Effect of hypervolemia on the adrenergic reactivity of the arterial system

: In anaesthetised rats, dependence of haemodynamics upon increase in the blood volume due to infusion of polyglucin in amounts 1.2 and 2.4 ml (8% and 16% of the blood volume in rats, respectively) < was studied. In the former case the initial blood pressure increased by 30%, in the latter case--by 42%; cardiac output--by 16% and 40%. The metasone pressor effects, at the were reliably decreased by 27% and 65%, and those of general peripheral resistance--by 40% and 80, respectively. The cardiac output changes did not differ significantly. The data obtained suggest an effect of the blood volume increase upon a drop of the arterial system's adrenoreactivity as a result of increase in initial blood pressure.