 The arterial blood pressure is thought to affect the ratio between filtration and reabsorption of fluids in the circulating blood volume and thereby the plasma volume. During induction of anesthesia blood pressure, hemoglobin level and hematocrits decreases and the plasma volume increases. The aim of the study is to evaluate weather a maintained blood pressure with norepinephrine during anesthesia induction reduces the increase in 125 iodine-labeled human serum albumine 125I-HSA measured plasma volume. 