Transfer of D- and L-Histidine across the Human Placenta*†

Page, Ernest W.; Glendening, Mary Beth; Margolis, Alan J.; Harper, Harold A.

doi:10.1016/s0002-9378(16)37431-2

Cited by 65 publications

(12 citation statements)

References 10 publications

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“…Our data for L-methionine, L-leucine, and L-ornithine, taken together with considerable other data from a number of laboratories [3,4,8,9,11,17,21,22], is compatible with the hypothesis that, in general, amino acids are transferred from mother to fetus by a process of active transport, i.e., carrier-mediated, saturable, energy-dependent, stereospecific, and operating against a chemical gradient.…”

Section: Discussionsupporting

confidence: 88%

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Transfer of Cyst(e)ine and Methionine across the Human Placenta

et al. 1973

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ExtractAfter intravenous loads in pregnant women, L-methionine, L-leucine, and L-ornithine were transferred from maternal to fetal plasma against a two-to threefold difference in initial concentration. Cyst(e)ine is unique among the free amino acids of plasma in that its basal concentration in maternal plasma was equal to or greater than that in fetal plasma. Furthermore, after intravenous loads with L-cystine or L-cysteine, total cyst(e)ine (cystine and cysteine) was transferred less readily to the fetal plasma. Although the concentrations of cystine in the fetal plasma continued to rise in the face of rapidly falling concentrations of cystine in the maternal plasma, at no time during the experiment did the concentration of cystine in fetal plasma exceed that in the maternal plasma. When D-cystine was administered intravenously to a mother, in amounts equimolar with L-cystine, the transfer of D-cystine was not measurable. SpeculationCyst(e)ine is the end-product of the transsulfuration pathway, which transfers the sulfur from the 4-carbon skeleton of methionine to the 3-carbon skeleton of serine. Methionine-activating enzyme, the first enzyme on this pathway, is inhibited by cyst(e)ine [2,5,20]. It is also allosteric [19], a characteristic often associated with negative feedback inhibition. Cystathionase, which cleaves cystathionine to cysteine and a-ketobutyrate and is the last enzyme on this pathway, is absent from the liver and brain of the human fetus. Therefore, we postulate that the special mechanism for the transfer of cyst(e)ine across the human placenta is an adaptation to control the transfer of sufficient maternal cyst(e)ine for synthesis of protein and glutathionine without undue inhibition of the activation of methionine to iS'-adenosylmethionine, a compound involved in important synthetic reactions.

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Section: Discussionsupporting

confidence: 88%

“…The general observation of the higher concentration of amino acids in fetal plasma had been made in a number of laboratories [8,11,18,21,22]. That cysteine was an exception was previously unappreciated.…”

Section: Resultsmentioning

confidence: 99%

Transfer of Cyst(e)ine and Methionine across the Human Placenta

et al. 1973

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“…These workers also provided evidence of competitive inhibition between glycine and histidine and between methionine and proline. Saturation of the transport mechanism for histidine was shown by Dancis,Olson 584 MARGARET L. REYNOLDS AND MAUREEN YOUNG & Folkhart (1958) and selective transport of the natural L isomer of histidine has been observed in the human subject by Page, Glendenning, Margolis & Harper (1957), and Mischel (1963).…”

Section: Introductionmentioning

confidence: 93%

The transfer of free α‐amino nitrogen across the placental membrane in the guinea‐pig

Reynolds¹,

Young²

1971

The Journal of Physiology

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SUMMARY1. Transfer of endogenous a-amino nitrogen from the maternal to foetal side of the placental membrane was studied in the foetal guinea-pig placenta perfused, in situ via the umbilical vessels, with an artificial fluid. Changes in maternal placental blood flow were followed by measuring the transfer of antipyrine into the perfusate.2. Active transport by the membrane was demonstrated under these conditions by observing the increased ratio of L/D leucine appearing in the perfusate in comparison with the maternal plasma ratio.3. Reduction in maternal placental flow following haemorrhage was associated with a fall in transfer of amino nitrogen to about half of the control values.4. The concentration of ax-amino nitrogen in the perfusate was inversely proportional to the foetal placental flow which had a smaller influence on amino nitrogen transfer per min than did the maternal blood flow.5. Hypoxia and some inhibitors of oxidative metabolism were without influence on the transfer of a-amino nitrogen in this preparation.

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“…The silver grains were abundant in the glycogen area, Golgi apparatus, and myofibrils, but they were especially abundant in the mitochondria. This indicates that thiamine is taken up by these organelles and employed in the cell metabolism.There are many clinical and biochemical studies on the uptake by fetal organs of various substances which were injected into the maternal bloodstream and transported across the placenta.Such are the studies of PAGE et al (1957) on histidine, SLOBODY (1961) on medicines, YAMAGUCHI (1962) on electrolytes and anesthetics, SAKAMOTO and OTA (1966) on oxygen and carbonic acid gas, SUZUKI and HANDO (1966) on medicines, and YAMAGUCHI and KIMURA (1966) on sugars, amino acids, and electrolytes.However, there are few morphological studies on the conditions of the fetal organs after taking up these substances. IDANPAAN-HEIKKILA and SCHOOLAR (1969) injected pregnant mice with 14C-lysergic acid diethylamide, and then studied its uptake by the fetal organs by total body autoradiography.…”

mentioning

confidence: 99%

“…Such are the studies of PAGE et al (1957) on histidine, SLOBODY (1961) on medicines, YAMAGUCHI (1962) on electrolytes and anesthetics, SAKAMOTO and OTA (1966) on oxygen and carbonic acid gas, SUZUKI and HANDO (1966) on medicines, and YAMAGUCHI and KIMURA (1966) on sugars, amino acids, and electrolytes.…”

mentioning

confidence: 99%

The Passage of Thiamine across the Rat Placenta and Its Uptake by the Fetal Organs

Uchida¹,

Daimon²,

Mizuhira³

1977

Arch. Histol. Jap., Arch. Histol. Jpn

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Summary. Having injected 3H-thiamine into the maternal bloodstream of rats in their 15th day of pregnancy, the uptake by the fetal organs (liver and cardiac muscle) of the 3H-thiamine which had been transported across the placenta was studied by electron microscope autoradiography and by measuring the radio-activity of the tissues, using the same methods reported in the first paper of this series. In the fetal liver both developed silver grains and radioactivity were found in greatest amounts in specimens collected 5hrs after injection. Developed silver grains were abundant in the mitochondria, Golgi apparatus, rough-surfaced endoplasmic reticulum, glycogen area, and nucleus, indicating that these cell organelles take up thiamine and utilize it for the cell metabolism. In the fetal cardiac muscle, the developed silver grains and radioactivity were found in greatest amounts 2hrs after injection. The silver grains were abundant in the glycogen area, Golgi apparatus, and myofibrils, but they were especially abundant in the mitochondria. This indicates that thiamine is taken up by these organelles and employed in the cell metabolism.There are many clinical and biochemical studies on the uptake by fetal organs of various substances which were injected into the maternal bloodstream and transported across the placenta.Such are the studies of PAGE et al. (1957) on histidine, SLOBODY (1961) on medicines, YAMAGUCHI (1962) on electrolytes and anesthetics, SAKAMOTO and OTA (1966) on oxygen and carbonic acid gas, SUZUKI and HANDO (1966) on medicines, and YAMAGUCHI and KIMURA (1966) on sugars, amino acids, and electrolytes.However, there are few morphological studies on the conditions of the fetal organs after taking up these substances. IDANPAAN-HEIKKILA and SCHOOLAR (1969) injected pregnant mice with 14C-lysergic acid diethylamide, and then studied its uptake by the fetal organs by total body autoradiography.We injected 3H-thiamine into the maternal bloodstream of pregnant rats and studied its uptake by the fetal liver and cardiac muscle with electron microscope autoradiography, at the same time measuring the radioactivity of the two types of tissue. Materials and MethodsAs described in the first paper of this series, we injected the thiamine derivative of 200g female rats in their 15th day of pregnancy, collected the fetal liver at 30min, 2hrs, and 5hrs after injection, fixed, dehydrated, and embedded the tissues with 23

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Transfer of D- and L-Histidine across the Human Placenta*†

Cited by 65 publications

References 10 publications

Transfer of Cyst(e)ine and Methionine across the Human Placenta

Transfer of Cyst(e)ine and Methionine across the Human Placenta

The transfer of free α‐amino nitrogen across the placental membrane in the guinea‐pig

The Passage of Thiamine across the Rat Placenta and Its Uptake by the Fetal Organs

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