Accession Number : AD0699903

Title :   THE EFFECT OF CHANGES IN ARTERIAL pCO2 ON ISOGRAVIMETRIC CAPILLARY PRESSURE AND VASCULAR RESISTANCES.

Descriptive Note : Technical rept.,

Corporate Author : OKLAHOMA UNIV MEDICAL CENTER OKLAHOMA CITY

Personal Author(s) : Dietzel,Werner ; Samuelson,Stephen A. ; Guenter,Clarence A. ; Massion,Walter H. ; Hinshaw,Lerner B.

Report Date : 21 JAN 1970

Pagination or Media Count : 17

Abstract : One study was designed to determine the effect of a changing arterial pCO2 on capillary permeability and pre- and postcapillary resistances. Experiments were carried out on isolated forelimbs of dogs perfused with blood equilibrated with different CO2 pressures in an isolated lung. Gas mixtures containing 0%, 5%, and 10% CO2 resulted in arterial mean pCO2 values of 12, 48 and 78 mm Hg. Isogravimetric capillary pressure (Pci) was measured using a modified Pappenheimer and Soto-Rivera technique. Results show the mean Pci rising from 13 to 14.7 mm Hg (p = 0.04) after pCO2 was increased from 48 to 78 mm Hg. When the pCO2 was lowered to 12 mm Hg, Pci fell to 10.1 mm Hg (p = 0.016). Precapillary resistance fell with an increased pCO2 and rose with a decreased pCO2. Effects of pCO2 were believed to alter the permeability of the capillaries due to a direct action on the capillary membrane. The observed changes in capillary permeability are interpreted as a protective mechanism opposed to effects of alterations of capillary hydrostatic pressure resulting from changes in blood pCO2. (Author)

Descriptors :   (*BLOOD CIRCULATION, CAPILLARIES), (*CAPILLARIES, PERMEABILITY), BLOOD VOLUME, PH FACTOR, CARBON DIOXIDE, RESISTANCE(BIOLOGY), MEMBRANES(BIOLOGY), DOGS, BLOOD PRESSURE

Subject Categories : Anatomy and Physiology
      Radiobiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE