Plasma norepinephrine changes after arousal and exercise were enhanced in conscious pigs with perinephritic hypertension.

This study found that pigs in the early stages of perinephritic hypertension had enhanced plasma norepinephrine (NE) and heart rate (HR) responses to behaviorally arousing stimuli (lifting in a canvas sling) and exercise. In the hypertensive animals, the increase in plasma NE in response to behavioral arousal caused by lifting was double that of the intact group, and the HR response was 50% greater. The increase in plasma NE in response to exercise was six times greater in hypertensive pigs. By contrast, mean arterial pressure changes were not enhanced in the hypertensive group. Exaggerated catecholamine responses in plasma to lifting and exercise stimulation were present when hemodynamic responses were not exaggerated.