Related Experiment Videos
Insulin receptors in the newborn. Increase in receptor affinity and number
Insights
Fetal cells have significantly more insulin receptors than adult cells. This finding highlights insulin's crucial role in fetal growth and development during pregnancy.
Area of Science:
- Endocrinology
- Developmental Biology
- Cell Biology
Background:
- Insulin is recognized as a potential growth factor during fetal development.
- Understanding the specific role of insulin in fetal development requires examining its receptors on fetal cells.
Purpose of the Study:
- To investigate and clarify the function of insulin receptors in the fetus.
- To compare insulin receptor characteristics between newborns and adults.
Main Methods:
- Mononuclear leukocytes were isolated from placental-cord blood of 12 normal newborns.
- Insulin receptor binding assays were performed on leukocytes from newborns and 8 adult controls.
- Quantified specific binding, receptor site number, and receptor affinity (Ke).
Main Results:
- Newborns exhibited significantly higher specific insulin binding on monocytes compared to adults (24.3% vs. 4.7%).
- This increased binding in newborns is attributed to a greater number of receptor sites per cell (44,600 vs. 7100) and higher receptor affinity (Ke = 5.9 x 10(8) M(-1) vs. 2.9 x 10(8) M(-1)).
Conclusions:
- Fetal cells possess markedly higher concentrations of high-affinity insulin receptors.
- These findings support the critical role of insulin in mediating intrauterine growth and fetal development.
Abstract:
Insulin hs been implicated as a growth factor in fetal life. To clarify the role of insulin in the fetus, we studied insulin receptors on mononuclear leukocytes in placental-cord blood from 12 normal newborns. Eight healthy young adults served as controls. Specific binding (mean +/- S.E.M.) in the absence of unlabeled insulin per 10(7) monocytes was, respectively, 24.3+/-3.5 and 4.7+/-0.9 per cent in newborns and adults. This increase in binding is due to a rise in number of receptor sites per cell (newborns, 44,600, and adults, 7100) as well as an increase in receptor affinity (Ke for newborns = 5.9 X 10(8) M(-1), and that for adults = 2.9 X 10(8) M(-1). This finding of markedly high concentrations of high-affinity receptors for insulin on fetal cells supports the importance of insulin in intrauterine growth and development.