Norepinefrin - noradrenalin

Norepinephrine

• In the lung, approximately 25%-50% is extracted and degraded during a single pass through the pulmonary circulation
• The primary site for removal of norepinephrine is pulmonary capillary endothelial cells
• Inactivation of norepinephrine in the lung affects systemic arterial blood concentration of norepinephrine
• Lung can be regarded as a biochemical filtration system in regulating the effects of norepinephrine

• Sympathetic nerves are present in the walls of 30- to 300- am pulmonary arteries and of larger pulmonary veins
• Stimulation of the sympathetic nerves causes
• Pulmonary vasoconstriction
• Increased transcapillary lymph and protein flow in the lung
• Pulmonary vascular resistance and transcapillary fluid exchange
• MIBG is taken up in the lung by the same mechanism as norepinephrine