Redistribution of blood volume during the onset of deoxycorticosterone acetate-salt hypertension

The splanchnic veins are known to hold the largest amount of blood within the circulation. Structural and/or neurohormonally mediated changes in the diameter of these vessels can lead to a reduction in splanchnic vascular capacitance and blood volume. This causes an increase in cardiac filling pressure as blood is translocated towards the heart. The resulting redistribution of blood into the arterial circulation could be a factor in the development hypertension. Previous data suggests that a reduction in vascular capacitance may play a pivotal role in the pathogenesis of hypertension in the DOCA-salt model, but no direct measurement of volume shifts have been reported. The purpose of my research is to assess blood volume redistribution during the onset of DOCA-salt hypertension using bioimpedance measurement. Regional bioimpedance allows for the measurement of total fluid content in specific body compartments. For this study I developed a method for repeated measurements of regional bioimpedance in conscious, unrestrained rats over several weeks. Using this technique, I am able to show an increase in impedance in the abdominal region in DOCA-salt treated rats (most likely indicating a decrease in fluid content). I conclude that fluid translocation from the abdominal region due to decreased venous capacitance may participate in the development of DOCA-salt hypertension.