Abstract Th0070: Osmosensitive Transporter Expression in Resistance-Sized Arteries

Due to its importance in maintaining homeostasis of many physiological processes in the body, including the cardiovascular system, it’s crucial that humans consume water, to replace any loss that occurs through urine, sweat, feces, and expelled air. Unfortunately, a significant proportion of the global population either does not have a safe drinking water source or consistent access to water throughout the year and with water scarcity projected to only impact more people in the future, it’s important to understand what is the effect of water deprivation on the human body. Once the body loses a greater amount of water than it’s able to intake it enters the process of dehydration, resulting in a body water deficit, known as hypohydration. Even mild dehydration can affect an individual's mental and physical well-being, with an association between chronic dehydration and adverse cardiovascular outcomes, including hypertension, stroke, and coronary heart disease (CHD). While most research is focused on acute dehydration, chronic low water intake, also termed underhydration, is also associated with adverse health outcomes. However, the effect of acute and chronic reductions in water intake on the function of resistance-sized arteries, that regulate systemic blood pressure, is unclear. In response to long-term hyperosmotic stress, osmolyte accumulation through transporters has an important role in the maintenance of cell volume homeostasis, with specifically three transporters, the taurine transporter (TauT), myoinositol transporter (SMIT-1), and betaine transporter (BGT-1) thought to contribute to this process. In this study, SMIT-1 and BGT-1 expression, but not TauT expression, were elevated in resistance-sized mesenteric and hindlimb mouse arteries by 48 hours of water deprivation and 28 days of reduced water intake. These findings suggest that mice adjust to alterations in water intake, by altering the expression of osmosensitive transporters in resistance-sized arteries, indicating that the transport of myoinositol and betaine may be crucial to maintaining cardiovascular homeostasis during water duress.