Women's Menstrual Cycles Could Offer Clues to Lung Disease Therapies
The changes that a woman's body undergoes during her monthly menstrual cycle could offer clues into potential therapies for people who have advanced lung diseases and need ways to improve how they absorb oxygen.
During a portion of the menstrual cycle, a woman's ovaries and the lining of her uterus become enriched with blood vessels in preparation for possible reproduction. But if there is no fertilized egg, the uterine lining is discarded as the menstrual flow. The uterus returns to its normal state until the process starts again the following month.
Scientists have studied different factors that control blood vessel formation and regression in the uterus. Among these are: hormones such as estrogen; proteins that control blood vessel growth such as vascular endothelial growth factor; and adult stem cells, derived from bone marrow that circulate in the blood, called endothelial progenitor cells (or EPC).
The question was do these factors also encourage blood vessel formation in the lungs?
Researchers in the Institute's Department of Pathobiology found that microscopic blood vessels in the lung increase and decrease in the same rhythm as a woman's uterine lining changes. These blood vessels are critical to pulmonary gas transfer ? the exchange of oxygen for carbon dioxide that occurs in the lungs with each breath we take. The study monitored and tested 10 healthy, non-smoking women in their early 30s during their menstrual cycles (four healthy, non-smoking males were used as a control group). It also looked at blood vessels in mice receiving estrogen or placebo. Among the findings:
? Mice that received estrogen had a greater number of microvessels and more and smaller alveoli, the small air sacs found in lungs that are the work horses during gas transfer. Together the smaller alveoli and the rich networks of new micro blood vessels increase the surface area available for transferring gases.
? Circulating EPCs clearly are related to changes in gas exchange in lung tissues.
? The lung-diffusing capacity in women increased by 10% when the blood vessel formation was at its peak during the menstrual cycle, demonstrating improved gas transfer.
?It's clear that the same factors that cause blood vessel development in the uterus and ovaries during a menstrual cycle are critical factors to how well lungs transfer gases,? said Serpil Erzurum, M.D., Chair, Pathobiology, in whose laboratory the research was conducted. ?This understanding of what governs gas transfer in the lung could lead to therapies that encourage blood vessel formation in the lungs of patients with advanced lung diseases. Any way we can improve or augment oxygen intake by these patients will be a step forward in their care.?
The research also might lead to new understanding of airflow obstructions, suhc as asthma, that occur in some women around the time of their menstrual cycle.
?Understanding what underlies the cause of these diseases can help us to treat the symptoms better,? said lead researcher Samar Farha, M.D., Cleveland Clinic Department of Pulmonary, Allergy & Critical Care Medicine. Dr. Farha is recruiting participants for an ongoing study to understand pulmonary arterial hypertension, or high blood pressure within the arteries in the lungs.
?Women are particularly predisposed to diseases of the arteries and veins within the lungs. These diseases might involve the same causes that we revealed in our research,? Dr. Farha said. ?This gives us hope that we can identify new therapies for women with these types of diseases.?
Other collaborators on the project were Kewal Asosingh, Ph.D., Daniel Laskowski, Lauren Licina, and Raed Dweik, M.D., all of Pathobiology; Herbert Wiedemann, M.D., Chair, Cleveland Clinic Institute of Pulmonary Medicine; and Haruki Sekigushi and Douglas Losordo, M.D., both of the Northwestern Memorial Hospital Division of Cardiology in Chicago.The report appeared in Journal of Applied Physiology (http://jap.physiology.org/; 2007 103: 1789-1795). It was supported by the National Institutes of Health's National Heart, Lung and Blood Institute.
The changes that a woman's body undergoes during her monthly menstrual cycle could offer clues into potential therapies for people who have advanced lung diseases and need ways to improve how they absorb oxygen.
During a portion of the menstrual cycle, a woman's ovaries and the lining of her uterus become enriched with blood vessels in preparation for possible reproduction. But if there is no fertilized egg, the uterine lining is discarded as the menstrual flow. The uterus returns to its normal state until the process starts again the following month.
Scientists have studied different factors that control blood vessel formation and regression in the uterus. Among these are: hormones such as estrogen; proteins that control blood vessel growth such as vascular endothelial growth factor; and adult stem cells, derived from bone marrow that circulate in the blood, called endothelial progenitor cells (or EPC).
The question was do these factors also encourage blood vessel formation in the lungs?
Researchers in the Institute's Department of Pathobiology found that microscopic blood vessels in the lung increase and decrease in the same rhythm as a woman's uterine lining changes. These blood vessels are critical to pulmonary gas transfer ? the exchange of oxygen for carbon dioxide that occurs in the lungs with each breath we take. The study monitored and tested 10 healthy, non-smoking women in their early 30s during their menstrual cycles (four healthy, non-smoking males were used as a control group). It also looked at blood vessels in mice receiving estrogen or placebo. Among the findings:
? Mice that received estrogen had a greater number of microvessels and more and smaller alveoli, the small air sacs found in lungs that are the work horses during gas transfer. Together the smaller alveoli and the rich networks of new micro blood vessels increase the surface area available for transferring gases.
? Circulating EPCs clearly are related to changes in gas exchange in lung tissues.
? The lung-diffusing capacity in women increased by 10% when the blood vessel formation was at its peak during the menstrual cycle, demonstrating improved gas transfer.
?It's clear that the same factors that cause blood vessel development in the uterus and ovaries during a menstrual cycle are critical factors to how well lungs transfer gases,? said Serpil Erzurum, M.D., Chair, Pathobiology, in whose laboratory the research was conducted. ?This understanding of what governs gas transfer in the lung could lead to therapies that encourage blood vessel formation in the lungs of patients with advanced lung diseases. Any way we can improve or augment oxygen intake by these patients will be a step forward in their care.?
The research also might lead to new understanding of airflow obstructions, suhc as asthma, that occur in some women around the time of their menstrual cycle.
?Understanding what underlies the cause of these diseases can help us to treat the symptoms better,? said lead researcher Samar Farha, M.D., Cleveland Clinic Department of Pulmonary, Allergy & Critical Care Medicine. Dr. Farha is recruiting participants for an ongoing study to understand pulmonary arterial hypertension, or high blood pressure within the arteries in the lungs.
?Women are particularly predisposed to diseases of the arteries and veins within the lungs. These diseases might involve the same causes that we revealed in our research,? Dr. Farha said. ?This gives us hope that we can identify new therapies for women with these types of diseases.?
Other collaborators on the project were Kewal Asosingh, Ph.D., Daniel Laskowski, Lauren Licina, and Raed Dweik, M.D., all of Pathobiology; Herbert Wiedemann, M.D., Chair, Cleveland Clinic Institute of Pulmonary Medicine; and Haruki Sekigushi and Douglas Losordo, M.D., both of the Northwestern Memorial Hospital Division of Cardiology in Chicago.The report appeared in Journal of Applied Physiology (http://jap.physiology.org/; 2007 103: 1789-1795). It was supported by the National Institutes of Health's National Heart, Lung and Blood Institute.