Whole body methionine kinetics, transmethylation, transulfuration and remethylation during pregnancy.
OBJECTIVE
There is evidence from a study of pregnant American women that methionine transmethylation (TM) and remethylation (RM) rates increases and transulfuration (TS) decreases as pregnancy progresses from trimester 1 to 3. To determine whether pregnant Indian women can make this adaptation successfully, methionine kinetics, TS, TM, and RM were measured in Indian women in early and late pregnancy.


METHODS
Measurements were made in the postabsorptive and fed states in the 1st and 3rd trimesters of pregnancy by infusing 1-(13)C,(2)H3-methionine in 24 women, 12 with low (≤150 pmol L(-1)) and 12 with normal (≥200 pmol L(-1)) vitamin B12 status at recruitment.


RESULTS
From trimester 1 to 3, except RM which decreased significantly, there was no change in any weight-specific methionine kinetic parameter. When expressed per whole body, methionine flux from protein breakdown increased significantly from trimester 1 to 3 in the fed and postabsorptive states. Flux to protein synthesis also increased significantly in the fed state. Rates of TM, TS and RM did not change, regardless of vitamin B12 status at recruitment. Protein and methionine intakes correlated with TM and RM rates and the change in RM from trimester 1 to 3 correlated with the change in dietary protein intake.


CONCLUSIONS
These results suggest that methionine flux and its utilization for protein synthesis increases in Indian women as pregnancy progresses from trimester 1 to 3. TM and RM rates do not increase however, possibly because of inadequate protein intake and not because of vitamin B12 deficiency at trimester 1.
Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, Karnataka 560034, India. Electronic address: a.kurpad@sjri.res.in.
Anura V
AV
Kurpad
Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, Karnataka 560034, India. Electronic address: paulineanand@gmail.com.
Pauline
P
Anand
Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, Karnataka 560034, India. Electronic address: pratibha@sjri.res.in.
Pratibha
P
Dwarkanath
USDA/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: jeanweih@bcm.edu.
Jean W
JW
Hsu
Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, Karnataka 560034, India. Electronic address: tinku.sarah@sjri.res.in.
Tinku
T
Thomas
Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, Karnataka 560034, India. Electronic address: sarita@sjri.res.in.
Sarita
S
Devi
Department of Obstetrics and Gynecology, St. John's Medical College Hospital, Bangalore 560034, India. Electronic address: rejiann@dataone.in.
Annamma
A
Thomas
Department of Obstetrics and Gynecology, St. John's Medical College Hospital, Bangalore 560034, India. Electronic address: ritamhaskar@yahoo.com.
Rita
R
Mhaskar
USDA/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: fjahoor@bcm.tmc.edu.
Farook
F
Jahoor
D000328:Adult; D000886:Anthropometry; D002247:Carbon Isotopes / Q000378:metabolism; D015331:Cohort Studies; D004044:Dietary Proteins / Q000378:metabolism; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007194:India; D008715:Methionine / Q000097:blood* / Q000493:pharmacokinetics*; D008745:Methylation; D011247:Pregnancy / Q000378:metabolism*; D011261:Pregnancy Trimester, First / Q000378:metabolism; D011263:Pregnancy Trimester, Third / Q000378:metabolism; D014805:Vitamin B 12 / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000188:drug therapy; D055815:Young Adult
D002247:Carbon Isotopes; D004044:Dietary Proteins; D008715:Methionine; D014805:Vitamin B 12
Methionine kinetics; PB; PS; Pregnancy; Q(C); Q(M); RM; Remethylation; TM; TS; Transmethylation; Vitamin B(12); carboxy fluxes; methionine methyl; protein breakdown; protein synthesis; remethylation; transmethylation; transsulfuration