Effects of dose and administration mode of endothelin 1 on the mean arterial pressure and heart rate in awake rats

The effects of bolus administration and short-term infusion of endothelin 1 in four doses (2×10⁻¹⁶, 2×10⁻¹⁴, 2×10⁻¹², and 2×10⁻¹⁰ mol/kg) on arterial pressure and heart rate were compared in awake rats. Infusion and bolus administration of the two highest doses increased arterial pressure and provoked bradycardia. Infusion of the two lowest doses increased heart rate without concomitant changes in arterial pressure, while bolus injection of endothelin 1 in the same doses decreased both arterial pressure and the heart rate. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 11, pp. 491–494, November, 1997