THE EFFECT OF THE UPRIGHT POSTURE UPON HEPATIC BLOOD FLOW IN NORMOTENSIVE AND HYPERTENSIVE SUBJECTS 1

Abstract

During upright (75[degree]) tilting, hepatic blood flow, as estimated by the BSP [bromosulphophthalein ] extraction method, decreased in 8 normotensive subjects from an avg. of 1713 to 1070 cc./min. and in 12 hypertensive patients from 1357 to 960 cc./min. The avg. arterial pressure did not change, so that calculated hepatic-portal resistance increased from 3.8 to 5.5 units in the normotensive group and from 7.3 to 10.1 units in the hypertensive group. These changes were significant statistically. On returning from the upright to the horizontal position hepatic blood flow rose from 1070 to 1312 cc./min. in the normotensive group and from 960 to 1417 cc./min. in the hypertensive group, while hepatic-portal resistance decreased from 5.5 to 4.9 and from 10.1 to 7.2 units in the 2 groups, respectively. Hepatic blood flow failed to change regularly in six subjects after immersion of a hand in ice water for 1 minute.