Journal of investigative medicine : the official publication of the American Federation for Clinical Research
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Comparative Study
Hemodynamic response to vasopressin in dehydrated human subjects.
Despite the known potent vasoconstrictor effects of vasopressin, the role of this hormone in the maintenance of blood pressure is incompletely understood. In studies performed in animals with increased plasma vasopressin concentrations, several complex cardiovascular effects have been noted, including decreases in heart rate and cardiac output, which may account for a lack of effect on arterial pressure despite the vasopressin-induced increase in total peripheral resistance. Only a few studies have been done to assess the cardiovascular effects of vasopressin in human subjects, and most of these have been limited to measurement of heart rate and arterial pressure only. The present study was designed to identify more fully the cardiovascular effects of vasopressin when plasma vasopressin concentrations are increased by osmotic stimulation without the superimposition of major nonosmotic stimuli associated with severe volume depletion. ⋯ It is concluded from these studies that small increases in Pavp associated with moderate dehydration do not play a role in the maintenance of arterial pressure in normal human subjects in either supine or erect posture.