What question did this study set out to answer?

To evaluate the hormonal regulation of system A amino acid transporter activity in term human placenta using isolated single primary villous fragments.

March 1, 2003The Journal of Clinical Endocrinology & MetabolismOpen Access

Leptin Stimulates the Activity of the System A Amino Acid Transporter in Human Placental Villous Fragments

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Authors

NJN. JanssonUniversity of Gothenburg SGSusan GreenwoodManchester Academic Health Science Centre BJBörje JohanssonLund University

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Implication

Experimental study demonstrates that leptin stimulates system A amino acid transport in human placental villous tissue, indicating a direct endocrine mechanism supporting fetal nutrient supply.

Key Points

To evaluate the hormonal regulation of system A amino acid transporter activity in term human placenta using isolated single primary villous fragments.
Maintained isolated primary human placental villous fragments ex vivo, verifying functional and ultrastructural viability for up to 3 hours using electron microscopy and hormone assays.
Measured system A transporter activity via Na(+)-dependent uptake of methylaminoisobutyric acid (MeAIB) following 1-hour incubation with insulin, leptin, epidermal growth factor, cortisol, or growth hormone.
Leptin (500 ng/ml, n = 14) increased Na(+)-dependent MeAIB uptake by 37% (P < 0.05), stimulating system A activity in a concentration-dependent manner (n = 10).
Insulin increased system A activity by 56% at 300 ng/ml (n = 14, P < 0.05) and by 47% at a physiological concentration of 0.6 ng/ml (n = 10, P < 0.05).
Epidermal growth factor (600 ng/ml), cortisol (340 ng/ml), and growth hormone (500 ng/ml) produced no significant changes in system A transporter activity (n = 14).

Cite This Study

Jansson et al. (2003) studied this question.

synapsesocial.com/papers/6a6f993f26a7f98052dc3c0b https://doi.org/10.1210/jc.2002-021332

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Implication

Experimental study demonstrates that leptin stimulates system A amino acid transport in human placental villous tissue, indicating a direct endocrine mechanism supporting fetal nutrient supply.

Leptin Stimulates the Activity of the System A Amino Acid Transporter in Human Placental Villous Fragments

Discussion

Member takes

Implication

Key Points

Cite This Study

Leptin Stimulates the Activity of the System A Amino Acid Transporter in Human Placental Villous Fragments

Discussion

Member takes

Implication

Key Points

Cite This Study

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