Accession Number : AD0633473

Title :   DISTRIBUTION OF PULMONARY BLOOD FLOW AS AFFECTED BY TRANSVERSE (+GX) ACCELERATION.

Descriptive Note : Final rept.,

Corporate Author : NAVAL AIR DEVELOPMENT CENTER JOHNSVILLE PA AEROSPACE MEDICAL RESEARCH DEPT

Personal Author(s) : Hoppin,Frederic G. , Jr. ; York ,Elihu ; Kuhl ,David E. ; Hyde,Richard W.

Report Date : 31 DEC 1965

Pagination or Media Count : 32

Abstract : The distribution of blood flow in the pulmonary vascular bed under +Gx (forward or transverse acceleration) was studied by the intravenous injection of radioactive 131 Iodinated-macro aggregated albumin (131I-MAA) in three normal subjects while they were under +1Gx, +4Gx and +8Gx on a human centrifuge. The resulting distribution of radioactivity in the lungs, representing the distribution of pulmonary blood flow at the time of injection, was assessed one to three hours later by lateral radioisotope scanning. The distribution of pulmonary blood flow was not markedly different at +1Gx, +4Gx, and +8Gx despite a hydrostatic gradient in pulmonary intravascular pressures estimated to be 88 mm Hg under +8Gx. These findings indicate that under +Gx (forward or transverse acceleration) unlike +Gz (headward or positive acceleration) the distribution of pulmonary blood flow is not markedly distorted, and that the regional flow of blood in the lung may not be significantly changed by high intravascular pressures. (Author)

Descriptors :   (*LUNG, *ACCELERATION TOLERANCE), (*BLOOD CIRCULATION, ACCELERATION TOLERANCE), HYDROSTATIC PRESSURE, RADIOACTIVE ISOTOPES, BLOOD VESSELS, STRESS(PHYSIOLOGY)

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE