest and the requirement for amino acids is highest ( 14 – 16 ) . The objective of the present study was to determine whether there were differences between adolescent girls and adult women during pregnancy with regard to amino acid supply and rates of amino acid oxidation as well as protein synthesis and degradation.…”

mentioning

confidence: 99%

Adaptation of in vivo amino acid kinetics facilitates increased amino acid availability for fetal growth in adolescent and adult pregnancies alike

et al. 2014

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During pregnancy, adult women with a normal BMI synthesise extra amino acids after an overnight fast by increasing body protein breakdown and decreasing amino acid oxidation. It is not known whether adolescent girls can make these adaptations during pregnancy. The present study aimed to measure and compare the protein, glutamine and alanine kinetics of adult women and adolescent girls at early-, mid-and late-pregnancy. Kinetics were measured in the overnight fasted state using intravenous infusions of N 2 -urea in ten adults and eleven adolescents aged 16-17 years in the first and third trimesters (phase 2 study). In phase 1 study, there were no significant differences between the groups with regard to any of the kinetic parameters measured. In both groups, leucine flux increased (P,0·05), the percentage of leucine flux oxidised decreased (P,0·05) and non-oxidative leucine disposal to protein synthesis increased (P,0·05) from the first to the second trimester. In phase2 study, leucine flux was significantly slower (P,0·05) in the adult group than in the adolescent group during both trimesters, and whole-body leucine flux and non-oxidative leucine disposal increased significantly in the adolescent group (P,0·05, respectively) and were higher in the adult group from the first to the third trimester. These results suggest that similar to their adult counterparts after an overnight fast, adolescent girls with a normal BMI provide extra amino acids required for net protein deposition during pregnancy by increasing protein breakdown and decreasing amino acid oxidation.

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“…Each horse received a priming dose (10.2 µmol/kg) and a 4-hour constant rate infusion (7.2 µmol/kg/h) of 1-13 C phenylalanine f for measurement of whole-body phenylalanine kinetics. 26 A phenylalanine isotope infusion for measurement of whole-body protein metabolism has been used for humans 14,27,28 and swine 29,30 ; the method was recently validated for horses. 15 The ratio (approx 1.5:1) of the priming dose to the constant rate infusion dose was determined on the basis of results of another study of horses.…”

Section: Methodsmentioning

confidence: 99%

Whole-body phenylalanine kinetics and skeletal muscle protein signaling in horses with pituitary pars intermedia dysfunction

Mastro¹,

Adams²,

Urschel³

2014

ajvr

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Isoleucine requirement of pregnant sows1

Cited by 12 publications

References 14 publications

Dietary phenylalanine requirements during early and late gestation in healthy pregnant women

Dietary phenylalanine requirements during early and late gestation in healthy pregnant women

Adaptation of in vivo amino acid kinetics facilitates increased amino acid availability for fetal growth in adolescent and adult pregnancies alike

Whole-body phenylalanine kinetics and skeletal muscle protein signaling in horses with pituitary pars intermedia dysfunction

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