Urinary catecholamines in iron-deficient rats at rest and following surgical stress

The purpose of this study was to determine catecholamine concentrations both at rest and in response to a surgical stress in iron-deficient and control rats. Twenty-one-day-old rats were randomized to one of two groups which received a diet containing either 6 or 50 mg iron/kg. Three to five days later, when anemia was first detectable, urinary norepinephrine (NE) concentrations were already significantly elevated in the iron-deficient compared to control rats. In contrast, urinary dopamine (DA) became depressed after 10 days of the iron-deficient regimen. At 38 days of age, both groups were subjected to a surgical stress. NE and DA became elevated over baseline values in both diet groups during the 24-h period following surgery; NE remained significantly higher and DA significantly lower in the iron-deficient than in the control group. We conclude that changes in urine catecholamine concentration occur early in the development of iron deficiency and that they are characteristic of both baseline and stress conditions.