[The influence of dopamine on the regional blood volume in liver, abdomen, chest and extremities (author's transl)].

The influence was studied of 3 and 6 gamma/kg/min. dopamine on the blood volume in the liver, abdomen, chest, arms and legs in ten volunteers with healthy livers, and a comparison was made between the effect of dopamine and the blood volume changes caused in these body regions by inflatable whole-leg boots at a pressure of 40 mm Hg. Regional blood volumes and any induced changes were studied by means of 99 m Tc labelled autologous erythrocytes. A gamma camera with a pinhole collimator and a small computer was used, the field of vision of the camera being 148 cm in diameter. Changes in regional activity reflect changes in the regional blood volume. 1. Whole-leg compression at 40 mm Hg led to an increase in the blood volume of the liver, abdomen and chest, but to a reduction in the legs, while no significant change was observed in the arm blood volume. 2. On infusion of 3 gamma/kg/min. dopamine for 15 minutes no significant change occurred in the blood volume of the liver and abdomen. The chest blood volume increased, while the blood volume of the upper and the lower extremities showed a statistically significant decrease. 3. On infusion of 6 gamma/kg/min. dopamine for 10 minutes no significant change occurred in the blood volume of the liver, while the chest blood volume continued to rise and that of the upper and lower limbs continued to fall. 4. Ten minutes after the end of the infusion there was no significant change in liver and abdominal blood volume as compared with the last value measured during infusion of 6 gamma/kg/min. dopamine. By that time the chest blood volume had already fallen and the blood volume of the arms and legs increased. The possible action mechanisms via dopamine-specific and other catecholamine receptors are discussed in this paper.