The Journal of Asthma Research.
Vol. 13. No. 2 , December. 1975
Editorial
J Asthma Downloaded from informahealthcare.com by UB Kiel on 12/25/14 For personal use only.
Will the Lung Have An Endocrine Function? The adult human lung is a remarkable system of about 300 million air sacs, each one of which is equipped with innumerable capillaries. The walls of these capillaries are about one millionth of a centimeter away from the alveolar cells, that act as a transport membrane for the exchange of gases. Of course, other substances (e.g. corticosteroids) may pass through the alveolar surfaces into the capillaries. Even particulate dusts, if small enough, can migrate through the lung cell membrane. According to Science News (Sept. 6, 1975), recent discoveries may lead the way to the belief that the lung may have an endocrine function, as well as its 80 square meter membrane function. Science News summarizes a session of the American Chemical Society, where the metabolism of two hormones? bradykinin and angiotensin, were discussed. Bakhle reviewed the fact that bradykinin lowers the blood pressure. Angiotensin I, when converted to angiotensin 11, is a most potent substance that raises the blood pressure. When bradykinin passes through the pulmonary vascular bed (not only the capillaries) it is inactivated. On the other hand, angiotensin I is converted to angiotensin 11. Study of this mechanism indicated that a single enzyme was responsible for both conversions. J.W. and U.S. Ryan of the Papanicolou Cancer Research Institute in Miami reported finding the enzyme in the endothelial cells of a pulmonary artery. They were able to confirm their findings by electron microscopy. Although the endothelial cells do not manufacture the hormones, the enzyme system is an endocrine control mechanism which, if found in the capillary endothelial cells, would give the lungs a newly realized and important endocrinological function. This might be damaged when the pulmonary vascular bed is modified by allergic processes. H.A.A.
47
Vol. 13. No. 2 , December. 1975
Editorial
J Asthma Downloaded from informahealthcare.com by UB Kiel on 12/25/14 For personal use only.
Will the Lung Have An Endocrine Function? The adult human lung is a remarkable system of about 300 million air sacs, each one of which is equipped with innumerable capillaries. The walls of these capillaries are about one millionth of a centimeter away from the alveolar cells, that act as a transport membrane for the exchange of gases. Of course, other substances (e.g. corticosteroids) may pass through the alveolar surfaces into the capillaries. Even particulate dusts, if small enough, can migrate through the lung cell membrane. According to Science News (Sept. 6, 1975), recent discoveries may lead the way to the belief that the lung may have an endocrine function, as well as its 80 square meter membrane function. Science News summarizes a session of the American Chemical Society, where the metabolism of two hormones? bradykinin and angiotensin, were discussed. Bakhle reviewed the fact that bradykinin lowers the blood pressure. Angiotensin I, when converted to angiotensin 11, is a most potent substance that raises the blood pressure. When bradykinin passes through the pulmonary vascular bed (not only the capillaries) it is inactivated. On the other hand, angiotensin I is converted to angiotensin 11. Study of this mechanism indicated that a single enzyme was responsible for both conversions. J.W. and U.S. Ryan of the Papanicolou Cancer Research Institute in Miami reported finding the enzyme in the endothelial cells of a pulmonary artery. They were able to confirm their findings by electron microscopy. Although the endothelial cells do not manufacture the hormones, the enzyme system is an endocrine control mechanism which, if found in the capillary endothelial cells, would give the lungs a newly realized and important endocrinological function. This might be damaged when the pulmonary vascular bed is modified by allergic processes. H.A.A.
47
