Changes in Taurine and Other Free Amino Acid Levels in the Blood of Developing Fetuses

Moriyama, I.; Ueda, Shuji; Akasaki, Masayoshi; Iioka, Hiroshi; Ichijo, Motohiko

doi:10.1111/j.1442-200x.1984.tb02183.x

Cited by 2 publications

(1 citation statement)

References 6 publications

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“…This organ is able to concentrate the taurine of maternal blood [6], through a process of active transport [15]. Taurine con centration in the vein blood of the fetus is on average 2.5 times higher than in the vein blood of the mother [16,17], As taurine seemingly plays an essential role in organic growth and in a certain number of physio logic functions [12,18,19], the quantity of maternal taurine transferred by the placenta could be one of the factors conditioning fetal development. This phenomenon seems to have been confirmed recently in the rat [8], These authors provoked a taurine deficiency in pregnant rats, from days 11-12 of gesta tion by using an antagonist of this amino acid, guanidinoethyl sulfonate (GES).…”

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confidence: 99%

Placental Taurine and Low Birth Weight Infants

et al. 1989

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In order to determine whether the decrease in taurine concentration in the placenta during pregnancy could affect fetal development, as has been observed in animals, we measured the concentration of taurine in placentas obtained after vaginal expulsion. 31 placentas from women with normal pregnancies of over 37 weeks who have given birth to infants of normal weight (3,200 ± 310 g) were included in the study. In addition, 26 placentas of infants considered to be hypotrophic were also included (gestation over 37 weeks, birth weight: 2,260 ± 230 g). The taurine was assayed using gaz-liquid chromatography. The concentration of taurine in the placenta was 2.80 ± 0.56 μmol/g for the placentas of normal birth weight infants and 2.40 ± 0.64 μmol/g for the placentas of hypotropic infants (p < 0.02). There is no significant correlation in normal and hypotrophic newborns between the gestation period, the weight and height at birth, the weight of the placenta, and the taurine concentration in the placenta. The taurine concentration in placentas of hypotrophic born infants is significantly reduced compared to the placentas from normal infants.

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Section: Commentsmentioning

confidence: 99%

Placental Taurine and Low Birth Weight Infants

et al. 1989

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A Study of Taurine Transport and Absorption in Placenta and Neonatal Intestine and Kidney

Moriyama

lioka

Kato

et al. 1987

Pediatrics International

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Serum taurine concentration in the human fetus (umbilical blood) and neonate was measured from the 24th to 40th week of pregnancy. The concentration was considerably higher than in maternal serum with a peak at the 24th week of pregnancy and then a gradual decrease until it approached the adult level on the 9th day after birth.To clarify the underlying mechanism of the human findings, the distribution of 14C‐taurine was investigated after intravenous injection to maternal rats on the 20th day of pregnancy. The taurine administered to the maternal side became concentrated in the placenta and reached the fetus. It was confirmed that taurine accumulated in the human placenta was present in a higher concentration than any other free animo acid.Placental transport of taurine was studied in isolated brush border microvillous plasma membrane vesicles by a rapid filtration technique. The membrane vesicles exhibited uptake of H3‐labeled traurine into an osmotically reactive intravesicular space. Taurine uptake by vesicles was stimulated specifically by an inward sodium gradient, and replacement of NaCl in the transport medium by KCl, LiCl or choline chloride had no effect on the transport activity of the vesicles. Taurine transport was inhibited competivively by the presence of β‐alanine and GABA. The initial rate of transport followed saturation kinetics with respect to taurine concentration: an apparent Km of 0.22 mM and Vmax of 67 pmol/mg protein were calculated in 20 seconds. These results indicate that transport of taurine across the placental brush border membrane is sodium‐dependent and carrier‐mediated.The taurine transport system in human fetal small intestine, especially in the jejunum, is a passive transport system quite unlike that of other amino acids.Reabsorption of taurine through the proximal convoluted tubule is by active transport which depends on sodium. This transport system is developed from the 24th to the 32nd gestational week.

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Changes in Taurine and Other Free Amino Acid Levels in the Blood of Developing Fetuses

Cited by 2 publications

References 6 publications

Placental Taurine and Low Birth Weight Infants

Placental Taurine and Low Birth Weight Infants

A Study of Taurine Transport and Absorption in Placenta and Neonatal Intestine and Kidney

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