Vasoactive compound effects on autoregulating versus nonautoregulating intestinal and renal circulations in young swine.

Vascular resistance changes to single intra-arterial injections of norepinephrine, histamine and adenosine were examined in 12 kidney and 10 jejunum preparations perfused in situ in fasting swine anesthetized with pentobarbital. Threshold doses were higher and other response magnitudes were smaller in the nonautoregulating renal circulation of 1-week-olds and jejunal circulation of 2-week-olds than in autoregulating circulations of 1-month-olds. These results suggest a correlation between maturation of autoregulatory capability and of vasodilator histamine and adenosine receptors.