The Nature of the Carbon Dioxide Titration Curve in the Normal Dog*

Cohen, Jordan J.; Brackett, Newton C.; Schwartz, William B.

doi:10.1172/jci104964

Cited by 101 publications

(27 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1. Over the range studied this relationship appears to be linear, in agreement with the observations of Barcroft, Bock, Hill, Parsons, Parsons and Shoji (1922); Cohen et al (1964) and Brackett et al (1965). For each patient Williams (1959).…”

Section: Resultssupporting

confidence: 89%

See 1 more Smart Citation

THE IN VIVO CARBON DIOXIDE TITRATION CURVE IN MAN DURING REBREATHINC

Despas

Leigh

1970

Aust J Exp Biol Med

View full text Add to dashboard Cite

Summary. The in vivo titration curve of CO, measured in five subjects during rebreathing of 7% COg in O2 for 3 minutes was not significantly different from the corresponding in vitro titration curve measured on arterial blood from each subject. The buffering of COg m vivo when measured by other methods is known to be less than it is in vitro. COj in vivo is thought to equilibrate with a well buffered compartment (intravascular) and a poorly buffered compartment (interstitial fiuid). It has been suggested that HCO3-shift takes place from the intravascular compartment. During rebreathing there may be insufficient time for HCO3-shift to occur. This would explain the identical COg titration curves in vivo and in vitro shown by this study. INTRODUGTION.The GO2 titration curve of whole blood in vivo has been obtained by exposing normal man and dogs to progressively higher levels of inspired GOî n the presence of normoxia, hyperoxia and hypoxia (Gohen, Brackett and Sehwartz, 1964; Brackett, Gohen and Schwartz, 1965; Brown and Glancy, 1965;Michel, Lloyd and Gunningham, 1966; Mithoefer, Karetzky and Porter, 1968). With these methods GO2 titration curves are constructed from measurements on blood samples after equilibration of GO2, H+ and HGOs" in intracellular, interstitial and intravascular compartments has taken place. The resulting GO2 titration curves are different from the in vitro GOo titration curves of whole blood. The HGOa" concentration is less than predicted from the in vitro GO2 curve. It is thought that loss of HGO,,-from blood to interstitial fluid takes place (Shaw and Messer, 1932;Michel et al, 1966). This paper reports the GO2 titration curve in man of whole blood in vivo obtained during rebreathing of 7% GO2 in O2 (Read, 1967). During rebreathing a rapid and progressive increase of arterial H+ and arterial PCO2 occurs. The rate of increase of arterial PCO2 is about 6 mm. Hg./min. A comparison of this in vivo curve with the corresponding in vitro GO2 titration curve enables certain inferences about the rate of HGO3"" exchange to be made. MATERIALS AND METHODS.Five male patients with obstructive lung disease (age range 15-63 years) were studied. All had been referred for assessment of respiratory function and this provided the opportunity

show abstract

Section: Resultssupporting

confidence: 89%

“…after the onset of CO2 inhalation. In dogs, Cohen et al {1964) found no change in blood 3~ concentration between 1 and 6 hr. after the onset of C0:> inhalation.…”

Section: Resultsmentioning

confidence: 74%

THE IN VIVO CARBON DIOXIDE TITRATION CURVE IN MAN DURING REBREATHINC

Despas

Leigh

1970

Aust J Exp Biol Med

View full text Add to dashboard Cite

show abstract

“…Recently, the quantitative characteristics of this defense have been defined in acute studies of the acid-base response of the intact organism to stepwise increases in carbon dioxide tension (2,3). Similar observations are not available, however, for chronic hypercapnia in which defense of pH is enhanced by renal generation of bicarbonate.…”

mentioning

confidence: 99%

“…The analytical procedures have been described in a previous paper from this laboratory (2). The daily balance was calculated as the net intake minus the combined outputs in urine and stool.…”

mentioning

confidence: 99%

The Response of Extracellular Hydrogen Ion Concentration to Graded Degrees of Chronic Hypercapnia: The Physiologic Limits of the Defense of pH*

Schwartz¹,

Brackett²,

Cohen³

1965

J. Clin. Invest.

Self Cite

162

View full text Add to dashboard Cite

“…Recent studies of the "whole body" carbon dioxide titration curve have provided a physiologic description of the buffer characteristics of normal dog and man (1)(2)(3)(4)(5). They have left unanswered, however, the question of how, and to what extent, preexisting abnormalities in the acid-base status of the organism might influence the ability to defend pH during acute changes in arterial carbon dioxide tension.…”

Section: Introductionmentioning

confidence: 99%