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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Which of the following is inactivated in the lung?
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The correct answer is  Vasoactive substances on their passage through the lungs are completely or paially inactivated. Bradykinin is a potent vasodilator that is not synthesized in the lung, but is largely inactivated in the pulmonary endothelium following degradation by angiotensin conveing enzyme. About 80% of bradykinin is inactivated in the lung. The lung is also the major site of inactivation of serotonin but this is by uptake and storage process not by enzymatic degradation. Angiotensin I is conveed to angiotensin II by angiotensin conveing enzyme (ACE). There is no effect on angiotensin II and vasopressin. Ref: Respiratory physiology, By John B West, 9th Edition, Page 52.