Clinical Senior Lecturer
University of Manchester
Dr Adam Greenstein is a consultant physician with responsibility for general medicine,geriatrics and hypertension. Dr Greenstein leads a laboratory research programme investigating why people develop hypertension when they put on weight. Adam's work builds on discoveries made in 2009 demonstrating that fat surrounding blood vessels secretes hormones which lower blood pressure. However, in obese patients, the secretory profile of the fat changes and loss of these hormones leads to abnormal vascular function and hypertension. Dr Adam Greenstein trained in medicine at the University of Manchester, during which he also completed an undergraduate degree in Pharmacology. After completion of junior doctor posts in Manchester, he trained in general and geriatric medicine at Leeds General Infirmary. His PhD, undertaken at the university of Manchester investigated the interplay between adipose tissue and small resistance arteries in obesity and hypertension. Dr Greenstein has published his work in journals such as Circulation, Hypertension and the journal of Hypertension in addition to presenting workshops and new data on the microcirculation at major international conferences. His work is funded in its entirety by the British Heart Foundation. His focus of the lab is on the mechanisms by which adipose tissue (fat) influences blood vessel function, how this adipose-vascular coupling is dysregulated in obesity and subsequently why hypertension develops following weight gain.
We are investigating the vasodilating action of the adipose tissue which surrounds small arteries (PeriVascular Adipose Tissue, or PVAT). In 2009, I published the first human small artery study of PVAT and demonstrated that the vasoactive effects are due to adiponectin release from adipocytes. I also showed that in obese patients the function of PVAT was completely lost because of adipose tissue inflammation. This observation provides a possible explanation for the development of hypertension in obesity. In 2013, we published a follow-up study in the Journal of the American College of Cardiology showing that the function of PVAT was rescued after obese patients underwent bariatric (weight reduction) surgery. A new project with Professor Mark Nelson (see collaborators) is elucidating the cellular mechanisms by which PVAT influences the adjacent small artery. From a clinical perspective, we are examining novel therapeutic strategies to restore PVAT function in obesity and how weight loss changes PVAT function in patients. In a major new development, we were awarded an equipment grant from the British Heart Foundation in order to purchase a high speed spinning disc confocal microscope (Andor Revolution XD). This exciting state of the art technology now enables us to very accurately quantify changes to the intracellular signalling molecule Calcium within vascular smooth muscle, the endothelium and adipose tissue.