What is the main gas transported in the pulmonary artery and how is it transported?

The main gas transported in the pulmonary artery is carbon dioxide (CO2). It is primarily carried in the blood in three forms: dissolved in plasma, as bicarbonate ions (HCO3-) after reacting with water, and bound to hemoglobin as carbamino compounds. The pulmonary artery transports deoxygenated blood from the right ventricle of the heart to the lungs, where CO2 is exchanged for oxygen.