Effects of hypoxia on βAR expression: qPCR expression analysis reveals a significant increase in the number of βARs for both β₁ and β₂ adrenergic receptors in the 15 day embryos, where there is a 10-fold difference in their expression in the hypoxic-treated relative to the normoxic-treated samples. This vast increase in βARs in the hypoxic samples is not seen in the 19 day embryos.

Effects of age on hypoxic βAR expression: When comparing age there is a significant difference in the normalized relative β₁:β₂ adrenergic receptor ratio seen in the hypoxic samples. The relative β₁:β₂ expression increases in 15H but decreases in 19H, compared to the normoxic samples for each age.