Hypoxia enhances agonist-induced pulmonary arterial contraction by increasing calcium sequestration

An experiment was performed to determine the effects of hypoxia on the rabbit's pulmonary artery through the administration of norepinephrine (NE). The additional purpose of the study was to assess the function of extracellular calcium during NE-induced contraction. Phasic and tonic contractions were observed in the intrapulmonary arterial rings. In conclusion, hypoxia increased the calcium pump activity of the pulmonary arterial rings and the concentration of calcium in the sarcoplasmic reticulum.