Abstract
Summary
The effects of intravascular injection of glucagon (50 μg/kg) on systemic and pulmonary circulations were studied in urethane- and pentobarbital-anesthetized intact dogs. Maximal effects of glucagon were noted at 10 to 15 min after injection in both groups of dogs. Glucagon produced little change or a decrease in cardiac output and a decrease in stroke volume in urethane-anesthetized dogs, whereas it produced a consistent increase in cardiac output in pentobarbital-anesthetized dogs and slight decrease in stroke volume. Heart rate increased and femoral artery pressure decreased significantly in both anesthetic groups. Systemic resistance decreased in pentobarbital-anesthetized dogs and tended to decrease also in urethane-anesthetized dogs. These findings suggest a vasodilator effect of gulcagon. An initial transient rise in pulmonary artery pressure occurred in both groups due to glucagon. This pressure rise was blocked by pretreatment with phenoxybenzamine. Thus, it was at least alpha-adrenergically mediated. Respiratory rate was increased in both groups following glucagon administration.
These studies show that some hemodynamic phenomena are influenced by certain general anesthetics used for animal preparation and that the hemodynamic effects of glucagon should be interpreted with this in mind.
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