ARS Project / Heath Family Grant
Ascorbate (vitamin C) and hypoxic pulmonary hypertension
Dr Thomas Smith
Low oxygen levels cause an increase in lung blood pressure which can be pathological - excessive elevation is called pulmonary hypertension, and is a serious condition that can lead to heart failure and death. My research has discovered that iron injections can reverse pulmonary hypertension caused by low oxygen levels. A link between iron and the lungs had never been considered before, but has important implications for treating some patients with lung disease in intensive care or undergoing general anaesthesia. Iron levels affect a particular protein called hypoxia-inducible factor (HIF) which controls lung responses to low oxygen to some extent. In cell-based experiments, HIF activity is influenced by the levels of available vitamin C (ascorbate) as well as the levels of iron. Vitamin C may therefore affect the lungs in the same way that iron does, and would be safer for treating patients. This study aims to determine whether vitamin C inhibits pulmonary hypertension caused by low oxygen. Twelve volunteers will spend eight hours in our laboratory's low-oxygen chamber on two separate days (in random order) - once following a large dose of vitamin C and once following a placebo injection. Lung blood pressure will be measured using echocardiography (heart ultrasound).