Dr. Rivers' primary interest is vascular communication. He is studying microcirculation physiology to determine how metabolic demands are signaled between the tissue and the vascular network and along the vascular network itself. To conduct his work, Dr. Rivers uses a technique called intravital fluorescence microscopy, which enables him to measure the blood flow within a single artery, vein or capillary. Also, with micropipettes, specific agonists and antagonists can be applied directly to the blood vessel to determine the effect on blood flow in real time.
Dr. Rivers is also working to determine the role for inwardly rectifying potassium channels (Kir) 2.1 and 6.1 in signaling along the vessel wall, as well as the role of gap junctions. One of his initiatives is to develop viral vectors to use as tools to study the promoters that are specific for cell types in the vessel wall. The vectors are used to downregulate proteins such as the potassium channels and gap junctions to determine the effect on vascular function.
Dr. Rivers discovered that using hyaluronidase to break down the extracellular matrix enhances viral expression. In the future, Dr. Rivers may use RNA interference (RNAi) as another method for downregulating the proteins. He is also testing mice with specific gene deletions in his experimental models.
Ultimately, Dr. Rivers hopes that a better basic understanding of the microcirculation will lead to a better comprehension of disease processes, such as the angiogenesis that occurs in cancer and circulatory dysfunction associated with diabetes. This knowledge at the molecular level could enable the development of specific drugs that can target these processes and limit disease progression.
Miriel VA., Chen Y, Rivers RJ. "The involvement of CGRP, adrenomedullin, and sensory nerves in remote vasomotor responses within the hamster cheek pouch microcirculation." Microvasc Res. 2009 Mar;77(2):192-7. doi: 10.1016/j.mvr.2008.10.006. Epub 2008 Nov 19.
Thengchaisri N, Miriel VM, and Rivers RJ. "Multiple receptor subtypes and multiple mechanisms of dilation are involved in the vascular network dilation caused by adenosine." Microvasc Res. 2009 May;77(3):356-63. doi: 10.1016/j.mvr.2009.01.004. Epub 2009 Jan 27.
Frank SM, Savage WJ, Rothschild JA, Rivers RJ, Ness PM, Paul SL, Ulatowski JA. "Variability in blood and blood component utilization as assessed by an anesthesia information management system." Anesthesiology. 2012 Jul;117(1):99-106. doi: 10.1097/ALN.0b013e318255e550.
Frank SM, Savage W, Rothschild JA, Rivers RJ, Ness PM, Paul SL, Ulatowski JA. "Optimizing preoperative blood ordering with data acquired from an anesthesia information management system." Anesthesiology. 2013 Jun;118(6):1286-97. doi: 10.1097/ALN.0b013e3182923da0.
Ibrahim MA, Do DV, Sepah YJ, Shah SM, Van Anden E, Hafiz G, Donahue JK, Rivers RJ, Balkissoon J, Handa JT, Campochiaro PA, Nguyen QD. "Vascular disrupting agent for neovascular age related macular degeneration: a pilot study of the safety and efficacy of intravenous combretastatin a-4 phosphate." BMC Pharmacol Toxicol. 2013 Jan 14;14:7. doi: 10.1186/2050-6511-14-7.