Related Experiment Video
Updated: May 19, 2026

Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Developmental programming in response to intrauterine growth restriction impairs myoblast function and skeletal
D T Yates1, A R Macko, M Nearing
1Department of Animal Sciences, University of Arizona, Tucson, AZ 85721-0038, USA.
Insights
Fetal growth restriction alters skeletal muscle development, impacting postnatal metabolism. Changes in adrenergic receptors in intrauterine growth restriction (IUGR) fetuses persist, affecting nutrient utilization and potentially leading to metabolic disorders.
Area of Science:
- Developmental biology
- Metabolic homeostasis
- Endocrinology
Background:
- Placental insufficiency causes fetal adaptations impacting skeletal muscle, reducing glucose oxidation, impairing insulin action, and lowering oxidative fibers.
- Intrauterine growth restriction (IUGR) leads to fewer myonuclei in skeletal muscle fibers due to compromised myoblasts.
- Fetal hypoxemia from placental insufficiency elevates catecholamines, hindering fetal muscle growth.
Purpose of the Study:
- To investigate adaptations in adrenergic receptor expression in skeletal muscle and myoblasts of IUGR sheep fetuses.
- To understand how altered adrenergic receptor profiles contribute to metabolic dysfunction in IUGR offspring.
Main Methods:
- Analysis of adrenergic receptor expression profiles in skeletal muscle and myoblasts from IUGR sheep fetuses.
- Comparison of receptor expression between IUGR and control fetuses/lambs.
Main Results:
- IUGR fetuses exhibit altered β-adrenergic receptor expression: decreased Adrβ2 and increased Adrβ1 in myoblasts.
- This altered receptor profile persists postnatally in IUGR lambs, reducing fatty acid mobilization.
- The changes suppress insulin signaling, myoblast incorporation, and glucose oxidation in skeletal muscle.
Conclusions:
- Developmental programming of skeletal muscle adrenergic receptors in IUGR influences postnatal metabolic homeostasis.
- Altered β-adrenergic signaling contributes to differential nutrient utilization and metabolic differences in IUGR offspring.
- These findings highlight a mechanism linking fetal programming to long-term metabolic health.
Abstract:
Fetal adaptations to placental insufficiency alter postnatal metabolic homeostasis in skeletal muscle by reducing glucose oxidation rates, impairing insulin action, and lowering the proportion of oxidative fibers. In animal models of intrauterine growth restriction (IUGR), skeletal muscle fibers have less myonuclei at birth. This means that myoblasts, the sole source for myonuclei accumulation in fibers, are compromised. Fetal hypoglycemia and hypoxemia are complications that result from placental insufficiency. Hypoxemia elevates circulating catecholamines, and chronic hypercatecholaminemia has been shown to reduce fetal muscle development and growth. We have found evidence for adaptations in adrenergic receptor expression profiles in myoblasts and skeletal muscle of IUGR sheep fetuses with placental insufficiency. The relationship of β-adrenergic receptors shifts in IUGR fetuses because Adrβ2 expression levels decline and Adrβ1 expression levels are unaffected in myofibers and increased in myoblasts. This adaptive response would suppress insulin signaling, myoblast incorporation, fiber hypertrophy, and glucose oxidation. Furthermore, this β-adrenergic receptor expression profile persists for at least the first month in IUGR lambs and lowers their fatty acid mobilization. Developmental programming of skeletal muscle adrenergic receptors partially explains metabolic and endocrine differences in IUGR offspring, and the impact on metabolism may result in differential nutrient utilization.
More Related Videos
Related Concept Videos
Formation of Muscle Fibers from Myoblasts
Muscle progenitor cells (MPCs) are formed from the myotomes. MPCs express genes that encode the transcription factors Pax3 and Pax7. Along with Pax 3/7, other transcription factors...
Inborn Errors of Metabolism
Overview of Protein Metabolism
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Cells Coordinate Growth and Proliferation
Teratogenicity
Genomic Imprinting and Inheritance
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...

