-transparent.png){kind=logo}
We investigated pressor responses to intravenous bolus infusion of norepinephrine in seven healthy volunteers. Norepinephrine (1, 2, and 4 micrograms/kg) elevated blood pressure in a concentration-dependent manner and decreased heart rate. The pressor response to norepinephrine was biphasic (early and late). Intravenous administration of phentolamine (10 mg) completely abolished the pressor response to norepinephrine, and prazosin (5 mg, given orally) inhibited the early and late responses to a same extent. Continuous intravenous infusion of nicardipine (2 micrograms/kg/min) inhibited the late pressor response but not the early one. These data suggest that bolus infusion of norepinephrine evoked the biphasic pressor response and that the late response depends on vasoconstriction by calcium influx through nicardipine-sensitive calcium channels.
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
November 1962,
The American journal of physiology,
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
January 1991,
Life sciences,
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
January 1964,
Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.),
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
January 1983,
Hypertension (Dallas, Tex. : 1979),
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
February 1992,
Hypertension (Dallas, Tex. : 1979),
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
March 1965,
The Journal of pharmacology and experimental therapeutics,
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
January 1988,
Life sciences,
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
January 1998,
Journal of cardiovascular pharmacology,
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
August 1973,
Experientia,
K Sato, and
M Sawada, and
M Kojima, and
Y Dohi
January 2012,
Clinical physiology and functional imaging,
